Question
I have a three-year-old Quarter Horse gelding that gets diarrhea on almost all hay except pasture grass. I feed it to him free-choice, but I would like his overall condition to be better. He also gets extremely gassy on alfalfa (lucerne) or orchard grass. How can I improve his condition?
Answer
Hay is dried grass, so it is unusual that a horse can eat grass in pasture and not hay. What types of grasses are found in your pasture? Does this horse get diarrhea when fed hay made from the same types of grasses found in his pasture? If hay made from the same type of grass does not bother the gelding, then avoid the other types of hays that cause problems. If hay made from the same type of grass found in the pasture bothers the horse, then there is a different issue than food sensitivity.
The next area of focus would be on the condition of the gelding’s teeth. Eating hay requires more chewing than eating grass. If the horse has retained caps on the molars, then chewing hay adequately for digestion is difficult. It may be worth the expense of having your veterinarian check this gelding’s teeth to see if there is any issue that might be causing problems with chewing hay.
Have you gone over the horse’s deworming program with your veterinarian? Some horses with heavy parasite burdens have difficulty gaining weight and will have diarrhea. Your veterinarian can advise you on an appropriate deworming program for your area of the country.
Occasional diarrhea has a variety of causes, from abrupt feed or forage changes to nervousness. It is not unusual for a horse to have diarrhea when it is switched from one type of hay to another type of hay, especially if there is a distinct difference in quality (from a stemmy grass to a soft, leafy alfalfa, for example). Assuming the horse has no problems with the changeover, the diarrhea will usually clear up on its own in a couple of days after the microbial population of the hindgut has stabilized.
Chronic diarrhea, on the other hand, is a serious problem and indicates your horse is suffering from a prolonged inability to absorb fluid, perhaps due to mucosal damage.
Has the horse been on any antibiotic treatments or taken supplements that interfere with hindgut microbes? Certain antibiotics have been found to upset the balance of the fiber-digesting bacteria normally found in the hindgut. Use of probiotics would be warranted to bring balance back to the hindgut.
Loss of beneficial bacteria can bring about a precipitous fall in pH, which would further affect the balance of good bacteria. Supplementing with EquiShure, an encapsulated buffer designed to reach the hindgut, would bring the pH back to a normal range where proliferation of beneficial fiber-digesting bacteria could work to rebalance the microbial population.
Damaged mucosa loses its ability to absorb water, which accounts for the high water content of diarrhea. To fix this diarrhea problem, you need to increase absorption and slow the transit time of food through the horse’s gastrointestinal tract. Adding something high in pectin, like beet pulp, has been found to be helpful. Pectins have a high water-holding capacity and are used in dog foods for firming feces. Adding some beet pulp to the diet may help if the problem is chronic diarrhea. If he has chronic diarrhea and it continues, the advice of a veterinarian should be sought.
In regard to adding body condition, you could try feeding a well-formulated concentrate in addition to the forage. A three-year-old is still growing, if only a bit, so it would require nutrients above and beyond those found in pasture grass hay. Because he’s not in optimal condition, he likely also needs the energy a fortified concentrate would provide. Since this horse has an issue with consuming hay, a concentrate high in alternative fibers sources like beet pulp and soy hulls could be a way to get the microbes in the hindgut the essential fiber they need to function correctly. Be sure to read the tag or label, and follow the feeding instructions carefully. Many feeds are meant to be fed at a rate of about 5 to 10 pounds per day; be sure to give your gelding at least the minimum. Because of his sensitive hindgut, I would encourage you to feed concentrate in at least two meals, and three would be preferable. Space out the meals at least four or five hours apart.
