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ANNUAL
CONGRESS
Pre-congress symposium
Long term partners
Wednesday, September 22, 2010
ALBANI Hotel - Firenze (Italy)
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Table of contentS
6
Head and neck pruritus in cats: a diagnostic and therapeutic challenge
(S. Gilbert, P. Prélaud)
14
Use of the tris-EDTA and Otodine in veterinary medicine (properties,
mechanisms of action, indications, clinical study)
(G. Ghibaudo)
15
Antimicrobial activity of Otodine®
(L. Guardabassi)
16
The use of Otodine® ear flushing solution in bacterial otitis
preliminary results of a randomized placebo controlled stud
(C Noli, S. Belova, E. Bensignor, K. Bergvall, L. Ordeix, M. Galzerano)
20
A One Health approach to helminth infections linked to dermatitis in
pets: from diagnosis to epidemiology
(L. Rinaldi and G. Cringoli)
22
Clinical aspects of dermatitis associated with D. repens in pets
(W. Tarello)
24
Miscellaneous helminths associated to skin diseases in dogs and cats
(P. Bourdeau)
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Pre-congress symposium
Long term partners
INTRODUCTION
Dear Colleagues,
It is our great pleasure to welcome you to Florence!
As Long Term Partners of the ESVD, we are proud to organize this PreCongress Symposium; we are sure that the lectures will be useful and
interesting for your professional activity.
The Long Term Partners of ESVD are also main sponsors of the annual
ESVD Congress and we are convinced that this meeting is essential for all
those who, like you, believe that updating is fundamental for continuing
professional improvement.
Once again, we sincerely hope that you have a great experience at the ESVD
and in this year’s magical venue of Florence.
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SPEAKERS
Sophie Gilbert (Belgium)
DVM, PhD, Dip. ACVD
Sophie Gilbert obtained her degree in Veterinary Medicine in 1989 from the University of Liege in Belgium. She then
worked at the same university as a Clinical Instructor in Internal Medicine and Dermatology until 1995, when she
moved to Scotland to pursue a PhD on IgE and allergic skin diseases of cats. After finishing her PhD at the University
of Edinburgh, Sophie Gilbert spent 3 years at the University of California in Davis where she completed a residency
in Veterinary Dermatology and worked as a Clinical Instructor. In 2003, Sophie Gilbert was offered a position of
Assistant Clinical Professor in Dermatology at the University of Minnesota, where she worked for 3 years until she
joined the team of professionals at New York City Veterinary Specialists in 2006. Dr. Gilbert has been lecturing
Dermatology at national and international meetings/conferences for veterinary practitioners. She has authored
numerous articles in Comparative Dermatology. Sophie Gilbert has a special interest in skin diseases of cats.
Dr. Gilbert is a Diplomate of the American College of Veterinary Dermatology, a member of the European Society of
Veterinary Dermatology, and a member of the International Society of Veterinary Dermatopathology
Pascal Prélaud graduated in 1984 from the Ecole Nationale Vétérinaire in Toulouse. In 1987 he founded CERI, a
veterinary clinical pathology laboratory in Paris, which he continues to manage. This laboratory was a pioneer in
the field of allergic testing in Europe. Pascal has worked as a specialist in veterinary dermatology since 1987. He now
works in Paris in a veterinary specialists clinic (Advetia). Member of the International Task Force on Canine Atopic
Dermatitis, he is the author of many scientific articles and lectures, mainly on allergic dermatitis in dogs and cats
and otology. He has authored three books on veterinary allergies (1991, 1999, 2008), two on ear diseases (2010) and
a book on endocrinology (2002), which has been translated into several languages. Pascal Prélaud is co-author of
the Guide de Dermatologie Féline (2000) with Dr. Eric Guaguère.
Pascal PRÉLAUD (France)
DVM, Dip. ECVD
Giovanni Ghibaudo (Italy)
DVM
Luca Guardabassi (Italy)
DVM, PhD, dip. ECVPH
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Dr. Giovanni Ghibaudo graduated in Veterinary Medicine from the University of Milan, Italy, in 1996. His activity is
concerning veterinary dermatology and clinical cytology. He works as referral dermatologist in Clinica Veterinaria
Malpensa (Samarate-Varese) and other clinics in northern and center of Italy . He made ESAVS (European School
for Advanced Veterinary Studies) Dermatology Course 1996-98. He is an ESVD (European Society of Veterinary
Dermatology) and SIDEV (Società Italiana di Dermatologia Veterinaria) Full Member. He was lecturer in National and
International Meetings SCIVAC (Società Culturale Italiana Veterinari Animali da Compagnia) and AIVPA (Associazione
Italiana Veterinari dei Piccoli Animali). Translator of Medleau & Hnilica “Dermatology of dog and cat” textbook 2°
Ed. 2007. Author, together with Dr. Noli, of «Dermatologia clinica e microscopica del cane e del gatto» textbook
Poletto Editore 2009. Author of «Principi di Video-otoendoscopia nel cane e nel gatto» textbook Poletto Editore
2010. Author of over 50 articles on Italian and International Veterinary Journals. His fields of interest are canine and
feline ear diseases and atopic dermatitis.
Luca Guardabassi graduated from Pisa University in 1994. In 2000, he got a PhD degree in Veterinary Microbiology
at The Royal Veterinary and Agricultural University (KVL) in Denmark. And in 2005, Diplomate of the European
College of Veterinary Public Health (ECVPH), University of Glasgow, UK. He is now Associate professor (“Lektor”) in
the Department of Veterinary Pathobiology, Faculty of Life Sciences (LIFE), University of Copenhagen (Danemark).
His main areas of research are antimicrobial resistance, antimicrobial therapy and bacterial zoonoses transmitted
by animals. He has established an international network with foreign groups leading research on these areas. In
recent years he has developed a strong interest in optimization of antimicrobial therapy for reducing the impact on
selection of bacterial resistance.
Over 100 international publications since 1998, including 3 book chapters, 48 articles in peer-reviewed journals, 27
oral presentations and 23 posters at conferences. His work was cited in 589 articles in international journals (Web of
Science Cited Reference Searching, 26th April 2010, date last accessed). First editor of a book on antimicrobial use in
animals published by Blackwell in 2008.
Luca Guardabassi is a member of the American Society for Microbiology, the European Society of Clinical Microbiology
and Infectious Diseases, and the Danish Microbiological Society.
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Dr. Chiara Noli graduated in veterinary medicine from the University of Milan, Italy, in 1990. After a residency at the
University of Utrecht, Holland, she obtained the European Diploma in Veterinary Dermatology in 1996. Since then
she works as referral dermatologist and dermatopathologist in Northen Italy. Dr. Noli is Past President and Founder
Member of the Italian Society of Veterinary Dermatology, Past President of the European Society of Veterinary
Dermatology and has been Board Member of the International Society of Veterinary Dermatopathology. Dr. Noli
is author of nearly 100 articles in Italian and international journals, of nine book chapters and of two veterinary
dermatology textbooks.
Chiara Noli (Italy)
DVM, Dip. ECVD
Laura Rinaldi, born on the 4 November 1973 is currently Researcher and Aggregate Professor of Veterinary
Parasitology and Parasitic Diseases at the Faculty of Veterinary Medicine of the University of Naples Federico II,
Italy. She is Associate Member of the European Veterinary Parasitology College (EVPC). Primary research areas
are epidemiology and diagnosis of parasitic diseases of domestic ruminants and pets, with particular interest in
zoonoses. She is co-author of more than 200 publications, papers published on national and international scientific
journals and proceedings of national and international conferences. She is Associate Editor of the International
Scientific Journal Geospatial Health.
Laura Rinaldi (Italy)
DVM, Aggregated professor,
PhD
After graduating in Veterinary Medicine at the University of Turin (Italy) in 1987, Dr Walter Tarello practiced in
northern and central Italy devoting special attention to the human-animal interaction of pathogens and the vectorborne diseases. A special interest in Dirofilaria spp. in pets brought him to several parts of the world including
Ukraine, Saudi Arabia, Kuwait, Dubai, Cyprus and Qatar. From 1999 till now Walter Tarello published 14 articles on the
diagnostic, clinical and therapeutic aspects of D. repens in domestic carnivorous and delivered lectures on D. repens
in Congresses held in Sweden (2003) and Ukraine (2003).
Walter Tarello (Qatar)
DVM, MA Cardiology,
MRCVS
Professor
Patrick BOURDEAU
(France)
DVM, PhD, Dip.
ECVD, Dip. EVPC
Dr. Bourdeau received his DVM degree from the Veterinary School of Maisons -Alfort in 1978 where he was then assistant/
associate professor (Unit of Parasitology) from 1978 to 1990. He then moved to Veterinary School of Nantes (now ONIRIS).
He is currently full professor in charge of the Unit of Parasitology, Dermatology, and Mycology: related clinics (including
exotic pets and zoo animals) and laboratory of diagnosis. He developed his expertise in the 4 domains traditionally
associated to Veterinary Parasitology in France. He developed and organized specialized clinics in Dermatology in MaisonsAlfort from 1988 to 1998 and simultaneously the first French Unit of Dermatology in Nantes (since 1991) associated to
(then fused with) Parasitology Unit. He is member of ECVD (1992), co-organizer of the French certificate of Dermatology
(CES) and responsible for the National diploma of Specialization (DESV). He supervised 4 residents (3 are now ECVD mbs).
Dermatology areas of interest are allergies, new concepts of therapeutics, epidemiology (clinics organized in good clinical
practice to allow validated retrospective studies) and relationship dermatology/ectoparasites and fungi. He is diplomate
of French certificate of Human and Veterinary Parasitology and Agregation of Parasitology. In 1998 he initiated the
European College of Veterinary Parasitology (with Pr Jacobs, and Genchi). The Unit focuses on teaching and research on
ectoparasites (all host species) and internal parasites (small animals and equines). Areas of interest are host/ectoparasite
interactions, biology of ectoparasites. (Ticks and fleas), activity of ectoparasiticides. He developed several National studies
on canine vectorial borne diseases in France and zoonotic or internal parasites in dogs since 2000. Since 1985 he ahs
a continuous interest on Canine Leishmaniosis (pathophysiology, diagnosis, epidemiology) and is currently member of
the reference LeishVet Group. He described several new internal or external parasites/parasitic diseases in France (i.e.
Straelensiosis). He recently conducted a Multinational European survey on Canine Leishmaniosis. He is diplomate in
Mycology of Institut Pasteur Paris. Particular interest was devoted to dermatophytes (diagnosis epidemiology control),
Malassezia and more generally dermatomycoses. The laboratory of the Unit has optimized the diagnosis of ringworm
(rapid and semi-quantitative) and identified new agents of mycoses. His PhD in Zoology and interest to exotic allowed the
development of “Unusual species medicine” ( exotic and zoo animals) both in clinics (external medicine) and laboratory
(parasitic and fungal diseases). He is also in charge of lectures to National Museum of Natural History in Paris (venomous
arthropods and marine biotoxins).
5
Head and neck pruritus in cats:
a diagnostic and therapeutic challenge
Sophie Gilbert, DVM, PhD (New York, USA), Dip. ACVD
Pascal Prélaud, DVM (Paris, France), Dip ECVD
Pruritus of the head and the neck is a common clinical feature of skin disease and reason for consultation in the cat. It
is important to establish an exhaustive list of differential diagnoses and to follow a thorough and methodical approach
to make a precise diagnosis, whereby enabling optimal treatment and management by addressing both the symptoms
and underlying cause. However, finding the exact etiology of pruritus can be challenging due to the large number of
possible underlying causes. Diagnosis involves taking a full and detailed history, a thorough physical examination, and
further diagnostic tests.
I/ Diagnostic approach
A complete history including the breed and age of the cat, together with a thorough physical examination
recording the distribution and type of lesions can substantially narrow the list of differential diagnoses.
1 • History
© Pascal Prelaud
© Pascal Prelaud
• Breed - Persan: dermatophytosis and idiopathic facial
dermatitis; Abyssinian, Siamese: behavioural disorders
• Age of onset - Juvenile and young adult cats:
dermatophytosis, ectoparasites; allergic dermatitis; older
cats: cutaneous T-cell lymphoma, thymoma-associated
exfoliative dermatitis, lymphocytic mural folliculitis.
