What is coprophagia?

Coprophagia, the practice of eating faeces or ‘droppings’, is a behaviour demonstrated by different animals for different reasons. Mature healthy horses normally have no physiological drive to consume faeces. In foals, coprophagia is common and is considered normal. In adult horses, the behaviour is seen less frequently.

When coprophagia becomes one of a horse's regular activities, it may signify several underlying problems that need to be identified and corrected.

Coprophagia is almost invariably seen in stabled horses and rarely occurs where horses are kept mainly out at pasture.

If an adult horse eats its own manure and the manure of stable companions, then there is cause for concern.

What causes coprophagia?

There are several likely causes of coprophagia in adult horses, including the following:

  • Dietary imbalances: Dietary Imbalances may be implicated in some cases. A diet that's too low in protein, energy, fibre, or is unbalanced, is thought to contribute to coprophagia. In this case, the horse is seeking nutrients in the manure that are missing from his diet. Another word for this behaviour is ‘pica’, which includes the consumption of dirt and other foreign objects.
  • Boredom: Manure eating in horses can also be caused by boredom or social disorder (e.g. isolation, incompatible company, frequent changes in the horse’s turnout routine or companions). If a horse isn't turned out (exercised) on a regular basis, he is likely to begin to develop undesirable habits such as coprophagia. People and animals do all sorts of strange things when they get "cabin fever" and for a horse, coprophagia could be an activity to just pass the time.
  • Comfort food: In older horses, eating manure could start out as an innocent experiment, perhaps an attraction to warm faeces which might appear like a mash, a comforting meal. This is particularly so in the case of a horse that is underweight and manure could be taken to serve as another feed source.
  • Salt and minerals: Other causes include a link between coprophagia and various cravings, including trace minerals, salts, and fibre. A mineral block serves a good purpose here. Access to a salt lick is also recommended as some horses may need/crave more salt than they get in a mineral block.
  • Water: Where a horse’s water needs are not adequately met, there is a slight possibility that it may be attracted to faeces because of its high moisture content.
  • Recycling of feed particles in manure: This is based on a well-acknowledged theory which has a certain element of credibility. Where oats that are not completely crushed are fed in the diet, droppings may be eaten. Whole oats are not digested by the horse so are passed in the droppings. The intact grains that are passed in the droppings can give rise to a horse ‘picking’ at its droppings.
  • Coarse ration: Horses fed coarse ration (which has a certain amount of molasses in it) can develop coprophagia; the molasses is similar to treacle and may sweeten the droppings, which can give a horse an incentive to nibble at them after passing its faeces.
  • Does coprophagia occur in other animals?

    Coprophagia is normal routine practice in rabbits. In this case, coprophagia is a nutritionally necessary behaviour for the rabbit, a species whose intestinal tract is very similar to that of the horse.

    Rabbits make effective use of valuable nutrients passed in their faeces by ingesting manure for a second pass. The natural nutrients lost in their manure are released or produced by the normal gut process of microbial breakdown of dietary fibre, which are a rich source of proteins, lipids, vitamins, etc. It has been suggested that perhaps some horses who eat manure are doing a similar thing, particularly if they are on a very restricted diet because they need to lose weight.

    What quantities of droppings do coprophagic horses consume?

    Initially the animal may just take in very small quantities which are nibbled occasionally but this may also progress to a more extreme level where the horse consumes almost all of the droppings that it passes each day.