Colitis in Horses
What is Colitis in horses?The word “colitis” describes a part of the body (“col” for colon) and how it is affected (“itis” for inflammation). It does not refer to a particular disease, the type of colitis, or its cause. Frequent, loose stools or diarrhea is one of the most common signs of colitis, although there may be other signs such as colic, fever, or weight loss depending on the cause.
Types and Causes of Equine Colitis
Colitis in adult horses can be divided into two main types: infectious and non-infectious.
Infectious causes include:
- Bacterial infections such as from Salmonella, Clostridium, or Potomac Horse Fever
- Viral infections such as Equine Coronavirus
- Parasitic infections (generally due to small strongyles
- NSAIDs (non-steroidal anti-inflammatory drugs)
- Sudden feed changes
- Stress related to trailering, competition, exercise or management changes, illness, etc.
- Inflammatory Bowel Disease or IBD
- Sand ingestion
- Gastrointestinal lymphoma, a type of cancer of white blood cells
One type of colitis, Right Dorsal Colitis or RDC, occurs in a specific segment of the colon, called the right dorsal colon. Also known as colonic ulcers, RDC has been linked to particularly high doses of NSAIDs or a reaction to an appropriate dose. Involving ulcers of the colon lining and not just inflammation, signs in addition to diarrhea include recurring colic, weight loss, a reluctance to eat, lack of energy, fever, and edema. Because the treatment and management of RDC is slightly different than that of a more general colitis, it is important to have a veterinary diagnosis first.
If your horse has diarrhea or even manure that’s more “cow plop” in consistency, like the manure pictured here, it's a smart idea to touch base with your vet about what you're seeing.
Signs and Symptoms
- Treat the underlying cause if known (infection, parasites, medication, etc). In some cases, this may mean simply controlling the diarrhea through the use of intestinal protectants such as bismuth, kaolin, pectin, charcoal, smectite clay, or the yeast Saccharomyces boulardii. Some of these agents also have the ability to prevent bacteria from “sticking” to and damaging colon cells or to bind toxins, in particular the endotoxins released by bacteria that can leak into the bloodstream (endotoxemia).
- Replace lost fluids, electrolytes, and protein. If the physical exam or bloodwork shows the horse is dehydrated or has lost significant amounts of electrolytes and protein, it may be necessary to insert an intravenous (IV) catheter into the jugular vein of the neck and provide IV fluids. Depending on how sick the horse is as well as the degree of fluid and electrolyte loss, this may be a one-time treatment, may be spread over 24 hours, or may need to be given continuously for several days, requiring hospitalization and repeated monitoring of vital signs and bloodwork.
- Address pain, inflammation, and endotoxemia. Some horses with colitis also experience abdominal pain, or colic, which should be controlled both for their comfort and to reduce additional stress. It is also important to manage the inflammation associated with colitis and to prevent endotoxemia, which can lead to further complications. Because some of the medications used to address pain, inflammation, and endotoxemia are the same ones known to cause colitis in the first place, great care must be taken in selecting appropriate drugs and dosages
- Repair intestinal tissue and restore microflora balance. As the horse is kept hydrated and attempts are made to prevent the colitis from getting worse, it is also important to begin restoring the colon to normal health and function. This includes providing the building blocks of the cells that line the colon as well as the live, beneficial microorganisms (probiotics) and their preferred food source (prebiotics). The amino acid glutamine is recognized for its role in the renewal of healthy intestinal lining, including restoring immune function to the GI tract. Certain species and strains of bacteria, yeast, and protozoa are helpful when re-establishing the normal gut microflora as are soluble fibers such as psyllium, MOS, FOS, inulin, and others.
- Laminitis (inflammation of the lamina inside the hooves)
- Thrombosis (a blood clot) and other coagulation issues
- Circulatory shock because of low blood volume and the presence of endotoxins in the blood
- Secondary infections such as pneumonia and at the site of IV catheter placement
In severe cases, laminitis can lead to separation of the lamina from the hoof wall, visible in this x-ray as a rotated coffin bone.
Part of veterinary monitoring colitis cases involves observing for early signs of any of these complications and sometimes even taking measures (such as icing the feet or administering medications) to prevent their development.
Barn supplies like pitchforks shouldn't be shared between the horse suspected of colitis and the other horses in the barn
Is Colitis contagious?
Allow horses recovering from a serious bout of colitis plenty of downtime to regain their weight and fitness.
Preventing Colitis in Horses
- Antibiotics – only give antibiotics to horses under the direction of a veterinarian
- NSAIDs (non-steroidal anti-inflammatory drugs) – try to limit the use (dosage and frequency) of non-steroidal drugs such as bute, Banamine, and others, especially in horses with a history of RDC
- Sudden feed changes – make adjustments to the diet, both hay and grain, gradually, over at least 7 to 10 days
- Stress related to trailering, competition, exercise or management changes, illness, etc. – as much as possible, try to keep the same schedule and diet with horses while travelling, and allow time for rest and recover after transport and events
- Sand ingestion –avoid feeding horses where they could pick up sand with their food, and consider a monthly purge with a psyllium-based product
SmartPak strongly encourages you to consult your veterinarian regarding specific questions about your horse's health. This information is not intended to diagnose or treat any disease, and is purely educational.