• Life style and environment - Group housing, cat
shows: dermatophytosis, ectoparasites, flea allergic
dermatitis, viral diseases. Exposure to sun: solar keratosis,
squamous cell carcinoma. Indoor cats: behavioural, Figure 1: Idiopathic facial dermatitis in a Persian cat
allergic dermatitis.
• Seasonality - FBH (flea bite hypersensitivity) and pollen allergy, especially if the condition worsens during the
warmer times of the year in cats that spend more time outdoors during the summer months.
• Zoonotic (owner affected) - Dermatophytosis,
cheyletiellosis, notoedric mange, otodectic mange, poxvirus
(Figure 2).
• Contagious (other animals affected) - Dermatophytosis,
cheyletiellosis, notoedric mange, otodectic mange, superficial
demodectic mange (Demodex gatoi), viral diseases.
• Systemic clinical signs - Cutaneous T-cell lymphoma,
thymoma-associated exfoliative dermatitis, viral diseases
(Pox, FIV, FeLV, FHV1).
• Previous therapy and response to treatment - It is
important to ask for the precise dosage and the duration
of administration. - Drugs or vaccines administered prior
to the onset of pruritus: drug/vaccine reaction; good
response to corticosteroids: allergic dermatitis; poor
Figure 2: Small nummular ulcers symptomatic of poxvirus infection
response to inadequate (too low) doses of corticosteroids:
pemphigus foliaceus; worsening with corticosteroids: dermatophytosis, viral diseases, ectoparasites
(cats with ectoparasitosis may show initial improvement at the beginning of corticosteroid therapy,
followed by aggravation of the disease). It is important to rigorously assess flea control to ensure correct
administration (demonstration of spot on applications, list of other animals to treat, etc.).
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2. Clinical examination
Dermatological examination
Figure 4: Neck excoriations in a cat
with FBH
Figure 5: Temporal plaques and excoriations
(aeroallergen hypersensitivity)
© Pascal Prelaud
© Pascal Prelaud
© Pascal Prelaud
© Pascal Prelaud
The distribution of skin lesions and a detailed examination of affected hairs and skin can provide valuable
information about the etiology. Good lighting is essential; a magnifying hand lens with a light source can
also prove useful.
• Distribution of lesions: the sites of the initial lesions can be very informative.
• Restricted to ventral neck
- Flea infestation or FBH (Figure 4)
- Other allergic dermatitis
- Behavioural disorder
• Restricted to dorsal neck
- Flea infestation or FBH
- Other allergic dermatitis
- Behavioural disorder
- Idiopathic feline ulcerative dermatoses
• Restricted to head and neck: food allergy, FBH, atopic
dermatitis, mosquito-bite hypersensitivity, otodectic
mange, notoedric mange, trombiculiasis, herpes and pox
virus, idiopathic facial dermatitis.
- Unilateral: dermatophytosis, cat bite abscess,
Figure 3: Bilateral ulcers and crusts in a cat with pemphigus foliaceus
solar keratosis, behavioural disease.
- Bilateral, symmetrical: pemphigus foliaceus (Figure 3), drug reaction, allergic dermatitis, solar keratosis, idiopathic facial dermatitis.
- Temporal area: allergic dermatitis (Figure 5), notoedric mange, otodectic mange
- Periorificial (around the mouth and eyes): allergic dermatitis (Figure 6), pemphigus foliaceus, infectious dermatitis, drug reaction, FHV1 dermatitis, solar keratosis.
- Planum nasale/dorsal muzzle: pemphigus foliaceus, drug reaction, viral (Herpes and Pox)
(Figure 7), mosquito-bite hypersensitivity.
Figure 6: Periorificial erythema, crusts and excoriations (food
hypersensitivity)
- Chin: chin acne, Malassezia dermatitis, pyoderma, follicular demodicosis, contact allergy, eosinophilic granuloma.
- Eyes: viral (FHV1), allergy, solar keratosis.
- Mouth: viral (FHV1, pox), epitheliotropic T-cell lymphoma.
- Pinnae: mosquito-bite hypersensitivity, eosinophilic granuloma, otodectic mange, notoedric mange,
trombiculiasis, dermatophytosis, pemphigus foliaceus, drug reaction, solar keratosis, squamous cell
carcinoma (Figure 7).
- Inner aspect of pinnae: pemphigus foliaceus
- Ear canals: allergic dermatitis, otodectic mange, demodicosis, drug reaction, mural folliculitis.
• Other affected areas on the body
- Focal/multifocal lesions: dermatophytosis, vaccine-induced.
- Ventral abdomen: superficial demodicosis (Demodex gatoi), allergic dermatitis, psychogenic disorders.
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© Pascal Prelaud
- Dorsal and lumbar distribution: cheyletiellosis, FBH.
- Generalized: epitheliotropic T-cell lymphoma, thymoma-associated exfoliative dermatitis, mural
folliculitis, drug reactions, and allergic dermatitis.
Figure 7: Actinic keratosis: erythema of dorsal aspect of pinna
• Type of lesion and aspect of the skin:
Papules, crusts, excoriations - Small focal to diffuse papular eruptions with mild crusting are the most common
lesions in “miliary dermatitis”. The lesions are easier to detect by palpation. The etiology of these crusted papules is
multifactorial and miliary dermatitis is a descriptive term rather than a specific disease. This reaction pattern can be
seen in FBH, atopic disease, food allergy, folliculitis, ectoparasitosis, dermatophytosis, pemphigus foliaceus and drug
reactions, with FBH being the most common. Bacterial folliculitis may occur as a secondary complication to any of
these differentials and can aggravate the number and severity of the papules and crusts.
Plaques – Clearly demarcated, alopecic, moist erythematous plaques are characteristic of eosinophilic plaque.
They are usually located on the ventral abdomen, thorax and medial aspect of the hind legs, but may occur
anywhere. Eosinophilic plaque is not a specific disease entity, but a reaction pattern that may have several possible
underlying causes. It is one of three variants of the eosinophilic granuloma complex. In most cases it is the
cutaneous manifestation of an allergy (FBH, food allergy, atopic dermatitis). Less common underlying diseases
are ectoparasitosis (cheyletiellosis, notoedric mange, otodectic mange, and superficial demodicosis) and bacterial
infections. However, secondary bacterial infections are not unusual. The differential diagnoses for eosinophilic
plaques include neoplasia and Pox virus.
Ulcers – Ulcers are usually the result of self-trauma. They can also occur as a focal non-pruritic unilateral or bilateral
lesion on the philtrum of the upper lip or adjacent to the canine tooth, where it is referred to as “indolent ulcer, rodent
ulcer, or eosinophilic ulcer”. It is not a diagnosis per se but a reaction pattern with multiple etiologies. Occasionally,
eosinophilic ulcer may occur elsewhere on the body. Eosinophilic ulcer is another component of the eosinophilic
granuloma complex. The etiologies of these eosinophilic lesions include genetics, allergic dermatitis with excessive
grooming, and chronic oral inflammatory diseases. Many other diseases can induce ulcers, including infections of any
type, solar keratosis, pemphigus foliaceus, drug reactions, idiopathic ulcerative dermatitis and neoplasia.
Exfoliative dermatoses, scales, crusts. All forms of inflammatory skin disease may alter the rate of epidermal turnover
or create inflammatory debris that can mix with surface scales; secondary exfoliative dermatosis is therefore a common
finding in pruritic skin disease. Underlying causes include ectoparasitosis, allergic dermatitis, dermatophytosis,
Malassezia dermatitis, pyoderma, pemphigus foliaceus, drug eruptions, epitheliotropic T-cell lymphoma, thymomaassociated exfoliative dermatitis, idiopathic lymphocytic mural folliculitis, and viral dermatitis.
Comedones/follicularcast:lymphocytic mural folliculitis , follicular demodicosis, bacterial folliculitis, dermatophytosis,
Malassezia dermatitis, idiopathic facial dermatitis
Otitis: Allergic dermatitis, Otodectic mange, demodicosis, pemphigus foliaceus.
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Figure 9: Same cat as Figure 8: proximal
dry ceruminolith
© Pascal Prelaud
© Pascal Prelaud
© Pascal Prelaud
Figure 8: Neck erosions due to ear
ceruminolith
Figure 10: Neck erosions caused by licking as
a displacement activity in an atnxious cat
General examination/Systemic signs
• Non-specific (pyrexia, lethargy, decrease appetite): paraneoplastic (thymoma-associated exfoliative dermatitis),
epitheliotropic T-cell lymphoma, viral (FeLV, FIV, Pox), degenerative mucinotic mural folliculitis.
• Gastrointestinal signs: food hypersensitivity
• Respiratory signs: polyps, thymoma-associated exfoliative dermatitis, herpes virus dermatitis.
• Ocular signs: allergy, FHV1
• Neurological: otitis media (Horner syndrome), otitis interna
• Otoscopic examination: external otitis, ceruminolith, otitis media (Figures 8-9)
• Behaviour: NB: facial pruritus is rarely behavioural in origin, but it can induce abnormal behaviour.
3. Diagnostic procedures
A standardized sequence of tests can be followed in many cases. The sequence should be tailored to suit
each case and should take owner compliance and economic factors into consideration.
Determine whether an infectious agent is involved
Most of these tests may be performed at the first visit as they are easy to perform, relatively inexpensive,
and will give a good indication as to the underlying cause of the pruritus.
• Flea combing and hair sampling are very effective means of identifying a wide range of parasites besides fleas and
flea dirt, such as Cheyletiella spp.
• Skin scrapings are one of the easiest yet most important tests to perform in any diagnostic work up. Many important
parasites can be identified on a skin scraping including Otodectes, Notoedres, Trombicula autumnalis (harvest mite),
Demodex cati, and Felicola subrostratus (lice). However, the absence of Cheyletiella sp and Demodex gatoi does not
rule out the disease.
• Sellotape can be used to pick up ectoparasites, especially Cheyletiella spp and Demodex gatoi. Staining the sellotape
with the purple Diff-quick solution can reveal Malassezia organisms and bacteria.
• Hair pluck and trichogram. The trichogram can be used to detect Cheyletiella spp (eggs), and may also reveal
Demodex cati, Lynxacarus radovsky (eggs), lice (eggs) and dermatophytes (hyphae and spores). It is also an easy way
of confirming pruritus (broken hairs).
• Skin cytology (Figures 10-11-12): If erosions or ulcers are present, cytology is a rapid way of determining the presence
of secondary bacteria infection. In addition, it can give an indication of the underlying etiology. In cases of primary
pyoderma, the bacteria are intracellular, usually in the neutrophils; in the cat bacteria can sometimes be found inside
eosinophils. Eosinophils are very common inflammatory cells that can be found in a variety of feline disorders, but
most commonly with ectoparasites, allergies, and in some forms of eosinophilic granuloma complex (granulomas and
plaques). In Malassezia dermatitis, cytology reveals the presence of Malassezia organisms. Also, it is not uncommon to
visualize fungal spores or hyphae in cats with dermatophytosis.
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© Pascal Prelaud
© Pascal Prelaud
Figure 11: Cytological examination of facial erosions (RAL555 X1000):
Acantholytic cell with non-degenerated neutrophils (pemphigus foliaceus)
© Pascal Prelaud
Figure 12: Cytological examination of facial erosions (RAL555 X1000):
Degenerated neutrophils with intra and extra-cocci (secondary pyoderma)
Figure 13: Cytological examination of facial erosions (RAL555 X1000):
Eosinophils and free eosinophilic granules (eosinophilic plaque)
• Wood’s light examination is a quick and cheap test to detect the
presence of dermatophytes. However, it is often misinterpreted and
lacks sensitivity, as only approximately 50% of Microsporum (M.)
canis strains are detected and it does not reveal M. gypseum and
Trichophyton spp.
• Fungal culture is the most sensitive and specific method to
diagnose or rule out dermatophytosis. This diagnostic test is
usually performed at a later appointment, unless dermatophytosis
is strongly suspected.
• Response to rigorous flea treatment. All cats living in areas where
fleas are commonly found should undergo strict flea treatment to rule
out FBH. However, response to such treatment may take 1 to 2 months.
• Response to acaricidal therapy. A trial of lime sulphur dip should
be performed at the first visit if superficial demodicosis is suspected
and Demodex gatoi cannot be found. An antiparasitic treatment
trial should also be performed if cheyletiellosis is suspected but the
parasite is not found.
