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Piglet diarrhoea don’t let disease score
IDT Biologika GmbH
Am Pharmapark • D-06861 Dessau-Rosslau, Germany
Tel. +49 34901 8850 • www.idt-biologika.de
The piglet’s intestine is the key to sucess
The intestine of a piglet is not just merely a simple
digestion pipe. Each section of the intestinal tract
is dedicated to perform specific and diverse tasks.
A healthy digestive tract, good feed and good
management is the key to maximising the piglet’s
growth and performance. Intestinal diseases which
cause diarrhoea (scouring) during the early stages of
the piglet’s development have an enormous impact
on the animal’s later development and the overall
economics of the farm.
Scouring is the symptom,
but not the problem.
Time is money - each day the piglets are scouring
means another day of reduced profitability.
Today’s piglet producer is not only a farmer, but also a businessman. Optimum levels of productivity can only be reached by running the farm as efficiently as possible. Regular visits from the
vet are important to maintain animal’s health or to restore productivity of the farm through
accurate diagnosis of a problem and speedy implementation of corrective therapy. The common
goal for the farmer and veterinary surgeon’s work being to produce a positive financial result for
the piglet producing unit.
Reduction of hard and soft costs:
Scouring doesn’t necessarily mean that animals die, however a piglet that has suffered from
diarrhoea will be affected in its later development and will hardly ever achieve its full potential
(in particular, weight at weaning, daily weight gain and feed conversion rate etc). These factors
can easily be extrapolated as profit derived from sellable piglets per sow per year. However,
the factors vary markedly depend on the causative agents (see later). Quite often this type of
calculation does not consider so called “soft costs”. Each litter that suffers from diarrhoea has to
be treated by the vet and the farmer in order to minimise the losses. The measures which have
to be taken to address the hard and the soft costs will be addressed in this brochure.
What causes Scouring?
The piglet‘s intestine plays a major
role in disease prevention and healthy growth!
Parasitic
Bacterial
Viral
The causes of scouring are many and varied. Scouring is merely a symptom, but not the final
diagnosis of the problem. The most common causes are infections of certain pathogens, including viruses, bacteria and parasites. The following table gives an overview of the most common
infectious agents in the field of piglet rearing. This brochure does not address factors caused by
management (feeding, stress etc).
*without treatment
Disease
Causative organism
Course of disease
Percentage of
herd affected
Mortality rate*
Incubation period
Rotavirus diarrhoea
Rotavirus
peracute to acute
up to 100%
up to 100%
1–2 Days
TGE
Porcine Coronavirus
peracute to acute
up to 100%
up to 100%
1–4 Days
Vomiting and Wasting Disease
Hemagglutinating Encephalomyelitis-Virus
acute to chronic
up to 10%
10–50%
4–6 Days
Necrotic enteritis
Clostridium perfringens Typ C
peracute to chronic
up to 50%
up to 100%
1–3 Days
Clostridial diarrhoea
Clostridium perfringens Typ A
acute to chronic
up to 50%
10–100%
Less than 1 Day
Coli dysentery
Hemagglutinating E. coli
peracute to chronic
up to 100%
up to 100%
1–3 Days
Coccidiosis
Isospora suis
acute to chronic
up to 100%
up to 50%
2–3 Days
Cryptospirosis
Cryptosporidium parvum
chronic
up to 50%
up to 10%
2–10 Days
Strongyloides
Strongyloides ransomi
acute to chronic
up to 100%
up to 50%
1 Day
Not all organisms are pathogens...
What can be achieved through vaccination?
