Coprophagia, the practice of eating feces, is a behavior demonstrated by different animals for different reasons. Though beautiful and awe-inspiring, the horse also possesses this behavior. In foals, coprophagia is considered entirely normal and is commonplace. In adult horses, the behavior is seen less frequently, and is only considered normal in small doses. When coprophagia becomes one of your horse's regular activities it may signify several underlying problems that need to be recognized and corrected.
Coprophagia and Foals
So, you're the proud parent of a new foal! Everything he does is cute and wonderful: running, nursing, sleeping … eating manure?! Don't worry, coprophagia is merely another hallmark of normal behavior, however unpleasant it may be.
In the first 1 or 2 months, your foal may be seen eating the fresh manure of his mother. Experts believe that this behavior may have an important purpose to your foal's health. These include:
Improved digestion. Coprophagia is a form of natural inoculation (introduction) of normal bacteria into the gut. These bacteria are necessary for normal digestion, much the way yogurt contains bacteria that aid digestion in humans.
Immunity. These bacteria probably stimulate the immune system to set up a fortress of defenses against common pathogens. Some experts contend that this process extends to parasites, in that coprophagia aids the immune system by exposing your foal to the parasites found in your mare's manure. However, we also know that parasite eggs in fresh feces are not infective (i.e. they do not 'take'), so this issue is less certain. (Regardless, when it comes to the issue of parasites, it's important to have a comprehensive deworming program in place for your mare and foal).
Bonding. There is a possibility that this activity aids in establishing a bond between the mare and foal. There is no proof as yet of this concept.
The unsettling act of coprophagia should taper off by the time your foal reaches 2 months of age, and should completely end at the time of weaning (4 to 5 months).
Coprophagia and Adult Horses
If your adult horse is eating his own manure, or the manure of stable mates, then there's cause for concern. Your horse may be suffering from dietary imbalances, boredom and/or lack of exercise.
Dietary Imbalances. A diet that's too low in protein, fiber or is simply unbalanced is thought to contribute to coprophagia. In this case, your horse is seeking nutrients in the manure that are missing from his diet. Another word for this behavior is pica, which includes the consumption of dirt and other foreign objects. The best way to correct this problem is to review your horse's current diet with your veterinarian and make the recommended changes. Your veterinarian may recommend a different brand of food, a vitamin supplement or a different type or volume of hay.
Boredom. If your horse isn't turned out (exercised) on a regular basis, he'll probably begin to develop unsavory habits, one of which may be coprophagia. Again, this is a behavior that can be changed. Instituting a regular turnout schedule and/or exercise program – along with providing some means of distraction in the stall – can alleviate your horse's boredom and, in turn, bring an end to this unpleasant activity. Distractions include toys (balls), a bigger window, or closer proximity to a friend.
Other Causes. In the older literature, there is discussion about coprophagia linked to various cravings, including trace minerals, salts, and fiber. Again, if this becomes a problem, especially when it involves multiple animals, think about having the diet evaluated by your veterinarian and possibly tested. While coprophagia is an unpleasant subject, we should remember that it's a normal part of the maturation process in your foal. However, with regards to your adult horse, coprophagia indicates that there may be a managerial problem on your farm or homestead, such as inadequate nutrition and insufficient exercise. Of course, your veterinarian is one of the best resources to help identify and correct such problems.