• Faecal examination may reveal the presence of Demodex gatoi
mites or eggs, Cheyletiella spp, fleas, Dipylidium caninum or other
endoparasites.
Diagnosing allergic dermatitis
• Flea combing, faecal examination, response to rigorous flea
treatment, intradermal testing with flea extract. It is important to
remember that FBH is one of the most common causes of pruritus
in cats. Also, a strict flea control should be part of the diagnostic
workup in a pruritic cat, unless the history and clinical signs allow
ruling out this possible diagnosis.
• Dietary elimination trial (8 to 10 weeks) followed by re-challenge
with original diet. A dietary elimination trial may be initiated at the
first visit, especially if the pruritus is year round and if the history is
suggestive of a food allergy.
• Intradermal testing (IDT) and allergen-specific IgE serology. IDT
and allergen-specific IgE serology may be performed at a later stage
of the diagnostic work-up if other underlying causes have been ruled
out (see below). These tests are expensive, and can be also positive
in a non atopic cat. They should therefore only be performed if the
client wishes to pursue allergen-specific immunotherapy.
Other further diagnostic tests
• Skin biopsy may prove very useful, either by limiting the differential diagnosis, giving classes of diseases to pursue,
or in some cases, giving a final diagnosis. Some specific diseases, e.g. infectious (viral), parasitic, and autoimmune
(pemphigus foliaceus), can be diagnosed on a skin biopsy. Neoplastic diseases can only be diagnosed definitively with
a biopsy. Multiple samples should always be taken and samples should be sent to a clinical pathologist with specific
expertise or interest in skin disease.
• PCR: Pox virus, FHV1, FIV (in case of lymphocytic mural folliculitis)
• Imaging:
CT scan of bullae, internal ear
Radiography of the bullae: polyps, otitis media
Chest radiographs: thymoma-associated exfoliative dermatitis
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II/ Important considerations
It is important to remember that some head/neck pruritic dermatoses are much more common than others;
these dermatoses are therefore likely to be included in the differential diagnosis and diagnostic workup of
the majority of the cases. Allergies, e.g. FBH, aeroallergens, and food allergies, and pemphigus foliaceus
are the most common causes of pruritus in the cat in referral practice. Some ectoparasites, e.g. Otodectes
cynotis and Neotrombicula spp are also common in general practice. Although dermatophytosis is also
common in cats, it is not always pruritic. Less common causes of pruritus include other ectoparasites,
such as notoedric mange, pediculosis, cheyletiellosis, and superficial demodicosis, and Malassezia
dermatitis. Trombiculiasis is a seasonal ectoparasitosis that may be relatively common during late
summer and autumn in some parts of the world, and superficial demodicosis caused by Demodex gatoi
may be common in some parts of the US, e.g. Texas, while it may be rare in other regions of the world.
Notoedric mange and pediculosis can also be common is some regions (e.g. southern Europe). Unlike in
the dog, pyoderma and follicular demodicosis are rare in the cat. Other rare dermatoses that may or may
not be pruritic are epitheliotropic T-cell lymphoma, thymoma-associated exfoliative dermatitis, idiopathic
lymphocytic mural folliculitis, and viral dermatitis (herpes virus, pox virus, FeLV, and FIV).
III/ Treatment of head/neck pruritus in the cat
Once the underlying cause is known, specific treatment can be instigated. Initially, short term symptomatic
treatment may be required to improve the cat’s wellbeing, and that of the owner! The majority of pruritic
diseases in the cat cannot be cured; they therefore require a combination of specific and symptomatic
therapy to control the symptoms and improve quality of life.
1. Etiological treatments
Once the underlying cause has been diagnosed, a specific treatment may be sufficient to resolve the pruritus.
2. Symptomatic treatments (allergic and idiopathic pruritus)
It is important to determine each owner’s tolerance for their cat’s level of pruritus. The choice of symptomatic therapy
may differ depending on whether it will be used in the short term or long term. Some symptomatic treatments (e.g.
corticosteroids, cyclosporine) may increase the cat’s susceptibility to viral diseases; FeLV, FIV, and FHV1 status should
therefore be checked prior to long-term anti-inflammatory therapy.
Systemic corticosteroids
The best choice for rapid control of pruritus
Oral short acting corticosteroids are preferable to injectable long acting (depot) corticosteroids, as they can be
discontinued at any time, thus enabling the assessment of treatment efficacy during trial therapy or to limit the
development of adverse effects.
When oral corticosteroids are used long term, tapering doses should be given according to the response observed.
The initial dose is usually higher than in dogs and is given daily until remission is obtained (usually 1 week to 10 days).
The dose is then gradually reduced to the lowest alternate day dosage that will control the symptoms:
• Prednisolone or methylprednisolone 1 to 2 mg/kg q24h
• Dexamethasone 0.1 to 0.2 mg/kg or 0.25 to 1 mg/cat q24h.
• Triamcinolone 0.2 to 0.4 mg/kg q24h.
Begin with the least potent corticosteroid (prednisolone 1 mg/kg q24h); if this does not produce the desired result a
more potent one can be tried.
If long term treatment is needed, antihistamines and essential fatty acids can help to reduce the effective dose of
corticosteroids.
Tachyphylaxis (a rapid decrease in response to treatment) is common following long term corticosteroid therapy. In
such case, cyclosporine may prove effective. 11
Antihistamines
Antihistamines can prove effective for the long term treatment of allergic pruritus. The most commonly used
antihistamines are cetirizine 1 mg/kg q24h, cyproheptadine 8 mg/cat TID, and hydroxyzine.
There are no placebo-controlled studies into the efficacy of antihistamines in the control of idiopathic or allergic head
and neck pruritus in cats, but the sedative effect of first generation antihistamines can be helpful and in some case
they can help to decrease the dose of steroids.
Cyclosporine
Cyclosporine A is a very potent alternative to corticosteroids for the treatment of allergic or idiopathic pruritus in the cat.
The recommended dose ranges from 5 to 8 mg/kg q24h, PO. Eosinophilic granuloma complex may require higher doses (up
to 12.5 mg/kg q24h). It may be possible to reduce the dose to alternate days (EOD) after 4 to 6 weeks. The lesions may stay in
remission or be controlled with twice weekly administrations in some cats.
The pharmacological properties of cyclosporine are significantly different in cats versus dogs:
• Longer half life, enabling early EOD administration.
• High individual variations in absorption; it is therefore important to measure plasma cyclosporine concentrations in cases of
failure.
Major short term adverse reactions include lethargy and softened stools.
Rare cases of fatal toxoplasmosis have been reported in the literature. They are most likely due to primary infections in treated
cats. To minimize this risk:
• Keep the cat indoors and feed an industrial or previously frozen diet.
• Administer clindamycin during the first few months of treatment, although in our experience this can induce severe adverse
gastrointestinal reactions.
• Administer clindamycin when the cat exhibits signs of illness (lethargy, anorexia, etc.).
• Never prescribe cyclosporine in a cat with a positive Toxoplasma IgM serology
Topical corticosteroids
Potent topical corticosteroids such as triamcinolone or hydrocortisone aceponate spray (once daily) can be very
effective in controlling allergic pruritus in cats. However, particular care should be taken in cats because of their thin
skin and the potential risk of inducing skin fragility. Compliance is often difficult in our experience. Tacrolimus
Tacrolimus is a macrolide immunosuppressant that belongs to the same family as cyclosporine. It can be used safely
in the cat (SID or BID) in the treatment of dirty face syndrome, and eosinophilic plaque or granuloma. The cat should
wear an Elizabethan collar following application, as irritant reactions may occur during the first few days of application,
and also to prevent licking and limit systemic absorption.
Other topical treatments
iSome antipruritic lotions and pump spray products containing lidocaine, diphenhydramine, or pramoxine may be
helpful as adjunctive therapy in cases of localized pruritus. Physical restraint
• Elizabethan collars can be useful to limit self-trauma during the initiation of symptomatic treatment. They are also useful
to prevent the cat from licking off topical medication and therefore interfering with the drug’s absorption and efficacy.
However their use should be limited because it is stressful and in some cases, it may not be possible to remove them.
• Bandannas and neck wraps are useful and non stressful methods of preventing self-mutilation in cases of neck pruritus
or idiopathic ulcerative dermatosis. They can also facilitate the absorption of topical medications.
• Bandaging the face and neck may also limit self-trauma or enhance the efficacy of topical medications (photos).
They may be a good alternative to systemic therapy. Bandages should be removed every 2 days to reassess the lesions.
• “Soft-paws” are soft plastic covers that are glued onto the nail. They are marketed as an alternative to de-clawing. Softpaws may be also useful in preventing self-induced trauma.
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© Pascal Prelaud
© Pascal Prelaud
Figure 15: Large erosions with severe secondary pyoderma on the neck
© Pascal Prelaud
Figure 16: Same cat as Figure 15: bandage to prevent cell damage and licking of the topical antibiotic.
Figure 17: Same cat as Figure 16: after one week of topical treatment
Conclusion
Diagnosing head and neck pruritus in the cat can prove frustrating because of the lack of efficient allergy testing in
this species. It is therefore important in refractory cases to find a long term treatment with minimal side effects.
Calcineurin inhibitors, (i.e.cyclosporine), are currently one of the best treatments for cats with idiopathic head and
neck pruritus.
13
Use of the tris-EDTA and Otodine in
veterinary medicine
(properties, mechanisms of action, indications, clinical study)
Giovanni Ghibaudo DVM ( Clinica Veterinaria Malpensa, Samarate (Varese) – Italy – www.ghibaudo.it / [email protected])
EDTA (ethylene diamine tetra acetic acid) has bactericidal action, in fact it binds divalent cations (Mg++and Ca++)
and this enhances membrane permeability and it alters ribosome stability. EDTA in buffer solutions (pH 8 with
tromethamine -Tris) increase efficacy against Pseudomonas aeruginosa (Gray et al. 1965; Robert et coll. 1970).
Tris-EDTA potentiates antibiotic activity binding to metal ions, which compete with aminoglycosides for cell wall
receptors that allow them into bacteria; tris-EDTA has been shown to have good synergistic effects when used in
combination with amikacin and neomycin (Sparks et coll. 1994).
For gram-negative bacteria (e.g. E. coli and P. aeruginosa) certain surface-active agents (e.g., EDTA, cationic peptides,
lysozyme, and cell wall-active antibiotics) seem to be able to deregulate autolysins associated with the peptidoglycan
layer so that they are artificially activated and lyse the bacteria (Goldschmidt et al. 1967; Watt et coll. 1994). In 2003
an in vitro study has shown that tris-EDTA is capable of reducing the minimum inhibitory concentration (MIC) of
enrofloxacin against ciprofloxacin resistant Pseudomonas aeruginosa.
These results suggested that tris-EDTA exhibits a sparing in vitro effect on the MIC of enrofloxacin against ciprofloxacin
resistant Pseudomonas aeruginosa and may benefit treatment of otitis externa infections with both susceptible and
resistant Pseudomonas bacteria (Gotthelf 2003).
Chlorhexidine digluconate is a biguanide and it has antiseptic (bacteria and fungi) action on bacterial cellular
membrane inducing intracellular precipitation content and ATP inhibition; it is disinfectant at low %, not irritant and
not inactivated by organic substances.
Some human studies showed that EDTA increases the activity of chlorhexidine digluconate against pathogens
(Wooley et al. 1983). Increased bactericidal activity was obtained by the addition of a chelating agent (EDTA) and a
buffer (Tris) enabling a low concentration of chlorhexidine (0.01 per cent) to be effective against Escherichia coli,
Pseudomonas aeruginosa Proteus mirabilis and Streptococcus faecalis (urinary pathogens) (Harper 1983). Moreover,
in another study, chlorhexidine/tris-EDTA was more active compared with chlorhexidine alone against several
species of organisms including Escherichia coli, Proteus mirabilis, Pseudomonas species, Staphylococcus aureus and
Staphylococcus epidermidis (Harper and Epis 1987).
Chlorhexidine at concentrations less than 0.20% is safe in canine ears: a solution containing 0.20% chlorhexidine did
not induce vestibular or cochlear neurotoxicity following installation into the external ear canals of dogs with intact
and surgically perforated tympanic membranes (Merchant et al.1995). In veterinary medicine potentiation of antibiotic
activity by EDTA-tromethamine against clinically isolated gram positive resistant bacteria was demonstrated in vitro
(Farca et al. 1994 & Farca et al. 1997).
