The microbiota of any animal refers to the collection of micro-organisms, such as bacteria, viruses, protozoa, and yeast that reside on or in the body of that animal.
Of the myriad diseases that may impact the health of a horse, one of the most difficult to diagnose and successfully treat is that of Equine Protozoal Myeloencephalitis (EPM).
A subject that is currently receiving a great deal of attention both in the U.S. and abroad is that of feed-borne mold and mycotoxins. Mycotoxins are harmful metabolites which are produced by molds (fungi) which exist in the soil and vegetation such as feed, grains and foraging material.
Leaky Gut, a frequently seen condition which may cause a myriad of clinical signs such as behavioral changes, reduced work performance, bone and joint issues, and skin allergies is what is referred to as leaky gut syndrome (LGS). This syndrome occurs when the cells that make up the lining of the intestinal tract are themselves damaged, or the tight junctions which join the cells together break down.
A common condition which is seen in horses is that of hind gut or colonic ulcers (often referred to as Right Dorsal Colitis). Ulcers develop when the mucosal lining of the gastrointestinal tract thins and the microbiome becomes out of balance.
Perhaps the number one digestive issue that comes to the minds of knowledgeable equestrians is that of colic. The most frequently seen causes of colic include high-grain / low-forage containing diets, feed containing mold or other toxins, an abrupt change in diet, dehydration, parasite infection, long-term use of non-steroidal anti-inflammatory drugs, sand ingestion, stress (from training, changes in the environment or climate, etc) dental problems and antibiotic therapy leading to the alteration of the normal microbial population within the gut.
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.
The purpose of the following article is to provide an overview of the equine intestinal tract, including its anatomy, how it functions in a healthy state, the most commonly seen intestinal diseases, clinical signs of these illnesses, as well as therapeutic options to address the illnesses. Finally, preventative measures which can be used through proper diet and husbandry practices will conclude this article.
Over the course of time, man’s domestication of the horse has resulted in many alterations of its natural behaviors. In particular, the contents and frequency of the equine diet have been adjusted to make their care more convenient for humans.
Not including wolf teeth, mature female horses have anywhere from 36 to 40 teeth, while males generally have 40 teeth. The equine teeth are divided into two sections within the oral cavity—the incisors which are seen at the front of the mouth, and the cheek teeth which are made up of molars and premolars.
After a horse has ingested a mouthful of food, the circular chewing motion is used to grind up the food into smaller particles which will then be mixed with saliva, forming a bolus. The bolus is then pushed to the back of the pharynx, where it is swallowed and passed into the esophagus.
