There are a large number of disorders that can impact the equine intestinal tract, all with corresponding clinical signs which can be subtle or quite dramatic. These clinical signs include diarrhea, constipation or a decrease in fecal production, reduced appetite, blood in the feces, abdominal pain and bloating, dehydration, shock, straining to defecate, and poor performance.
Diarrhea In Horses
Diarrhea is a condition defined as loose or excessive/ too-frequent defecation which occurs when the intestine fails to properly absorb electrolytes, protein, and water. This failure is due to damage to the intestinal lining which normally serves to absorb certain essential nutrients as well as acting as a barrier against the absorption of other undesirable elements. The body responds by rapidly excreting the intestinal contents in an attempt to rid itself of any pathogenic or toxic substance if there is one present.
Diarrhea in horses can be an acute or chronic condition which is caused by a variety of ailments. In some cases, the cause can be as simple as changes in feed, over-exposure to rich grass, ingestion of large quantities of sand, or mold or other toxins in the feed. There are numerous other possible etiologies including parasites, viral or bacterial infections. In addition, severe inflammation, cancer in the intestinal tract, certain inherited disorders and abnormal pancreatic secretions can lead to malabsorption, which in turn can result in dehydration and electrolyte imbalance, and in severe cases, shock.
Any time a significant change is detected in the consistency, color, volume, or frequency of bowel movements, a veterinarian should be consulted and the horse and its feces should be thoroughly examined. Additional lab work and diagnostic tests should be performed as indicated in each case. The affected horse should be isolated from the remainder of the herd in order to prevent the possible spread of any infection to other animals, especially those that are young or aged and may not have fully functioning immune systems. No equipment should be shared between sick and healthy animals.
No matter what the etiology of the diarrhea is, the initial step in treatment must be supportive care, including intravenous fluids to help resolve dehydration, protein replacement in the form of plasma, and administration of electrolytes as indicated to correct any imbalances. Once the horse is stabilized, the next step is to remove any bad bacteria and/or toxins and to reestablish good gut flora. There are a variety of products available which act by binding to bacteria or toxins while helping to reduce fluid loss. Your veterinarian will also recommend appropriate probiotic products to aid in the reestablishment of the good bacteria.
Treating the underlying cause of the diarrhea is essential--if the cause is parasitic, then appropriate anti-parasitic protocol must be followed. If the cause is bacterial in nature, then it must be determined which bacteria are present, and whether or not antibiotics are indicated. In certain situations, the addition of antibiotics to the horse’s system may cause a worsening of the diarrhea by removing additional good bacteria from the gut which in turn will lead to an even greater decrease in food and fluid absorption. If the cause of diarrhea is not tied to an infection or dietary related, than further steps must be taken to determine what the underlying issue is, and what appropriate actions must be taken to remedy the situation.
Time is of the essence in cases of diarrhea. If the cause is not quickly identified and the horse is not stabilized, then a cascade effect impacting other body systems can result, including septicemia, laminitis, and even blood clot formation.
Coming up next in this ImmuBiome gastrointestinal series is an overview of equine colic.
Mycotoxins (which will be discussed further in future articles) Mold in hay or grain can be a big factor in contributing to diarrhea as well. The body responds by liquefying to purge the body of the pathogen as quickly as possible.
Experts increasingly believe that these digestive aids – namely prebiotics and probiotics - can restore the microbial community in the horse’s gut to a stable and healthy state.
Every horse owner’s idea of paradise is to see their horse grazing on a lush green field; however, there are a number of serious issues that should be considered prior to allowing grazing on rich grass.