Tris-EDTA /chlorhexidine 0,15% combination (Otodine ®) was made for the first time and copyright by I.C.F. s.r.l. Palazzo
Pignano (Cremona) Italy in 2004 . This combination has antibacterial and synergic effect moreover it is capable of
reducing the MIC. In 2004 a clinical study was presented at the World Congress of Veterinary Dermatology in Vienna
by Ghibaudo et coll.: Evaluation of the in vivo effects of Tris-EDTA and chlorhexidine digluconate 0.15% solution in
chronic bacterial otitis externa: 11 cases.
The objectives of this study were to evaluate in vivo tolerance, and antimicrobial and clinical activities of a topical
otic preparation containing EDTA tromethamine (Tris) and chlorhexidine digluconate 0.15% solution (Otodine®) in
dogs with chronic bacterial otitis externa. Eleven dogs were included. The affected ears were filled with the solution
once daily during a 2-week period. Dogs were evaluated on days 0, 14 and 28. Three clinical parameters (exudate,
erythema, pain) and three cytologic parameters (Malassezia, cocci, rods) were scored (0-4 scale) by otoscopic and
cytological examinations of otic exudate. Bacterial cultures were performed at each time point. If there were bacteria
on cytological examination on day 14, the dogs were treated with the original product, with the addition of enrofloxacin
(5%) applied 10 min after the original product, for a further 2 weeks.
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All 11 cases yielded isolates of resistant gram-negative bacteria; gram-positive bacteria were also isolated from six
of 11 dogs. On day 14, six of 11 dogs were negative on culture examination; on day 28, 10 of 11 were negative and only
one case had a positive culture. On day 14, clinical and microbial scores (cytology) were reduced by 54.6 and 71.1%,
respectively, and by 85.7 and 94% on day 28. All cases reported good tolerance of the treatment.
The results show that this ear solution was helpful in the management of chronic bacterial otitis externa in dogs and was
well tolerated. There seems to be a synergistic effect of the combination of Tris-EDTA/chlorhexidine digluconate 0.15%
solution, and an antimicrobial agent (enrofloxacin) against resistant gram-positive and gram-negative bacteria.
References
Farca AM, Nebbia P, Re G: Potentiation of antibiotic activity by EDTA-tromethamine against three clinically isolated gram-positive resistant bacteria. An in vitro investigation. Vet Res Commun;18(1):1-6, 1994.
Farca AM, Piromalli G, Re G: Potentiation of antibiotic activity by EDTA-Tris on the activity of antibiotics against resistant bacteria associated with otitis, dermatitis and cystitis. J Small An -Practice;38:243-5, 1997.
Ghibaudo G.; Cornegliani L.; Martino P.: Evaluation of the in vivo effects of Tris-EDTA and chlorhexidine digluconate 0.15% solution in chronic bacterial otitis externa: 11 cases. Poster at the 5th World Congress of Veterinary
Dermatology. Vienna 2004 Veterinary Dermatology 2004, 15 (Suppl. 1), 65
Goldschmidt MC, Wyss O: The role of Tris in EDTA toxicity and lysozyme lysis. J Gen Microbiol 47: 421-431, 1967.
Gotthelf L.N. Evaluation of the in vitro effect of Tris-EDTA on the minimum inhibitory concentration of enrofloxacin against ciprofloxacin resistant Pseudomonas Aeruginosa. Proceedings 19th Annual Congress of ESVD-ECVD,
Tenerife 2003 145.
Gray GW, Wilkinson SG: The action of ethylenediaminetetra-acetic acid on Pseudomonas aeruginosa. J Appl Bact 28(1): 153-164, 1965.
Harper WE. Simple additives to increase the activity of chlorhexidine digluconate against urinary pathogens. Paraplegia 1983 Apr; 21(2):86-93
Harper WE, Epis JA. Effect of chlorhexidine/EDTA/Tris against bacterial isolates from clinical specimens Microbios. 1987 51(207):107-12
Merchant SR, Neer TM, Tedford BL, et al. Ototoxicity assessment of a chlorhexidine otic preparation in dogs. Prog Vet Neurol 1993; 4:72-75.
Roberts NA, Gray GW, Wilkinson SG: The bactericidal action of ethylenediaminetetra-acetic acid on Pseudomonas aeruginosa. Microbios 2 (7-8):189-208, 1970.
Sparks TA, Kemp DT, Wooley RE, Gibbs PS. Antimicrobial effect of combinations of EDTA-Tris and amikacin or neomycin on the microorganisms associated with otitis externa in dogs. Vet Res Commum. 1994 18(4): 241-9
Watt, S. R., and A. J. Clarke. Role of autolysins in the EDTA-induced lysis of Pseudomonas aeruginosa FEMS Microbiol. 1994 Lett. 124:113–120
Wooley RE, Jones MS: Action of EDTA-Tris and antimicrobial agent combinations on selected pathogenic bacteria. Vet Microbiol Jun;8(3):271-80, 1983.
15
Antimicrobial activity of Otodine®
Dr Guardabassi - Associate Professor of Clinical Microbiology, Department of Veterinary Disease Biology, Faculty of Life
Sciences, University of Copenhagen (Denmark)
Small animal veterinarians are currently facing one of the most threatening antibiotic resistance problems ever
observed in the history of veterinary medicine. During the last five years we have observed a dramatic increase in the
occurrence of multidrug-resistant bacteria in dogs and cats worldwide. Some of these bacteria, especially methicillinresistant staphylococci, are virtually resistant to all systemic antibiotics available in veterinary medicine. The
characteristic multidrug resistance phenotype of these bacteria poses a serious threat to animal health and a difficult
therapeutic challenge to veterinarians. In perspective this situation is further complicated by the lack of development
of new antimicrobial drugs for veterinary use, which is likely to continue for many years to come.
Recent studies indicate that topical antiseptics represent a valid therapeutic approach to combat antibiotic resistant
bacteria in veterinary dermatology. This presentation summarizes the results of two complementary studies of
Otodine®, an ear cleanser containing 0.15% chlorhexidine and Tris-EDTA. Chlorhexidine is a biguanide compound that
exerts bactericidal activity by membrane disruption and is mainly active against Gram-positive organisms. Tris-EDTA
is known to improve the effects of various antimicrobials by affecting the permeability of the outer membrane in
Gram-negative bacteria, thereby enhancing drug penetration into the bacterial cell. Combination of Tris-EDTA and
chlorhexidine results in a synergistic effect, allowing the use of low doses of chlorhexidine that are not ototoxic.
In the first study, the in vitro antimicrobial activity of Otodine® was evaluated using a collection of 150 bacterial isolates
representing the most common pathogens associated with canine otitis. Each microorganism was incubated for 30
minutes in serial two-fold dilutions of Otodine® and plated on nutrient agar to assess survival. The product displayed
an excellent in vitro activity against Staphylococcus pseudintermedius and Malassezia, which were eliminated after
30 minutes of exposure to 1:64 dilution of the product. Killing of Gram-negative organisms such as Pseudomonas
aeruginosa and Proteus mirabilis required lower dilutions (1:8 and 1:4, respectively). Although the concentrations
required for complete killing varied considerably depending on the type of microorganism, the combination of
chlorhexidine and Tris-EDTA was shown to be active against all pathogens involved in canine otitis. Interestingly,
multidrug-resistant strains were equally killed by Otodine® as susceptible strains. This should be regarded as an
important property since it ensures that usage of the product does not co-select for multidrug resistance.
In the second study, the in vivo efficacy of Otodine® as the sole form of antimicrobial treatment was investigated
in 19 dog ears with clinical signs of otitis externa. The product was administered twice a day for 10 days and the
efficacy of the treatment was evaluated on the basis of otoscopy, cytology and culture. In 18 cases (95%), a significant
reduction in inflammation, exudation and pain was observed from day 1 to days 11 and 18 (one-way ANOVA t test, p
range from 0.0564 to 0.9354). Fourteen cases (74%) were cured successfully as indicated by disappearance of all
presenting symptoms, 50% or higher reduction of the clinical scores on both days 11 and 18, normal cytology and
owner’s satisfaction with treatment. The mid-term success rate was 63% since two of these dogs had relapses during
the four weeks following the end of treatment. The results showed that Otodine® can be used successfully as a first
choice for treatment of otitis externa without any additional antibacterial or antifungal therapy.
Considering the frequent recourse to antibiotics for treatment of otitis externa, the use of ear antiseptics as the sole
form of antimicrobial treatment may be a useful therapeutic approach to minimize antibiotic usage and selection of
antibiotic resistant bacteria in dogs. The high antimicrobial activity of antiseptics has been confirmed by following in
vitro studies of various shampoo products. In addition to clinical efficacy and low selection potential, topical antiseptics
have various advantages compared with systemic antibiotics, including their broad spectrum of antimicrobial action,
complementary non-antimicrobial properties, and selective action limited to the site of application
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THE USE OF OTODINE EAR FLUSHING
SOLUTION IN BACTERIAL OTITIS
PRELIMINARY RESULTS OF A RANDOMIZED
PLACEBO CONTROLLED STUDY
C Noli (1), S. Belova (2), E. Bensignor (3), K. Bergvall(4), L. Ordeix(5), M. Galzerano (6),
Introduction
Bacterial otic overgrowth and purulent otitis are
common conditions of dogs, particularly in allergic
animals. Frequent ear washing with a desinfecting agent
is a very important component of a successful therapy of
bacterial otitis, even more now that multi-drug resistant
bacteria are commonly isolated from ear infections (1).
Otodine contains chlorhexidine 0.15% and Tris EDTA,
both of which have established efficacy against bacteria,
and is a product designed for application into the
external ear canal (2). A preliminary study suggested
that Otodine alone was able to significantly reduce
clinical signs and bacterial and neutrophil numbers in
bacterial otitis (3, 4).
Aim of this randomized blinded study was to evaluate
the efficacy of Otodine in the treatment of ears affected
with bacterial overgrowth, with or without Malassezia
pachydermatis, or purulent otitis, and compare it to that
of the vehicle only.
5. Table 1 - Pruritus
*
*
!
Table 2 - Erythema
Materials and methods
This was a multicenter randomized double blinded
vehicle-controlled field study. Animals were privately
owned dogs recruited by the investigators from their
every day practice. Dogs were not included if they
were affected by otitis due to foreign bodies, ear mites
or neoplastic disease of the ear canal, had medium to
severe stenosis, evidence of ruptured ear drum, or had
been treated with topical otologic products or systemic
antibiotics of any nature in the 10 days before inclusion.
Bacterial overgrowth and purulent otitis were diagnosed
by cytology of smears of cerumen collected with a
cotton swab introduced in both ear canals, and stained
with a modified Write’s stain.
Animals were randomly assigned to two groups: one
treated with placebo, one treated with Otodine once
daily. A further small pilot group received the Otodine
twice daily.
Ear washings were administered daily for 4 weeks.
After a first ear flushing performed by the investigator,
if necessary under general anaesthesia, the following
ones were done at home by the owners.
Clinical signs (pruritus/pain, erythema, oedema,
quantity and odour of the exsudate) were evaluated on
day 0, 14 and 28, with a 0-4 point scale (0=absent, 1=mild,
2=moderate, 3=severe, 4= very severe).
*
*
!
Table 3 - Oedema
!
17
Bacteria and neutrophil semiquantitative (0-4 scale) counts on cytological samples were performed at each time point
from each ear, with the following scoring system:
Bacteria
0 - no bacteria
1 - less than 5 bacteria/HPF
2 - 5/10 bacteria/HPF
3 - 10/25 bacteria/HPF
4 - > 25 bacteria/HPF
Neutrophils
0 - absent
1 - present<1x10HPF
2 - present 1-5x10HPF
3 - present 5-10x10HPF
4 - present >10x10HPF
Table 4 - Quantity of exsudate
Within-group comparison of the baseline characteristics
(age, weight and clinical parameters) was performed
using a Friedman analysis of variance (ANOVA). The
test of Bonferroni was usedto evaluate the post hoc
differences between the groups. Between-group
comparison of the reduction of clinical and cytological
parameters was performed using the Paired-Samples
vStudent’s t-test among three groups. P-value < 0.05 was
considered statistically significant. Analyses have been
performed using Predictive Analytics SoftWare 18.0 for
Windows.
