Page 779 - The Veterinary Care of the Horse

When to call the vet

Diarrhoea is a sign of many conditions. It may be the consequence of a dietary change and
VetBooks.ir last for a couple of days or it may indicate that something is seriously wrong. The following

guidelines are offered.
• If the horse is off colour or has a temperature, the vet should be called immediately.

• Foals with diarrhoea should also be examined by the vet urgently. The exception is the

mild self–limiting diarrhoea seen in a foal when it is about 10 days old. This is foal-heat
diarrhoea associated with the mare coming into season.

• If the horse seems fine in itself but has loose droppings for more than a day or two, it
should be checked over by the vet.

Diarrhoea due to dietary changes is usually short-lived and requires sensible management

rather than veterinary treatment. However, diarrhoea caused by Salmonella spp. or Clostridia
spp. infections may be severe and debilitating and is potentially fatal. The absorption of

bacterial endotoxins leads to severe clinical signs and affected horses need urgent and
intensive treatment.

Caution

Salmonella is a zoonosis which means it can be transmitted to humans. Up to 20%

of horses carry the bacterium without showing any clinical signs and only excrete
it during times of stress. Your vet will decide if the Salmonella is the cause of the
diarrhoea or whether it is being excreted due to the stress of another illness.

Salmonella spp. may be cultured from a horse with diarrhoea but there is often
another underlying cause. All animals shedding Salmonella should be isolated

from other horses as they are a potential source of infection. Overalls and
disposable gloves should be worn when dealing with infected horses and great care
must be taken not to accidentally ingest the microorganism. Your vet will advise

you on suitable disinfectants and hygiene precautions.

Diagnosis

The first step with either acute or chronic diarrhoea is to try to find the cause through clinical
examination and discussion of the history. A dental examination is likely to be performed.

The vet may take: