26
PARASITES
VP NOVEMBER 2016
PLENTY OF PARASITES – TOO MANY
TO CHOOSE FROM?
WITH A PLETHORA OF
According to a recent survey, Ixodes
PARASITES TO CONSIDER,
ricinus (Figure 1) was found to be the
how do you pick your parasite of
most commonly identified tick in the
importance? Climate change, increased UK, with 89% of ticks found on dogs
human
belonging
and pet
to this
BLAISE SCOTT-MORRIS
travel,
species
of Virbac looks at the most
relaxed
(The
recent research and reminds
entry
Big Tick
veterinary surgeons not
laws
Project,
to forget our old familiar
for pets
2016).
friends among the vast array
into the
Only
of parasites now confronting us in practice
UK …
0.17% of
these are
the ticks
some of the many reasons that have
recovered from dogs were identified as
been mentioned whilst discussing if,
Dermacentor reticulatus.
how and when the parasite and disease
It would seem that despite recently
profile of the UK will change.
diagnosed cases of babesiosis in Essex,
Angiostongylus vasorum (lungworm)
transmitted by D. reticulatus (Figure
was first identified in the UK in 1979
2), this tick is still rare in the UK and,
in Cornwall, infecting dogs, red foxes
although it is always prudent to be
and other carnivores (Jones, 1980).
vigilant, Ixodes is still the most common
Since then, spread of A. vasorum has
genus of tick in the UK.
been documented within the UK and
SAVSNET, based at the University
Europe.
of Liverpool, has not reported any
Initially the focus of spread was
new babesiosis cases since these initial
within the south of the UK; however,
reports. This indicates that the cases
more recent studies have identified foci were due to locally infected ticks
of infection in Northern England and
and it is most likely under control
Scotland.
(SAVSNET, 2016).
Data from 2005-06 showed a UK
When your clients are travelling
prevalence of 7.3% in foxes with large
abroad with their pets it is necessary to
regional variations and no A. vasorum
adjust advice and treatment plans with
detected in foxes in northern England
regards to ticks – we don’t want them
or Scotland (Morgan, 2008). However,
returning with any unwanted visitors!
in 2013-14, overall UK prevalence
In Europe, the brown dog tick,
in foxes had risen to 18.3%, with
Rhipicephalus sanguineus, is also of
prevalence in all regions significantly
importance, especially as it can live
higher than the previous survey
indoors and so there is potential for
(Taylor, 2015).
it to survive in our heated homes in
Of particular importance is the
the UK. Remember that repellency
appearance of A. vasorum
is the most effective
in northern England,
method to decrease
where it had not been
disease transmission
detected before (Taylor,
(Schunack, 2015). There
2015). Although there
are currently no tick
can be limitations to
treatment or repellency
prevalence studies,
requirements advised
general trends indicate
by DEFRA under the
spread and increased
PETS travel scheme, but
awareness.
owners should be made
aware of the risks when
Ticks in pockets
travelling and given
Historically, ticks in
appropriate medication.
Figure 2. Dermacentor
the UK have been
One ectoparasite
reticulatus.
predominantly found in
that we should never
pockets such as the south-west and
forget about is the flea. A resourceful
Wales. However, across the UK ticks
devil that can be the cause of many
are becoming more prominent due to
headaches for both vets and clients,
warmer winters and wetter summers.
there are some important aspects of
Blaise Scott-Morris, BVSc, MRCVS, qualified at Bristol in 2011. For
three and a half years Blaise worked in small animal practice for both
independent and corporate practices, developing a keen interest in
client communication and practice profitability. In October 2014,
Blaise joined Virbac as a veterinary adviser, providing technical
support and training, both internally and externally, and participating
in pharmacovigilance.
parasites we encounter
the lifecycle that can be
in the UK when deciding
used to help tackle an
upon a treatment
infestation (see Figure
regime for your practice.
3).
Individuals may have
Although it is vital
differing requirements
to use an on-animal
depending upon their
treatment for cats and
lifestyle and travel
dogs, adult fleas only
pattern, i.e. are they
represent about 5% of
going to a known tick
the whole lifecycle, so it
area or travelling abroad?
is important to ensure
By keeping up to
the environment is also
Figure 1. A male Ixodes date with the current
treated. Nothing but
ricinus tick.
information on parasite
fire can kill the pupal
and disease prevalence, we can keep
stage but advising owners to vacuum
our parasite advice as relevant as
regularly after using an environmental
possible.
treatment can encourage the pupae to
emerge as young adult fleas and speed
References
up resolution of the infestation.
Jones, G. W., Neal, C. and Turner, G. R.
Don’t forget that it is not just
(1980) Angiostrongylus vasorum infection
the repulsion and bites that owners
experience with fleas or the discomfort in dogs in Cornwall. Veterinary Record
106: 83.
for their pets: fleas can also transmit
Morgan, E. R., Tomlinson, A., Hunter,
disease. They act as the intermediate
S., Nichols, T., Roberts, E., Fox, M. T.
host for Dipylidium caninum so it is
and Taylor, M. A. (2008) Angiostrongylus
important to treat concurrently for
vasorum and Eucoleus aerophilus in
tapeworm when you are treating a flea
foxes (Vulpes vulpes) in Great Britain.
infestation.
Veterinary Parasitology 154: 48-57.
Preventive action
SAVSNET (2016) https://www.
In the long run, as the old saying
liverpool.ac.uk/savsnet/.
goes, “prevention is better than cure”
Schunack, E. H. and Fourrie, J. J.
so ensure your clients are not only
(2015) Comparative efficacy of topical
compliant but also administering
applied permethrin/imidacloprid and
treatments correctly. Providing
oral administration of ofoxolaner
environmental protection as a
or fluralaner against transmission of
preventive action, such as with Indorex Ehrlichia canis by infected Rhipicephalus
(Virbac) which has action against the
sanguineus to dogs. Proceedings
developing eggs and larvae for up
WAAVP.
to 12 months, can be invaluable in
Taylor, C. S., Garcia Gato, R.,
preventing flea infestations.
Learmount, J., Aziz, N.A. et al (2015)
We are all aware of the endoparasites Increased prevalence and geographic
that we need to consider when treating spread of the cardiopulmonary
pets in the UK, and it is beyond the
nematode Angiostrongylus vasorum in fox
scope of this article to discuss the
populations in Great Britain. Parasitology
exhaustive list. However, one which
142 (9): 1,190-1,195.
is worth highlighting is Echinococcus
The Big Tick Project (2016) MSD
multilocularis. It’s not a parasite we
Animal Health: www.bigtickproject.
currently have in the UK but certainly
co.uk.
one we want to avoid, due to its
Umhang, G., Comte, S., Hormaz, V.,
zoonotic potential.
Boucher, J.M., Raton, V. et al (2016)
Alveolar echinococcosis is
Retrospective analyses of fox feces by
considered to be one of the most
real time PCR to identify new endemic
serious zoonoses in the Northern
areas of Echinococcus multilocularis in
Hemisphere (Umhang, 2016). E.
France. Parasitology Research August.
multilocularis has spread across Europe
in recent decades: its lifecycle relies
upon predator-prey interactions such
as foxes and small rodents (Umhang,
2016).
Data from fox faeces in France show
the parasite is expanding its prevalence,
identifying a need for surveillance
but also continued treatment of dogs
before re-entry into the UK (Umhang,
2016).
Despite discussing the risks from
Europe and changing parasite and
disease patterns in the UK, it is also
Figure 3. The flea lifecycle.
important not to forget the common