Results
Eighteen ears of 11 dogs were included into the study.
Eight ears were given the placebo, 10 Otodine once daily
28 days. Two dogs in the Otodine group were lost to
follow up after the first recheck, and their results were
carried forward to Day 28 following ITT methodology.
The small pilot group receiving Otodine twice daily was
composed of three dogs for a total of five ears.
There was no significant difference between groups
for age, weight, clinical or cytological parameters at
Day 0, with exception of bacteria, which were higher in
the vehicle group if compared to the small pilot group
receiving Otodine twice daily.
Both at D14 and at D28, in the active once daily treatment
group there was a significant improvement of pruritus,
erythema, quantity of exsudate, odour, and bacterial
counts. At D28 there was a significant improvement of
neutrophil counts.
In the vehicle group only the parameters quantity of
exsudate and odour did improve significantly at D14 and
number of bacteria at D28.
Comparison of average scores between the two groups
are presented in tables 1-7, with asterisks indicating
significant improvements from D0. Percentages of
improvements between D0 and D28 are descriptively
reported in table 8.
*
*
*
*
!
Table 5 - Odour
*
*
*
*
!
Table 6 - Bacterial counts
*
*
!
*
(1)Ospedale Veterinario Cuneese, Borgo S. Dalmazzo, Italy, (2) Department of Therapy, Institute of Veterinary Medicine and Animal Science, Estonian, University of Life Sciences, Tartu, Estonia, 3) Dermatology Referral
Service, Rennes-Cesson, Paris and Nantes, France, (4) Department of Clinical Sciences, Swedish University of Agriculture, Uppsala, Sweden, (5) Hospital Ars Veterinaria, Barcelona, Spain, (6) University of Turin, Italy
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The animals in the small pilot group which received
Otodine twice daily showed worse results after 14 and 28
days than the group treated once daily for all parameters
considered, with the obvious exception of quantity of
exsudate (table 9). No statistically significant difference
was found between groups.
Considering the type of otitis reported at day 0, a
significant improvement of parameters was achieved
with Otodine both in animals affected with cerminous
otitis and in those affected with purulent otitis. The
latter showed a greater improvement in oedema than
the former.
No adverse event was reported in either group.
Table 7 - Neutrophil counts
*
!
Table 8 - Percentage of score between D0 and D28 - comparison of Otodine and vehicle
Discussion
It is known that Triz-EDTA and chlorhexidine contained
in Otodine are able to potentiate the efficacy of
topical antibotics when given 30-60 minutes after its
administration, and its use as daily ear washing associated
with topical antibiotic in bacterial otitis is a common
therapeutical protocol.
This study suggests that Otodine is able to significantly
reduce - on its own - clinical signs and cytological
parameters of bacterial otitis, if used daily for a 14-28 days.
No real advantage was seen if used twice daily versus
once daily, albeit in a small number of animals and ears.
Instructions to apply Otodine twice daily might make for
poorer compliance than once daily application and is not
recommended at this stage.
Both bacterial overgrowth and purulent otitis showed
significant improvement, making Otodine an useful tool
in all cases of otic bacterial infection. Due to its capability
of significantly decrease bacterial counts even in purulent
otitis, it can be considered an interesting option in cases of
multi-drug resistant bacterial infections, when a decrease
in antibiotic use or a non-antibiotic alternative is preferred.
References
!
Table 9 - Percentage of score resduction between D and D28 - Otodine once versus twice daily
!
Oliveira LC, Leite CA, Brilhante RS, Carvalho CB. Comparative study of the microbial profile from bilateral canine otitis externa. Canadian Veterinary Journal, 2008, 49(8):785-788.
Guardabassi L, Ghibaudo G, Damborg P. In vitro antimicrobial activity of a commercial ear antiseptic containing chlorhexidine and Tris-EDTA. Veterinary Dermatology 2010, 21: 282-286.
Ghibaudo G, Cornegliani L.,Martino P. Evaluation of the in vivo effects of tris-edta and chlorhexidine digluconate 0.15% solution in chronic bacterial otitis externa: 11 cases. Veterinary Dermatology 2004, 15:41-69.
Ghibaudo G, Cornegliani L, Martino P. Efficacia e tollerabilità di una soluzione con Tris-EDTA e clorexidinadigluconato 0,15%. Summa maggio 2007
19
A One Health approach to helminth
infections linked to dermatitis in
pets: from diagnosis to epidemiology
Dr Laura Rinaldi (Department of Pathology and Animal Health, Faculty of Veterinary Medicine, University of Naples
Federico II, Naples, Italy), Giuseppe Cringoli
The link between animal and human infections and the global environment is unquestionable. This awareness
has contributed to an increasing appreciation of the interdependency of human, animal and ecosystem health
within the transdisciplinary “One Medicine–One Health” approach to global health (Conrad et al., 2009).
Helminth infections linked to dermatitis in pets include those caused by the hookworms (e.g. Ancylostoma
caninum in dogs and A. tubaeforme in cats), the threadworm Strongyloides stercoralis and the filarial worm
Dirofilaria repens.
The hookworm Ancylostoma caninum is the most widespread species of the genus Ancylostoma (de Silva et
al., 2006). It is distributed in the tropics and warm temperate areas throughout the world, whereas in Europe,
A. caninum occurs mainly in the southern part (Grandemange et al., 2007). A. caninum is one of the most
pathogenic gastrointestinal parasites of dogs. The adults live in the small intestine and the life cycle is direct.
Infective larvae (L3) can be transmitted orally or percutaneously; also the transmammary transmission is very
frequent in dogs.Typical morbid sequelae include wasting and anaemia, but a sustained chronic infection can
lead to death (Heukelbach and Feldmeier, 2008).
The threadworm S. stercoralis is distributed worldwide in warmer climates, including Europe. The parasite is
capable of both parasitic and free-living life cycles. The parasitic phase is composed entirely of females and the
life cycle is direct. S. stercoralis infects the host through percutaneous, oral or transmammary transmission in
addition to autoinfection. Clinical disease varies from inapparent to severe enteritis and pneumonia.
Following percutaneous infection by A. caninum and/or S. stercoralis dermatitis occurs in the area of larval
penetration and the lung is affected by migrating larvae.
A. caninum and S. stercoralis also poses a considerable public health risk, because the parasites can infect humans,
causing creeping eruptions also known as larva migrans cutanea and/or larva currens (Provic and Croese, 1996).
Dirofilaria infections are vector-borne parasitic infections mainly of dogs and cats and, in Europe, they are caused
by D. immitis and D. repens. The life cycle of both parasites consists of five larval stages developing both in an
intermediate host that also acts as vector and in a definitive vertebrate host. Male and female D. immitis adult
stages occur in the pulmonary arteries and right heart chambers and causes heartworm disease in dogs and
cats while D. repens is found mainly in subcutaneous tissues (Figure 1). Adult female Dirofilaria releases embryos
(microfilariae) into the blood (Genchi et al., 2005, 2009). The intermediate hosts and vectors are mosquitoes
of the family Culicidae with nearly 70 species susceptible to the parasite and thus considered potential vectors
(Vezzani and Carbajo, 2006). Culex pipiens and Aedes
albopictus are mostly implicated as natural vectors
of Dirofilaria in Italy (Genchi et al., 1992; Cancrini et al.,
2007).
Both Dirofilaria species are zoonotic, and the human
infections caused by D. repens are increasing in
Europe (Pampiglione and Rivasi, 2000). Transmission
of dirofilariosis is dependent upon the presence of
sufficient numbers of infected, microfilaraemic hosts,
susceptible mosquitoes, and a suitable climate to
permit extrinsic incubation of Dirofilaria in the mosquito
intermediate host (Genchi et al., 2009).
Figure 1: Adult D. repens from the subcutaneous tissue of a dog
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The scientific interest concerning dirofilariosis has tended to focus mostly on D. immitis because of its pathogenicity
and consequent veterinary importance (Cringoli et al., 2001) though the increasing spreading of D. repens toward
European countries (Genchi et al., 2009) and its concern as zoonotic infection (Pampiglione et al., 2001; Szénási
et al., 2008) have renewed the interest for this species. Recently, the overall aspects of D. immitis infections,
from biology to clinic, prevention and treatment have been reviewed by McCall et al. (2008). Furthermore,
the establishment of American Heartworm Society since 1967 in the USA and the European Dirofilaria Society
since 2009 in Europe testify to the worldwide efforts to promote awareness, encourage research and provide
updated guidelines for the diagnosis, treatment and prevention of these infections.In pets, dermatitis linked to D.
repens infections are very common whereas those linked to D. immitis infections are quite rare or at least underreported.
The current situation of ancylostomosis, strongyloidosis and dirofilariosis in Europe will be discussed with
particular emphasis on “parasitological” aspects of these helminthes, including epidemiology and diagnosis.
Concerning epidemiology, geospatial tools - as Geographical Information Systems (GIS), Global Positioning System
(GPS), satellite-based Remote Sensing (RS) and Virtual Globes (e.g. Google EarthTM) – for monitoring, geo-positioning,
collating, exploring, visualizing and analyzing health data, including data on helminth infections linked to dermatitis
in pets are very useful in order to better understanding the epidemiology and control of these nematodes of human
and veterinary importance (Rinaldi et al., 2006).
Concerning parasitological diagnosis, novel multivalent
copromicroscopic techniques as the FLOTAC techniques (Figure
2), are available for a sensitive and accurate diagnosis of A.
caninum and S. stercoralis in dogs (Cringoli et al., 2010).
In conclusion, it is advisable the advancement and standardization
of epidemiological and diagnostic procedures within a One Health
approach to helminth infections linked to dermatitis in pets.
The FLOTAC apparatus (from Cringoli et al., 2010).
References
Cancrini, G., Scaramozzino, P., Gabrielli, S., Di Paolo, M., Toma, L., Romi, R., 2007. Aedes albopictus and Culex pipiens implicated as natural vectors of Dirofilaria repens in central Italy. J. Med. Entomol. 44, 1064-1066.
Conrad, P.A., Mazet, J.A., Clifford, D., Scott, C., Wilkes, M., 2009. Evolution of a transdisciplinary «One Medicine-One Health» approach to global health education at the University of California, Davis. Prev. Vet. Med. 92, 268-274.
Cringoli, G., Rinaldi, L., Maurelli, M.P., Utzinger, J., 2010. FLOTAC: new multivalent techniques for qualitative and quantitative copromicroscopic diagnosis of parasites in animals and humans. Nat. Protoc. 5, 503-515.
Cringoli, G., Rinaldi, L., Veneziano, V., Capelli, G., 2001. A prevalence survey and risk analysis of filariosis in dogs from the Mt. Vesuvius area of southern Italy. Vet. Parasitol. 102, 243-252.
de Silva, L.M., Miranda, R.R., Santos, H.A., Rabelo, E.M., 2006. Differential diagnosis of dog hookworms based on PCR-RFLP from the ITS region of their rDNA. Vet. Parasitol. 140, 373-377.
Genchi, C., Di Sacco, B., Cancrini, G., 1992. Epizootiology of canine and feline heartworm infection in Northern Italy: possible mosquito vectors. In: Soll, M.D. (Ed.), Proceedings of Heartworm Symposium’92. American Hearytworm
Society, Baravia, IL, pp. 39-46.
Genchi, C., Rinaldi, L., Cascone, C., Mortarino, M., Cringoli, G., 2005. Is heartworm really spreading in Europe? Vet. Parasitol. 133, 137-148.
Genchi, C., Rinaldi, L., Mortarino, M., Genchi , M., Cringoli, G., 2005.Climate and Dirofilaria infection in Europe. Vet. Parasitol. 163, 286-292.
Grandemange, E., Claerebout, E., Genchi, C., Franc, M., 2006. Field evaluation of the efficacy and the safety of a combination of oxantel/pyrantel/praziquantel in the treatment of naturally acquired gastrointestinal nematode
and/or cestode infestations in dogs in Europe. Vet. Parasitol. 145, 94-99.
Heukelbach, J., Feldmeier, H., 2008. Epidemiological and clinical characteristics of hookworm-related cutaneous larva migrans. Lancet Infect Dis 8, 302-309.
McCall, J.W., Genchi, C., Kramer, L.H., Guerrero, J., Venco, L., 2008. Chapter 4, heartworm disease in animals and humans. Adv. Parasitol. 66, 193-285.