The digestive tract of a pig is never free of microorganisms. On the contrary! Numerous useful
microorganisms live there (bacteria, fungi, yeasts etc). There are an estimated 100 billion bacteria
in the intestine - this is more than the whole number of body cells in the pig. These microorganisms constitute the microflora, which are useful helpers to cope with life supporting processes
(e.g. provision of nutrients in the gut mucosa, breaking down of feed components). Unlike the
intestine of adult pigs, the young piglet is highly susceptible to disruptions of any kind. The process of birth catapults the piglet from the protective womb, into an environment with completely
different external conditions. While the animal was previously supplied via the umbilical cord
with all necessary nutrients, it now has to organise its own feed intake via the sow’s milk, or any
alternative feed supply provided by the farmer.
Vaccination of very young piglets against scouring is not practical and so the sow vaccination has been developed to provide the piglet passive protection. The sow is vaccinated prior to
farrowing in accordance with the vaccine manufacturer’s instructions. The immune system of
the sow is stimulated to produce certain defensive substances (antibodies) against the proffered
pathogens (antigens) that are contained in the vaccine.
In this early phase of life, the piglet’s intestinal microflora hasn’t established itself completely
and its intestine is forced to adapt rapidly to the new situation described above. Obviously this
sensitive inner balance can be upset by the smallest disturbances.
As mentioned earlier, diarrhoea is merely a symptom. If scouring appears on a farm the very first
step is to identify the causes.
The veterinary surgeon will send samples off for laboratory analysis (e.g. faecal samples), or conduct post mortems on dead animals to identify the causes of the problem. Once these have been
identified, a suitable treatment plan can be established. Here we have to differentiate between
acute therapeutic measures (e.g. antibiotics, electrolyte solutions) and medium to long term
preventative measures (vaccine and/or management changes). It’s self explanatory that the goal
must be to prevent scouring rather than to treat it. This is where vaccination is valuable.
These antibodies will circulate in the blood of the sow and will accumulate in the first milk after
farrowing (colostrum). Colostrum provides the new born piglet with both, essential nutrients as
well as protective antibodies. This explains why it is so important that newborn piglets suckle
without delay. In the first hours of life, the piglet’s intestine has not been fully separated from
its blood stream and during this time extremely small particles (namely the antibodies) can still
pass this barrier and reach the blood stream of the piglet. Other antibodies do not need to pass
this barrier but instead attach to the intestinal wall of the piglet. If the piglet is then confronted
by microorganisms that cause scouring, it has a passive protection against this infection (locally
in the intestine and systemically in the bloodstream) because the attacking pathogens can be
confronted immediately.
The major prerequisites for good immunisation of piglets are:
> Sufficient uptake of colostrum
> High antibody levels in the sow’s milk or colostrum
> Healthy teats of the sow
Most microorganisms in the piglet‘s intestine are
useful and important. But just after birth, the
digestive tract is particularly sensitive to agents
that cause disease. Once scouring occurs, the
farmer needs to involve the vet, identify the cause
of scouring and take corrective measures.
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Bacteria –
“Prevention rather than treatment“
Short information Coli dysentery
> Primary diarrhoea-causing strains are known as ETEC
> Dehydration of the animals can often lead to death
> Protection through sow vaccination possible
Coli Dysentery (Diarrhoea)
Causative agent
More than 1000 different representatives (so called serotypes) are known to date for the
bacterium Escherichia coli (E. coli). Only those that can attach to the gut epithelium and are able
to build toxins at the same time primarily represent the strains that can cause scouring. These
strains are known as enterotoxic E. coli (ETEC).
After ingestion of the E.coli organisms and subsequent passage
through the stomach, the disease complex is characterised by three
phases:
> Rapid multiplication of organisms in the gut
> Adhesion of the organisms to the gut wall
> Release of poisonous substances (enterotoxins)
Clostridium perfringens (C. perfringens) infections
Causative agent
The genus of clostridia contains 82 species, however only those that produce toxins are pathogens. Amongst the clostridial toxins are the strongest known biological poisons (e.g. Botulinum
toxin and Tetanus toxin).
