Page 1384 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

The foal 1359

VetBooks.ir 14.25 immunosorbent assays (ELISAs), Salmonella poly-
merase chain reaction (PCR), viral quantitative (q)
PCR/PCR/ELISAs, Cryptosporidium ELISA, para-
sitological examination and direct microscopy. It is
important to collect adequate quantities of faecal
material and place them in sterile containers.
In most diarrhoeic foals, but particularly those
with severe clinical signs or chronic cases, blood sam-
ples are indicated. Samples for blood culture should
be taken from all young foals with diarrhoea and
signs of SIRS or sepsis. Assessment of blood samples
for haematology, lactate, serum electrolytes, serum
proteins, inflammatory markers and renal enzymes
is useful for both diagnosis and directing therapy.
PCV, lactate and total protein levels may help with
Fig. 14.25 Haemorrhagic diarrhoea in a foal with assessment of the foal’s volume status, perfusion and
clostridiosis. hydration, in addition to reliable clinical indicators
such as mentation, urine output, peripheral pulse
quality, heart rate and extremity temperature. The
pain may be anorexic. Other foals may present with total and differential WBC count will vary with the
severe colic that mimics a surgical lesion. The signs type of enteric infection, often showing dramatic
of abdominal pain sometimes precede the onset of decreases in foals with sepsis caused by Salmonella
diarrhoea. Foals can become rapidly dehydrated and spp. and Clostridia spp. Blood glucose concentrations
suffer significant electrolyte imbalances when the may be abnormal depending on the severity of dis-
diarrhoea is watery and of high volume. In addition, ease. Sepsis scoring can be beneficial. Electrolyte
their reduction in milk consumption contributes to concentrations and acid–base status are more dif-
decreases in total body water. Pyrexia, depression, ficult to ascertain in the general practice situation,
SIRS, sepsis and circulatory collapse can occur rapidly but when available are very useful in developing a
in foals with some of the bacterial diarrhoea-causing rational treatment plan. All of the major electro-
pathogens. Severe bacterial enteritis with septic shock lytes (sodium, potassium, chloride, calcium) may
can rapidly lead to acute kidney injury, therefore renal be reduced and there may be a metabolic acidosis.
function should be monitored closely by assessment Repeated samples to indicate trends or responses are
of urine output/parameters and renal enzymes. There particularly useful.
may be a period of 12–18 hours before the foal devel-
ops diarrhoea and when it shows colic-like signs, and Management
this is a particular feature of rotavirus infections. Treatment should be instituted as soon as possible,
Gastroduodenal ulcers are a complication of diar- usually before the results of diagnostic tests are
rhoea, particularly in rotavirus infections. available. This is especially important in the infec-
tious forms of disease, which can rapidly become
Diagnosis life-threatening. Treatment in many cases of diar-
It is possible to make a specific diagnosis in only rhoea is similar, with supportive care and detailed
about 50% of cases but attempts should always be nursing playing a large part in a successful outcome.
made to achieve this owing to the contagious nature
of the more common causes (e.g. rotavirus). In Fluid therapy
many cases it is appropriate to take fresh faecal sam- Adequate appropriate fluid therapy is the key to suc-
ples for virology testing, bacteriology culture and cessful treatment. When it is necessary to give fluids,
sensitivity testing, clostridial toxin enzyme-linked consideration should be given to the most appropriate