Pampiglione, S., Rivasi, F., 2000. Human dirofilariasis due to Dirofilaria (Nochtiella) repens: an update of world literature from 1995 to 2000. Parassitologia 42, 231-254.
Pampiglione, S., Rivasi, F., Angeli, G., Boldorini, R., Incensati, R.M., Pastormerlo, M., Pavesa, M., Ramponi, A., 2001. Dirofilariasis due to Dirofilaria repens in Italy, an emergent zoonosis: report of 60 new cases. Histopathology 38,
344-354.
Prociv, P., Croese J., 1996. Human enteric infection with Ancylostoma caninum: hookworms reappraised in the light of a “new” zoonosis. Acta Trop. 62, 23-44.
Rinaldi, L., Musella, V., Biggeri, A., Cringoli, G., 2006. New insights into the application of geographical information systems and remote sensing in veterinary parasitology. Geospat. Health 1, 33-47.
Szenasi, Z., Kovacs, H., Pampiglione, S., Fioravanti, M.L., Kucsera, I., Balazs, T., Tiszlavicz, L., 2008. Human dirofilariosis in Hungary: an emerging zoonosis in central Europe. Wien. Klin. Wochenschr. 120, 96-102.
Vezzani, D., Carbajo, A.E., 2006. Spatial and temporal transmission risk of Dirofilaria immitis in Argentina. Int. J. Parasitol. 36, 1463-1472.
21
Clinical aspects of dermatitis
associated with D. repens in pets
Walter Tarello, DVM, MACardio - C.P. 1644, 06129 Perugia, Italy - Email: [email protected]
Dirofilariasis is a parasitic disease endemic in Southern and Eastern Europe, caused by two species of ovoviviparous
mosquito-borne zoonotic filarial nematodes: Dirofilaria immitis, a parasite of the cardio-vascular system, and
Dirofilaria (Nochtiella) repens, a parasite of the subcutaneous connective tissue of dogs, cats, wild carnivores and
humans (1).
Increasing numbers of autochthonous cases of D. repens have been reported in recent years, with prevalence
ranging 0-30%, from Germany, Slovakia, Czech Republic, Hungary, Ukraine, Russia, Austria, Switzerland, northern
France and the Netherlands, as a consequence of climate changes together with increased pet travel across
Europe (2).
Dogs, cats and wild carnivores are final hosts of D. repens and constitute the only source of accidental
infestation for humans, in the presence of a competent population of mosquito vectors, including the Asian tiger
mosquito Aedes albopictus and Culex pipiens (2).
Human dirofilariasis appears in the form of subcutaneous, conjunctival and pulmonary nodules often
confused with neoplastic tumors (1). Itching, swelling and tenderness are common signs in human beings (3).
Italy is the country most affected, recording >300 cases, followed by Sri Lanka, France, Ukraine and Greece (1).
Endemic areas of canine and feline subcutaneous dirofilariasis have been described in these countries, in accord
with the observation that geographic distribution of human dirofilariasis due to D. repens follows the distribution
observed in the animal reservoirs (1).
D. repens is not widely known to cause chronic pruritic dermatitis and general signs in affected dogs and cats
(4-6). The adult worms reside in the subcutaneous tissues, living up to 43 months, and release microfilariae that
circulate in the blood (2). Although the parasitosis may appears asymptomatic, a seasonal variance exists in the
number of circulating microfilariae, with peaks in August-September, associated with cyclic clinical manifestations,
such as pruritus, erythema and alopecia, caused by mechanical, toxic and immuno-mediated actions of the
parasite (4).
In a control group of microfilaraemic asymptomatic dogs, 43% developed pruritic skin lesions within 5
months (4). Experimentally infected dogs show microfilaraemia 6 months after inoculation even in the presence
of only one D. repens male (2).
Mosquitoes suck the blood of infected dogs, ingesting microfilariae (larvae L1) which develop into L2 and
infective L3 larvae within 10-20 days. During a mosquito’s blood meal L3 larvae penetrate into the subcutaneous
tissues of a dog or cat, where they molt to L4 larvae and remain for 5-6 months, before developing into adults
(3-6).
Males parasites measure 5-7 cm. and females 10-17 cm. in length. Cuticular longitudinal ridges constitute the main
difference to D. immitis (1-6).
Unsheathed D. repens microfilariae measure 325-375 microns in lenght and 7-8.3 microns in width, showing a
cephalic space roundish and empty as well as a tail larger than those of D. immitis and Aacanthocheilonema
(Dipetalonema) reconditum (3).
Diagnosis is based upon the presence of pruritic skin lesions, the finding of D. repens microfilariae and a negative
test for circulating D. immitis antigens (2-3). The combined use of concentration techniques (Knott, Difil) and
heartworn antigen tests improves the accuracy to 98% (4). Differential diagnosis includes atopic dermatitis and
other pruritics ecto-parasitosis (4).
Due to their location, adult nematodes are rarely found, occasionally being recovered from skin nodules (2).
Nevertheless, the detection of microfilariae is diagnostic for Dirofilaria infections (3-6).
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LARVAE (L4)
ADULTS
INFECTIVE LARVAE
(L3)
AEDES
ANOPHELES
CULEX
MICROFILARIAE (L1)
(L3)
(L1)
(L2)
MOSQUITOES
Dermatological signs observed in 100 canine clinic cases were as follows (2-6): pruritus (100%), erythema (79%),
papulae (62%), focal or multifocal alopecia (55%), hyper-cheratosis (18%), crusting (14%), nodules (12%), acantosis (5%),
eczema (3%), pyoderma (3%) and oedema. Generally, 85% of dogs had at least one lesion on the posterior part of
the body. Signs other than dermatological were as follow: conjunctivitis (46%), anorexia (35%), vomiting (26%), fever
(25%), lethargy (20%) and lymph-adenomegaly (10%).
The virulence of filarial parasites seems to be influenced by underlying concurrent infections (3-6). The apparent
opportunistic role of D. repens might well explain the presence of asymptomatic carriers, the concurrent observation
of non-dermatological signs and the development of dermatitis in a subgroup of parasitized dogs (4).
Eradication of underlying conditions, followed by the anti-filarial therapy with adulticide (moxidectin, doxycycline)
and microfilaricide (ivermectin) medicaments is essential to a complete cure and disappearance of microfilaraemia (4),
the speed of recovery depending upon the duration of the disease and severity of lesions (4). Preventive medication
with oral microfilaricidal drugs for heartworm disease is effective against D. repens microfilariae (5-6).
During the last few years, animal infestation with D. repens has been recognized in new areas of the world,
including the Alps, Ukraine and the Middle East (3-6). Strict quarantine regulations seldom prevent propagation of
D. repens, because the infestation becomes patent only after 6-10 months and the adult parasite can live 2-4 years in
the subcutaneous tissues of dogs (2-6). Suitable climate and vectors can therefore facilitate the spread of this filarial
nematode (2). In conclusion, D. repens is not as harmless as currently considered and apparently it is an opportunistic
agent, often manifesting together with other infections showing both general and dermatological signs (2-6).
References
(1) Pampiglione S. and Rivasi F. Human dirofilariasis due to Dirofilaria (Nochtiella) repens: an update of world literature from 1996 to 2000. Parassitologia, 2000, 42: 231-254.
(2) Pantchev N., Norden N., Lorentzen L., Rossi M., Rossi U., Brand B. and Dyachenko V. Current surveys on the prevalence and distribution of Dirofilaria spp. in dogs in Germany. Parasitology Research, 2009, 105: 63-74.
(3) Tarello W. Autochthonous Dirofilaria (Nochtiella) repens infection in dogs in Kuwait. Zoonosis and Public Health, 2008, 55: 328-30.
(4) Tarello W. Cutaneous lesions in dogs with Dirofilaria (Nochtiella) repens infestation and concurrent tick-borne transmitted diseases. Veterinary Dermatology, 2002, 13: 267-274.
(5) Tarello W. Retrospective study on the presence and pathogenicity of Dirofilaria repens in 5 dogs and 1 cat from Aosta Valley. Schweizer Archiv fur Tierheilkunde, 2003, 145 (10): 465-9.
(6) Mazurkevic A., Vasylyc N., Avramenko T., Velichko S., Tarello W. and Varodi E. Adult Dirofilaria repens nematodes in a cat from Kiev, Ukraine. Veterinary Record, 2004, 155 : 638-639.
23
Miscellaneous helminths associated
to skin diseases in dogs and cats
Patrick BOURDEAU - Dip ECVD – Dip EVPC – PhD - Professeur Agrégé - Unit of Dermatology/Parasitology CE/Mycology
- ONIRIS, Nantes-Atlantic College of veterinary medicine and food sciences
Skin conditions associated to helminths in dogs and cats are rare in comparison to other cutaneous parasites.
Consequently it is difficult and unusual for the practitioner to include such hypothesis in the differential diagnosis.
In case of clinical manifestation due to helminths, it is also difficult to choose the most appropriate diagnostic
sequence and samples. Another particularity of these diseases is the almost mandatory involvement of specialized
laboratories for an ultimate identification and diagnosis. Finally the actual knowledge on most of these conditions
remains limited and they could be not so infrequent in many European countries. Many remain probably neglected
and underdiagnosed (i.e. Dirofilaria repens).
As a general rule helminths are involved in skin condition in five situations:
• Transcutaneous infecting larvae.
The infective larvae present in the environment are able to cross the skin barrier.
• Pathologic effects of disseminating stages (i. e. microfilariae).
The adults are present in the host (dog or cat in this situation). They produce eggs or embryos that are disseminated
through blood (or lymphatic) stream. These stages reach the skin capillaries and are responsible of skin lesions.
• Normal location in skin (cutaneous parasite) in a normal or unusual host.
The adults (or larvae) of these helminths develop in the skin (generally subcutis). The parasites are normally
adapted to this location in their natural their host. Skin lesions occur in special condition or when the parasite
develops in an unusual host.
• Aberrant location or development in a normal or unusual host.
Many helminths undergo complex migration in their host. Sometimes these migrations become aberrant resulting in
an abnormal location like subcutis. This is also frequently the case when such helminths invade non-specific hosts.
• « Paraparasitic syndrome »: skin lesions are linked to parasites that are located in places other than skin.
Amongst the three major groups of parasitic helminths, skin lesions due to the class of Nematodes are by far the
most frequent, cestodes are occasionally involved and trematodes remain anecdotic or poorly defined.
Comments will be limited to condition described in dogs or cats other than Dirofilaria sp. (refer to other
presentations); most of them are common to the 2 hosts.
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I/ Skin condition due to infecting larvae
« Pelodera dermatitis »
Pelodera Strongyloides: Larva and adult (microscopic observation. X 25 )
found in the environment of an infested dog (P. Bourdeau).
Pelodera dermatitis in a Dogue de Bordeaux.
Erythematous and alopecic patches. In this case
the lesions are not limited to the ventral part of the
body (P. Bourdeau)
Pelodera dermatitis. Histopathology (HE Stain Low magnification). Tranversal
and longitudinal sections of a larava in the infudibular part of the hair follicle,
surrounded by a mixed inflammatory infiltrate (folliculitis, perifolliculitis) (
Courtesy F. Degorce LAPVSO).
Pelodera dermatitis is due to larval stages of Pelodera (P. strongyloides) or Rhabditis sp. (R. axei…). These are in
fact non-parasitic, free-living, rhabditids. These Nematodes are very abundant and common in vegetal soil. The
larvae normally feed and develop on the soil; they may accidentally survive in skin of various mammals (wildlife
or domestic). The infection is caused by contact of the skin with the contaminated soil. The larvae tend to enter in
hair follicles were they may survive. These larvae do not go further in their life cycle and finally escape from the
skin or degenerate.
The larvae may induce variable degrees of pruritus, oozing, erythema, crusts and alopecia. Lesions are most often,
but not necessarily, located in skin areas in contact with soil. Pelodera dermatitis has been described in a variety of
mammals including rodents in wildlife. It has been also described in several species of domestic animals including
dogs. Most cases in dogs are seen in animals living in rural areas or with an access to a garden.
The observation of the larvae can be done very simply from skin scrapings to the condition to use mineral oil. Larval
stages in deep follicular position can be also found in histopathological sections from skin biopsies. However the
identification of larvae remains difficult and they have to be differentiated from other larvae of nematodes that
could accidentally contaminate the skin surface. A definitive identification is obtained from the observation and
morphology of adults collected in the environment of the infected dog.