Infection of piglets with clostridia occurs after oral ingestion of the bacteria from the faeces of
the sow. Certain substances in the sow’s milk protect vital antibodies provided via the colostrum
from natural inactivation through digestive processes in the piglet‘s gut. Unfortunately, they
also prevent inactivation of damaging toxins and therefore increase the piglet’s susceptibility
to clostridial toxins. Obviously the problem disappears as soon as the piglets are weaned. In this
context, Clostridium perfringens is the main causative agent of interest.
Course of disease
The toxins are transported into cells of the gut wall where they cause increased release of liquid
into the gut lumen and simultaneously block the absorption of electrolytes by the cells. This
reversion of the natural flow of body liquids, i.e. from the body into the gut, results in the animals
losing large amounts of water and minerals. The intestinal mucosa may not be visibly damaged,
but the process will lead to dehydration of the animals and often to its death.
Following ingestion of C. perfringens Type C, the microorganisms infect the mucosa of the small
intestine and produce toxins. Clostridia produce a poison that not only affects the function of
the intestine, but may also affect and completely destroy the sensitive intestinal tissue and its
deeper mucosal layers (see schematic diagramme below).
Destruction of intestinal tissue through Clostridium perfringens Type C toxins
Common sources of infection are dirty and humid housing, faeces of the sow as well as
excretions of siblings that already suffer from scouring.
Course of disease
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1
toxins
villi
Piglets that appear perfectly healthy may fall ill within the first 12 – 48 hours of life. Usually
the whole litter is affected; the piglets show severe light coloured watery/creamy diarrhoea. The
flanks of the animals become sunken. The piglets are weak and lethargic in the stall. Without
immediate treatment and liquid replacement mortality is very high.
intestinal
cells
outer intestinal layer
defence cells
blood vessel
Treatment
As the infection is attributable to high infection pressure and absence of colostral antibodies, the
introduction of sow vaccination and improvements in hygiene should be considered.
Pre-farrowing vaccination of sows with a vaccine containing the most commonly occurring E.
coli strains is the most effective measure. Modern commercial vaccines that are able to provide
immunisation against cell wall antigens, adhesin antigens and toxins are particularly effective.
Production of an autogenous vaccine is indicated if exotic E. coli strains have been identified
which are not included in commercially available products.
In the acute phase, administration of electrolyte solutions and antibiotics is indicated. Antibiotics
will stop bacteria from multiplying however they are not effective against toxins that are
already present. These measures will help prevent the worsening of the animal’s condition, but
cannot correct the damage which has already taken place and should therefore be restricted to
emergency use only.
Following oral infection, toxins are released into the
intestine.
The toxins damage the sensitive intestinal tissue. Local
inflammation of intestinal tissue occurs as a consequence
of the natural defence reaction of the host.
3
Destruction of intact intestinal tissue
The toxic effect suffices to cause decay of the intestinal
tissue.
From: Sieverding E (2000)
4
red blood cells
Eventually, the damage encroaches on the blood vessels that
nourish the intestine. As a consequence, blood seeps into the
intestinal lumen.
Course of disease (continued)
Table 2: Overview of clinical infection grades with Clostridium perfringens Type A
Three different courses of disease can be seen in a herd:
Acute
Peracute: Sudden death without any typical symptoms of diarrhoea
Acute: The damage to the intestinal mucosa leads to blood entering the intestine. This results in
watery, brown/red bloody granular diarrhoea of the piglet. This clinical picture is called necrotic
enteritis, the general condition is highly disturbed, animals appear depressed and refuse feed, in
some cases vomiting may be observed. Without treatment up to 100% of piglets may die.
Day of life
Chronic: Foamy, bad smelling, grey/yellowish diarrhoea with granular texture may be observed.
Piglets primarily die through water and electrolyte loss than because of the presence of bacterial
toxins.
