Diarrhea in Horses
If the diarrhea isn’t caused by something obvious that you know will pass (such as a minor behavioral cause), it’s time to discover what else could be causing it. Start to worry if, along with watery manure, your horse shows other symptoms, including:
- Blood or mucus in the manure
- Foul-smelling manure (beyond the normal manure smell)
- Diarrhea that lasts more than 24 hours
- “Projectile pooping”
- Other symptoms of colic
- Elevated rectal temperature
- Lethargy
- Signs of weight loss or other health problems before the diarrhea started
- Signs of dehydration (do a skin pinch or capillary refill test)
- Pale gums
- Lack of appetite
Treatment & Prevention
If your horse has diarrhea, you need to determine how severe it is. You may know that your horse gets nervous when the farrier comes, in the trailer, or at horse shows. In these cases, runny manure probably isn’t a sign of illness and once the stress is over, things will return to normal. Do make sure your horse is eating and drinking normally otherwise. If after 24 hours, the diarrhea is not gone, call the vet, who will help you find out what's causing the diarrhea and start your horse on the appropriate treatment.
The vet may take a fecal sample and/or blood sample to help determine the cause of the problem and suggest keeping the horse away from other horses, in case the cause is contagious. The vet may also give the horse medication to ease any abdominal discomfort and to help slow the gut down. Probiotics and other gut-balancing supplements may be given on the advice of your veterinarian. Depending on what caused the diarrhea, your horse might be given antibiotics or other medications.
Avoiding diarrhea is very much like avoiding colic. It's hard to entirely prevent it, but smart preventive measures will help:
- Avoid rapid changes to new feeds.1
- Introduce horses to lush pastures gradually.
- Keep feeds, such as grains and concentrated food, locked down so horses that might get loose can’t help themselves.
- Vaccinate your horse with the core vaccines and any others that are appropriate for your area.