Control is mainly based on the eviction or avoidance of contaminating substrate and the interest of a specific
treatment is questionable.
« True infective larval stages »
A comparable situation is due to authentic infecting forms of potentially common parasites like Strongyloides
stercoralis or Ankylostomids (hookworms) in dogs and cats. These larvae are present
in soils contaminated with faeces issued from animals with a patent intestinal infection.
It is typically seen in collectivities like kennels of hunting dogs.
The infected animals develop an erythematous, possibly papular, alopecic dermatosis
often accompanied with peripheral adenomegaly. Here again the lesion is mainly
located to skin areas in contact with the soil, typically the extremities. A pododermatitis
with hyperkeratotic pads and reactive popliteal lymph nodes is considered suggestive.
Digestive signs (diarrhoea, melaena) can be present in heavily or very young infested
dogs.
Skin scrapings and histopathology are not reliable methods although the route of
infection is also mainly the hair follicle. Larvae do not remain in the hair follicle and
rapidly migrate in the skin or degenerate A positive coproscopy is a required but not
a sufficient argument for final diagnosis.
Ankylostoma dermatitis. Erythema alopecia and crusts
The treatment is mainly based on the control of the digestive hookworm infection, disinfection
(P. Bourdeau).
of the environment and symptomatic treatment of skin lesions or Strongyloides.
25
Cercarial dermatitis is also called swimmer’s itch in humans. The condition is due to larval stages of Schistosomids
parasites of aquatic birds (ducks). These parasites are very common in wild fauna in Europe. The infecting
furcocercarias are released in fresh water in summer by intermediate hosts (gastropods). They reach the surface
of water to invade transcutaneously the skin of ducks. They may penetrate the skin of human beings swimming in
lakes at these periods and the condition is now quite common in many countries. The question of the description
of such condition in dogs, frequently exposed, remains open.
Other helminths are known to occasionally infect transcutaneously their hosts like spirurids (Gnathostoma sp).
Gnathostoma spinigerum is a nematode parasite of stomach in cats and dogs in many areas (Asia, Americas…). The
infection results most often from the ingestion of various vertebrates that act as paratenic hosts. However infecting
larvae are able to cross the skin. The condition is well described in humans, in which a very long larva migrans
episode may occur, including skin location. Little information is available on these skin lesions in dogs and cats.
II/ Skin condition and disseminating stages
« Microfilarial dermatitis »
A variety of nematodes (Filaroidea) are able to produce circulating embryos (microfilariae).
Typically these microfilariae can be more abundant in blood capillaries or in lymphatics
depending of the species of parasites.
A dermatitis caused by microfilariae of Dirofilaria immitis is well known and described (not
detailed here), producing erythema, alopecia, variable pruritus on extremities, ears … Although
Dirofilaria repens also produces microfilariae a dermatitis is rarely observed.
Other filarids in the skin of dogs could produce microfilarial dermatitis, most of them
Microfilaria of D. immitis ( X 40
belonging to the genus Dipetalonema (Acanthocheilonema): D. grassii, D. reconditum, D.
Histochemistry
staining).
The
morphology of the different species
dracunculoides.
of microfilaria is often unreliable for
identification and mixed infection
The histopathology is potentially suggestive but rarely diagnostic. One may observe a
may occur. Special stainings or
molecular methods are useful for a
granulomatous to pyogranulomatous dermatitis with a perivascular or interstitial infiltrate,
final identification (P. Bourdeau
Eosinophils and plasmocytes may be abundant. Microgranulomas containing fragments
suggesting larvae of nematodes have been described.
The diagnosis will be theoretically based on a three steps approach: first the isolation/
observation of microfilariae from capillary blood smears or after blood concentration (i.e. Knott
method) for Dirofilaria species (see details in other presentations) or, in case of subcutaneous
parasites, also from skin samples (biopsies…) placed in a drop of saline on a microscopic slide.
The second step is a precise identification of the species. The identification of microfilariae
Multiples nodules due to Dirofilaria
based on morphology is difficult and cytochemistry or molecular biology can be useful. The
repens in a Labrador crossed dog
(Courtesy N.Tarpataki).
third step is a clinical response to an anthelminthic treatment: microfilariae are easy to control
but procedures for the control of adults are not always defined.
III/ Cutaneous, subcutaneous helminths in normal or
occasional hosts
Theses parasites do not produce any clinical sign in normal condition. These parasites are
occasionally responsible for ulcers, inflammation or nodules.
The most common is probably Dirofilaria repens that may produce nodular and/or ulcerative
lesions both in dogs and cats. This parasite is now recognised as autochthonous is many
European countries (see corresponding presentation). Dipetalonema dracunculoides is a
parasite of carnivores and primates, mainly present in warm countries and also southern Europe.
Dipetalonema grassii is a parasite of subcutaneous tissue of dog transmitted by Rhipicephalus
sanguineus. It is found in Southern Europe.
Dirofilaria repens in subcutis
surrounded by granulomatous
inflammation (Histopathology HE
stain X 2)(P. Bourdeau).
Dipetalonema reconditum is also a widely distributed subcutaneous filariid transmitted by ticks or fleas.
Dracunculus medinensis is found in Tropical areas of Asia and Africa. The female lays embryos by piercing the skin when
the host enters in water. Embryos develop in an Intermediate host (crustacean, sub microscopic in size). The Infection
occurs by drinking water containing intermediate hosts. D.insignis is observed in racoons and dogs fin North America.
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Other helminths may rarely develop in the skin like Anatrichosoma, (A. cutaneum a Capillariid) or Brugia sp. (Filaria).
The cytology of the nodules may occasionally reveal the presence of embryos (or eggs in case of Anatrichosoma).
Most often the diagnosis is made from the observation of (multiple) section of parasitic elements on histopathology
resulting in an imprecise identification in most o cases. Consequently the research and identification of microfilariae is
necessary (see above). A precise diagnosis remains (dissection of nodules isolation and identification of worms).
IV/ Erratic parasites
Spirocerca lupi. Anterior extremity of adult. (X4).
Usually the adult worms inhabit the oesophagus
wall. Aberrant migrations, occasionally result in fully
developed adults in various location including the
skin. (P. Bourdeau)
Thick and brightly red Nematode in a lymph node:
Spirocerca lupi (P. Bourdeau).
Subcutaneous metacestodosis due to Taenia
crassiceps larvae in a the axillary area of a Dachshund
(P. Bourdeau).
Many helminths may have erratic locations that include the skin (mainly
subcutis). This occurs in two situations: the development in an abnormal
host or aberrant migrations in their normal host.
Probably one of the most frequent is the aberrant migration of Dirofilaria
immitis (see specific presentation) resulting in the local development of
immatures.
Most of the helminths that undergo a blood Stream migration for their development
before to reach a final location may induce aberrant skin lesions.
- It is also typically illustrated by spirocercosis in dogs. It is due to a Spirurid
Nematode (Spirocerca lupi) normally parasite of oesophagus. It is widely
distributed on all continents although only occasionally found in dogs in
Western Europe. The life cycle includes insects (coleopteran) as intermediate
host and likely paratenic hosts. The infection occurs by ingestion of infective
L3 larvae. The parasite normally starts a complex process of retrograde
arterial migration from gastric arteries to thoracic aorta and mediastinal
area. Aberrant migrations are not rare in various internal organs and skin
(subcutaneous). Nodules and abscesses may develop. They contain large
reddish nematodes. Identification is based on dissection of the nodule and
identification in laboratory.
- Occasionally Ascarids can be involved in the development of cutaneous/
subcutanous nodules in dogs and cats.
- Subcutaneous cysticercosis in the dog is due to the development in
subcutaneous tissues of Cysticercus longicollis. The adult of this cestode
is Taenia crassiceps, a very common parasite of red fox that occasionally
may also develop in dogs. Larvae are normally parasite in rodents (voles…)
that act as intermediate hosts. In these rodents the parasite is responsible
for the growth of subcutaneous parasitic masses, most frequently located
in cervical area and anterior part of the body. The definitive host is infested
by predation on infested rodents. The particularity of these larvae as
compared to other cysticerci that simply grow in the host is their ability to
proliferate indefinitely by multiple budding resulting in an infection stricto
sensu. Several cases of canine cysticercosis have been described in Europe
and particularly in France. Dogs become accidentally intermediate hosts.
The parasites proliferate in subcutaneous, and possibly internal location,
forming nodules. These nodules are fluctuant, several centimetres in size
occasionally perforated. They contain multiple whitish contractile vesicles
(1 to five millimetres). There is no effective treatment and the prognosis is
very poor
Similarly, other larval stage of cestodes may develop in their regular
definitive host. Echinococcus granulosus and Tetrathyridium (larval stage
of Mesocestoides) have been described in the hypodermis of dogs.
The diagnosis of these parasites requires a specialized laboratory.
Taenia crassiceps larva (Cysticercus longicollis).
Size 5mm. The invaginated scolex is seen at the top
and multiple buds develop at the opposite end. (P.
Bourdeau)
27
V/ Other effects
Various other skin conditions have been attributed to the presence of internal parasites. They could be due
to distant effects from parasites located in the digestive tract as a « paraparasitic effect ». It is known that
nematodes (particularly Toxocara) may produce a variety of antigens or other bioactive molecules that may
interfere with immune system at the intestinal but also general level. As an example the role of Toxocara canis
larvae in the pathophysiology of atopy / asthma in humans has been proposed. The skin could reveal these
effects, most of them of clinically low specificity. The indirect effects of nutriments spoliation like poor haircoat,
scaling, is classically admitted. The relationship between ventral pruritus and or ventral impetigo in puppies
and Toxocara infection is controversial. Abdominal pain and licking on flank area and its relationship with
trichuris is contested as well. Finally the classical «scooting» revealing anal pruritus associated to impaction
inflammation of anal sacs induced by intestinal helminths, remains the most consensual. It is considered
mainly linked to proglottids released by Taenia sp or more frequently Dipylidium caninum.
Conclusion
Helminths related dermatoses are rarely seen in dogs and exceptional in cats and few have been really
described in the literature. Several autochthonous parasites may be involved. The general suspicion will
include accurate epidemiological information that may suggest special risks of exposure to helminths like
mode of life (i.e.; kennels: lack of hygiene and hookworms, Toxocara, Trichuris, Pelodera; hunting/predation
and Spirocerca, Larvae of Cestodes), origin of the dogs or enzootic areas for exotic parasites like Dirofilaria,
Spirocerca, Gnathostoma, Dracunculus. It is important to look for such situations in dogs that travelled to
exotic warm countries. Apart Pelodera/Rhabditis dermatitis, most of the cases cannot be easily diagnosed by
direct examination. The demonstration of a simultaneous infection by adult stages is obtained by appropriate
diagnostic methods. Many of these conditions appear as a unique or multiple subcutaneous nodules mimicking
tumours, abscesses or other type of granulomas (Foreign bodies, mycotic, bacterial, myiasis). Initial cytology
from such nodules is rarely informative and surgical excision is required. It is of importance to check the
presence of a parasite in every nodule before to submit it to histopathology. In such case it has to be sent
in ethanol to a laboratory of parasitology as histopathology will hardly results in a precise identification.
Moreover precise information lacks on the paraparasitic syndrome (i.e Toxacara).
Due to the anecdotic observation of these conditions, treatment protocols are generally not validate.
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Long term partners
TABLE I HELMINTHS AND SKIN IN DOGS AND CATS
Group
Species
Clinical signs (skin)
Comments
Diagnosis (elements)
Transcutaneous infestation
Ankylostoma sp.
Uncinaria stenocephala
Ankylostomidae L3
Pruritic dermatitis
- Exclusion of other causes for dermatitis
Erythema
Simultaneous hookworm
infection ( small intestine)
Pododermatitis
Peripheral lymphadenopathy
- positive coprology
± compatible histopathology
± Isolation of larvae in the environment
Rhabditidae L3
Strongyloides stercoralis
Paules (follicular and non
follicular)
Simultaneous strongyloidosis
(intestinal)
Furcocercarias
Schistosoma mansoni
Cercarial dermatitis ?
Simultaneous
“Schistosomosis”.