Table 1: Overview of clinical infection grades with Clostridium perfringens Type C
Acute
Birth to 2nd Day
2nd to 5th Day
5th to 10th (14th) Day
No food intake
Diarrhoea (brown-red)
Diarrhoea (grey-yellow
with gas bubbles)
Circulation problems
Clinical
No diarrhoea
Pathological
findings
(Post mortem)
Bloated piglets due
to blood loss over the
intestine
Dehydration
Dehydration
Runting-stunting
Haemorrhagic to necrotic enteritis
from 1st Day
Diarrhoea
Diarrhoea (yellow, with gas
bubbles)
Dehydration
Potential death of frail piglets or
death in conjunction with mixed
infections (E. coli, rotavirus,
coccidia)
Runting-stunting
Subacute/Chronic
Pathological
findings
(Post mortem)
Day of life
1st to 14th Day
Dehydration
Clinical
Peracute
Subacute/Chronic
Necrotic enteritis
Catarrhal to haemorrhagic
enteritis
Serous to catarrhal enteritis
Treatment
Sows can be vaccinated as a prophylactic measure against C. perfringens Type C with commercially available vaccines, in addition, combination products are marketed that protect piglets
simultaneously against both, dysentery and necrotic enteritis.
In the acute phase, clostridial infections can also be treated with antibiotics. The damage to the
intestine of survivors is irreversible and performance of the animals will be reduced lifelong.
At the moment no licensed vaccine for sows against C. perfringens Type A is available that
would protect piglets from infection. However, autogenous vaccines can be made from pathogens isolated from the affected farm and from which an individually tailored vaccine can be
produced.
The frequency of isolation of certain Clostridium perfringens species has shifted over the past
few years. Towards the end of the 1990s, the predominant species was Type C, nowadays C. perfringens Type A is most frequently isolated. The different Clostridium perfringens species differ
from each other in the type of toxin produced.
In direct comparison, infections caused by C. perfringens Type A result in milder forms of
diarrhoea than those by C. perfringens Type C. In very rare cases piglets will die within 48 hours.
More typically, piglets will develop watery, slimy, yellowish diarrhoea in the first seven days of
life. Toxins from C. perfringens Type A cause liquid exudate from neighbouring cells into the gut
lumen as well as causing inflammation of these cells. Unlike toxins from C. perfringens Type C,
the intestinal tissue will not be completely destroyed.
Hence indirect losses through runting-stunting and reduced daily weight gain are points of
major concern to the piglet producer.
Short information Clostridium perfringens Type C
> Irreversible damage to the lining of the intestine (intestinal mucosa)
> Characteristic bloody diarrhoea
> Protection through sow vaccination possible
Short information Clostridium perfringens Type A
> Milder disease than with C. perfringens Type C
> Indirect losses through runting-stunting
> Protection through sow vaccination possible
Rota- and Corona viruses –
“Ride out the storm”
Rota- and corona viruses are about 100 times smaller than bacteria, are unaffected by antibiotics and to date cannot be prevented by immunising the piglets with a commercially available
vaccine. The only therapy available is to ensure an adequate supply of liquids to prevent the
piglets from dehydrating. Other than that, the only option is to “ride out the storm”.
As the infection spreads through the herd, some animals may survive and subsequently develop
a solid immunity..
Rotavirus
Rotaviruses are not particularly host-adapted and can also cause disease in calves and dogs.
Infections with rotaviruses are considered as multi-factorial diseases. The severity of the disease
will also be determined by housing conditions, hygiene, temperature and the humidity of the
stall. The faeces will appear greasy to fatty and of white to yellowish colour. In healthy pigs, the
mucosa of the intestine is densely covered by minute finger-like structures called “villi” which
increase the surface area of the gut, thus assuring optimal uptake of nutrients from the feed.
During the course of a rotavirus-infection the layer of villi in the small intestine will be completely destroyed. This is accompanied by a rapid and significant loss of liquids and cases of death.
