My horse likes to eat manure. What's going on here?
Ah - this behavior, called coprophagia, is one of those things that can make your skin crawl. I get a case of the heebie jeebies just thinking about it! Current research tells us that there are many possible reasons for this - but no concrete answers about why.
Some of the guesses as to why horses eat manure include: boredom and stress, dietary insufficiency, lack of "chewing time", antibiotic use (antibiotics can adjust the natural gut microbes), and lack of exercise. There seems to be no conclusive evidence as to pinpoint a certain cause.
There is also a condition called Pica - which is when horses eat non-food items, such as wood, dirt, twigs, bark, etc. The cause of this is also unknown, but recent studies suggest that an iron or copper deficiency plays a part.
Coprophagia is seen as normal in foals starting at about two to three weeks old. Again - who really knows why!!
What can you do? First, consult with your Veterinarian and/or Equine Nutritionist to rule out medical issues. You can also offer more hay, exercise, and toys. Slow feeders are a great way to curb boredom if you suspect your horse needs more stimulation. Some of us are also wondering how to deal with the "bad breath". Since we can't floss our horses, that limits our options. You could use a large syringe (30 cc or larger) to flush out your horse's mouth with water before bitting and riding.
You can also wage war on your horse's boredom and destructive tendencies by following some of the tips for stall rest and for battling a destructive horse. You should be more worried about pica than coprophagia, since eating wood and foreign objects is much like a puppy eating shoes. Bad for the objects, and may require major medical intervention for the horse. In that case, it's your job to pica-proof your horse's living quarters. Fences are a very common target, in which case I really like hot wire/electric fencing.
What have your experiences been?