- Response to treatment
- Epidemiological condition
(rivers and lakes)
Schistosoma japonicum
Erythema, papules (non follicular)
Exotic.
Heterobilharzia
americana
- Exclusion of other causes
- Positive coprology (difficult and variable)
“ Swimmer’s itch”
Likely but poorly defined in
dogs
Schistosomids of birds?
Epidemiology
Other?
Pseudoinfestation
Free nematodes
Pelodera sp.
Erythema
Likely underdiagnosed
- Positive scrapings
(rhabditids)
Rhabditis sp.
Variable pruritus
No digestive signs
± intrafollicular larvae in histopathology
- Isolation and identification of adults in the
close environment
Cutaneous helminths
Nematodes
Dirofilaria immitis
Microfilariae
(other species?)
Erythema pruritus
Quite frequent in enzootic
areas
Ulcers
Thin skin areas
Adults in abnormal
hosts
± histopathology
- Diagnosis of heartwrom infection
Not rare
Adults in normal hosts
- Isolation, identification of circulating
microfialriae ( blood)
Dirofilaria repens
Erythema,oedema, nodules
Dipetalonema
(Acanthocheilonema)
Nodules, plaques, oedema
Dracunculus sp.
Nodules, plaques, oedema
Anatrichosoma
Erythema, plaques,crusts
- Observation isolation, identification of adult
worm in lesions
Underdiagnosed
- Accurate identification
Exceptionnal
Exceptionnal
(histopathology suggestive D.N.repens )
Exotic
Exceptionnal
Exotic
- Suggestive eggs (Capillaria like) in lesions
or from exctracted adult worms
Cestodes
Taenia crassiceps larvae
Fluctuant nodules
Likely underdiagnosed
- Cyst like granuloma containing multiple
vesicules with multitple buddings,
- Analysis of hooks from scolex
(cysticercosis)
Abnormal location (migration) in skin
Nodules ( extremities..)
Dirofilaria immitis
- Extraction of immatures (long worm)
Immature stages
- Histopathology compatible
- Simultaneously heartworm positive
- Extraction of immature or adults
Spirocerca lupi
Nodules ( trunk...)
Occasional in enzootic areas
- Histopathology compatible
- Simultaneous positive coprology ( eggs)
- Extraction of immatures
Dioctophyme renale
Nematodes in usual
host
- Simultaneous positive urinanalysis ( eggs)
Exotic
Gnathostoma sp
Nodules, plaques
Angiostrongylus vasorum
-Extraction of immatures
Rare
Toxocara sp.
Skin inflammation
- Extraction of immatures
- Simultaneous positive coprology( eggs)
Histopathology compatible to suggestive
simultaneous positive coprology ( eggs)
Exceptionnal
- Exclusion of other causes
Dissemination of L1
- Simultaneous vascular Angiostrongylosis
- Response to treatment
Nematodes in
Abnormal host
Larval cestodoses
Lagochilascaris minor
Nodules ( neck..)
Sparganum
Tetrathyridium
Exotic
- Epidemiology
Exceptionnal
- Adults and eggs in lesions
Exotic or rare
- Exctraction and identification of larvae
Skin lesions due to internal helminths
- Exclusion of other causes
Dipylidium
Cestodes
Nematodes
Anal pruritus
Taenia
Pruritus…
Ascarids (Toxocara) ?
- Diagnosis of digestive parasitism
- Response to treatment
AND OTHERS….
29
COMPLEMENTARY READING
General papers and books: Bourdeau P. Diagnostic expérimental des dermatoses parasitaires : II les Helminthes.- Les Indispensables de l’Animal de Compagnie – Dermatologie Prat. Med. Chir. Anim. Comp (1991), 59 – 63.
Bourdeau P. Diagnostic expérimental des dermatoses associées aux Helminthes.- L’Indispensable de Dermatologie. AFVAC- Ed. Medcom. (2009), 101-111.
Euzeby J. Les dermatoses parasitaires du chien. Note 1. Generalites et dermatoses parasitaires prurigenes. Revue de Medecine Vétérinaire. (1974), 125(8/9) 1131-1149.
Gross T. L. et al. Skin diseases of the dog and the cat : clinical and histopathological findings 2nd Edition. Blackwell Science. Ames. (2006), 932 p.
Scott D.W., Miller W.H. and Griffin C.E. Muller and Kirk’s Small Animal Dermatology 6th Edition. W.B. Saunders Cy. Philadelphia (2001), pp 431 – 440.
Pelodera: Bourdeau, P . Cas de dermatite a rhabditides (Pelodera strongyloides) chez un chien. Point-Vétérinaire. (1984), 16(80): 5-10.
Morisse, B.; Stoye, M.; Pfleghaar, S. Pelodera-dermatitis in a Staffordshire terrier. Pelodera-Dermatitis bei einem Staffordshire Terrier. Kleintierpraxis. (1994), 39 (11), 805-811.
Cagnasso, A.; Peirone, B. Dermatitis due to Pelodera strongyloides in a dog. Citation disponible uniquement
Dermatite da Pelodera strongyloides nel cane. Summa. (1988), 5 (1), 74.
Horton, M. L. Rhabditic dermatitis in dogs. Modern Veterinary Practice. (1980), 61 (2), 158-159.
Saari S A M, Nikander S E. Pelodera (syn. Rhabditis) strongyloides as a cause of dermatitis - a report of 11 dogs from Finland. Acta Veterinaria-Scandinavica. (2006), 48: 48.18.
Ankylostoma/Uncinaria: Banerjee D. Early stage of infection of Ancylostoma caninum in dogs and mice. Indian Journal of Medical Research. (1973), 61(4), 475-481.
Bowman, D. Det al. Hookworms of dogs and cats as agents of cutaneous larva migrans. Trends in Parasitology. (2010), 26 (4),
Gnathostoma: Daengsuang S et al. Development of adult Gnathostoma spinigerum in the definitive host (cat and dog) by skin penetration of the advanced third-stage larvae. Southeast Asian Journal of Tropical Medicine and Public Health.
(1970),1(2): 187-192.
Ménard, A.et al. Imported cutaneous gnathostomiasis: report of five cases. Transactions of the Royal Society of Tropical Medicine and Hygiene. (2003), 200-202.
Dirofilaria: Ananda, K. J. et al. Methods for identification of microfilaria of Dirofilaria repens and Dipetalonema reconditum. Journal of Veterinary Parasitology. (2006), 20 (1), 45-47.
Casiraghi, M. et al. A simple molecular method for discriminating common filarial nematodes of dogs (Canis familiaris). Veterinary Parasitology. (2006), 141 (3/4), 368-372.
Dyachenko, V. et al. Dirofilaria repens infestation in a sled dog kennel in the federal state of Brandenburg (Germany Diagnosis and therapy of canine cutaneous dirofilariosis. Tierärztliche Praxis. (2009), 37 (2), 95-101.
Tarello, W. Dermatitis associated with Dirofilaria repens microfilariae in three dogs in Saudi Arabia. Journal of Small Animal Practice. (2003), 44 (3) 132-134.
Keller, et al. Diagnostic approach to microfilaremia. Case report and review of cutanous dirofilariasis.Tierärztliche Praxis. (2007), 35 (1), 31-34.
Mar Pingher; et al. Specific polymerase chain reaction for differential diagnosis of Dirofilaria immitis and Dipetalonema reconditum using primers derived from internal transcribed spacer region 2 (ITS2).Veterinary Parasitology. (2002), 106
(3), 243-252.
Overgaauw, P.;and Dijk, E. van. Autochthonous case of Dirofilaria repens in a dog in the Netherlands. Veterinary Record. (2009), 164 (5), 158.
Seavers A. Cutaneous syndrome possibly caused by heartworm infestation in a dog. Australian Veterinary Journal. (1998), 76(1), 18-20.
Tarello, W. Cutaneous lesions in dogs with Dirofilaria (Nochtiella) repens infestation and concurrent tick-borne transmitted diseases. Veterinary Dermatology. (2002),13 (5), 267-274. Dipetalonema/Acanthocheilonema: Giannetto, S. Dipetalonema dracunculoides (Nematoda: Onchocercidae): first report in dog in Italy. Parasite (2003), 10 (2), 188.
Hargis A M. et al .Dermatitis associated with microfilariae (Filarioidea) in 10 dogs. Veterinary Dermatology. (1999), 10(2), 95-107.
Tarello, W. Identification and treatment of Dipetalonema grassii microfilariae in a cat from central Italy. Veterinary Record. (2004), 155 (18), 565-566.
Dracunculus: Irizarry-Rovira, A. R.; et al. Aspirate of an elbow mass in a Beagle dog. Veterinary Clinical Pathology. (2000), 29 (4129)
Anatrichososma: Hendrix, C. M. et al. Anatrichosoma sp. infection in a dog. Journal of the American Veterinary Medical Association. (1987),191 (8), 984-985.
Jackson, R. K.; Motzel, S. L.; Corrigan, J. E. Diagnostic exercise: cutaneous lesions and unilateral hind limb swelling in a rhesus monkey. Laboratory Animal Science. (1996), 46 (4), 444-447.
Lange, A. L.; Verster, A. Anatrichosoma sp. infestation in the footpads of a cat. South African Journal of Science. (1981), 77 (12), 571.
Marwi, M. A. et al. Anatrichosoma sp. egg and Demodex folliculorum in facial skin scrapings of Orang Aslis. Tropical Biomedicine. (1990), 7 (2), 193-194.
Ramiro-Ibanez F. et al. Ulcerative pododermatitis in a cat associated with Anatrichosoma sp. Journal of Veterinary Diagnostic Investigation. (2002), 14(1), 80-83.
Spirocerca lupi: Balroop-Singh, Juyal P D, Sobti V K. Spirocerca lupi in a subcutaneous nodule in a dog in India. Journal of Veterinary Parasitology. (1999), 13(1): 59-60.
Taenia crassiceps: Ballweber, L. R.
Taenia crassiceps subcutaneous cysticercosis in an adult dog. Veterinary Record. (2009), 165 (23) 693-694.
Bauer, C.; Thiel, W.; Bachmann, R. Taenia crassiceps metacestodes in the subcutis of a dog.Citation disponible uniquement
Metazestoden von Taenia crassiceps in der Unterhaut eines Hundes. Kleintierpraxis. (1998), 43 (1), 37-41.
Beugnet, F. et al. Note à propos d’un cas de cysticercose sous-cutanée chez un chien. Revue de Médecine Vétérinaire. (1996), 147 (3), 227-231.
Bourdeau P. et al .Subcutaneous Taenia crassiceps cysticercosis in a dog with hyper adrenocorticism. Proceedings 14th Annual congress of ESVD-ECVD Pisa Italy. Sept 1997. p186
Chermette R et al. Quelques parasitoses canines exceptionnelles en France. III - Cysticercose proliferative du chien a Taenia crassiceps: a propos de trois cas. Pratique Médicale et Chirurgicale de l’Animal de Compagnie. (1996), 31(2): 125-135.
Klinker, H.; Tintelnot, K.; et al. Taenia crassiceps infection in AIDS.Citation disponible uniquement
Taenia-crassiceps-Infektion bei AIDS. Deutsche Medizinische Wochenschrift (1992), 117 (4), 133-138.
Freeman, R. S et al. Intraocular Taenia crassiceps (Cestoda). Part II. The parasite.American Journal of Tropical Medicine and Hygiene. (1973), 22 (4), 493-495.
Toxocara: Bellanger AP. et al. Comparative assessment of enzyme-linked immunosorbent assay and Western blot for the diagnosis of toxocariasis in patients with skin disorders. Citation disponibleThe British Journal Of Dermatology [Br J
Dermatol]. (2010), 162 (1), pp. 80-2.
Buijs, J. et al. Relationship between allergic manifestations and Toxocara seropositivity: a cross-sectional study among elementary school children. European Respiratory Journal. (1997), 10 (7), 1467-1475.
Gavignet, B.et al. Cutaneous manifestations of human toxocariasis. Journal of the American Academy of Dermatology. (2008), 59 (6),1031-1042.
Sharghi, N. et al. Environmental exposure to Toxocara as a possible risk factor for asthma: a clinic-based case-control study. Clinical Infectious Diseases. (2001), 32 (7). e111-e116.
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Pre-congress symposium
Long term partners
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Réalisation:
Pre-congress symposium
Long term partners
TH
32
Pre-congress symposium
Long term partners