Coronavirus
Another viral intestinal disease is the so-called Transmissible Gastro-Enteritis (TGE), caused by a
coronavirus. As the descriptive name of the problem (TGE) already indicates, the disease is highly
contagious and can affect animals of all ages. If piglets younger than two weeks are affected,
mortality may often reach up to 100%. The disease mainly occurs in winter, as the virus is highly
sensitive to heat and sunlight. Some countries have a surveillance system in place and cases or
suspected cases of TGE have to be notified so the government is in a position to act rapidly to
avoid spreading and to enforce disease control measures.
Parasites –
“Who goes there? Friend or foe?“
Coccidial infection
Causative agent
Scouring can also be caused by parasites. Coccidia are single celled organisms that infect the gut
epithelium. The only commercially important species of coccidia affecting pigs is Isospora suis.
Coccidial infections cause long lasting damage of the gut epithelium, resulting in poor performance and runting-stunting.
Course of disease
Suckling piglets would usually fall ill at 5 to 10 days of age. They would have been infected
immediately after birth through ingestion of so-called oocysts (a specific development stage of
the parasite) from the environment. The parasite invades the intestinal cells and remains there
through several phases of its life-cycle. Finally, a non-sexual multiplication phase occurs after
which the cell “bursts”, releasing vast numbers of the parasites that in turn attack new cells
within the intestinal wall.
The extensive depletion of healthy intestinal cells obviously leads to a serious disruption of feed
absorption and an imbalance of the body’s liquid management. Cells lose water into the gut lumen; consistency of faeces varies from temporarily pasty to profuse, yellowish-watery diarrhoea.
Treatment
Coccidia, like viruses cannot be treated with normal antibiotics, but do respond to orally administered pharmaceuticals given during the first few days of life.
These effectively control coccidiosis in piglets and thus avoid the outbreak of disease.
In pens with suckling piglets, typical disease symptoms are very severe and sudden watery diarrhoea and vomiting. The speed at which the infection spreads, even when animals have no direct
contact to each other is an indication for it’s ability to spread via the air. The important role of
airborne spreading must be kept in mind. The changes in the gut epithelium (villi) is comparable
to those described for a rotavirus infection.
Short information Coccidia
> Settle in the intestinal mucosa
> Litters grow at different rates
> Respond to treatment with pharmaceuticals
Short information Rota- and Coronavirus
> Antibiotics do not work against viruses
> Coronavirus infection is particularly common in winter
> No commercial vaccines available
Short and Sweet – at one glance
Scouring can have various causes and but always means
extra costs, is always time consuming and unnerving. To
develop a suitable strategy to combat and prevent disease,
it is necessary to identify the underlying reason and the
causative agent. This approach enables the piglet producer
and the veterinarian to work together on defining, implementing and executing a specific and tailor-made strategy.
Highly effective vaccines are available to control infectious
diseases. Prevention measures will keep the life stock healthy
and save money in the long term. Ask your veterinarian for
commercial and autogenous vaccines from IDT Biologika GmbH.
Literature References:
Jungnitz, S: Wenn Colis und Co. den Ferkeln zu schaffen machen. In: top agrar, issue 6/1999,
S4 – S7.
e
h
c
Krueger, M, S Schwieger and W Schroedl: Die Magen-Darm-Flora (MDF) des Schweins – ein
Überblick. In: Tieraerztliche Umschau. 63. Jg. 2008, issue 4, 208
s
a
el
Ritzmann, M and K Heinritzi: Durchfallerkrankungen beim Schwein. In: Tieraerztliche Praxis.
2006, issue 34, 411
g
e
l
in
Roesch, H and S Springer: Clostridium perfringens – Infektionen beim Saugferkel. In: Der Praktische Tierarzt. 90. Jg. 2009, issue 1, 78
Rolle, M and A Mayr: Medizinische Mikrobiologie, Infektions- und Seuchenlehre. 8th edition,
Stuttgart 2006, 245
Sieverding, E: Handbuch Gesunde Schweine. 1st edition, Osnabrueck 2000, 192
E
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