Nutritional deficiency and tail chewing?

Q. Dear Dr. Gray – I have about 15 young horses (a mix of weanlings and yearlings) turned out together. They have a large turnout area, but there isn’t much grass, so we provide them with free choice hay from a hay bunker (an alfalfa/grass mix). They also receive fortified grain and have access to salt/mineral blocks. We’ve been breeding horses for many years, and for some reason over the past year we’ve started to have a problem with some of these young horses chewing each other’s tails off. I’m wondering if you guys know of a correlation between a nutritional deficiency or a health issue and tail chewing, or if it is more likely boredom/normal behavior for young horses.

Thank you! – LH, Texas

A. Dear LH,

This can sure be a frustrating problem. Unfortunately, the research I found showed mixed results about the cause of this behavior in young horses. Most agree that lack of roughage plays a role, but they leave the door open for other causes such as nutritional deficiencies (lack of protein or certain minerals), boredom, curiosity, playfulness, teething and others. Because chewing is necessary to stimulate the production of saliva, there may even be a chance that gastric (stomach) irritation has something to do with this undesirable habit.

Tail chewing (hair eating or trichophagia) is undesirable for a couple of reasons. First, it does nothing for the appearance of the horse being nibbled on! Short, ragged tails do not win points in the show ring or earn dollars at sales. Second, hair is a rather indigestible substance, and eating it can lead to the development of hairballs in the large intestine, removable only via surgery. So what can be done to break this potentially harmful habit?

Step number one is identifying the culprit(s). While isolating a young horse probably isn’t ideal, maybe splitting up the herd into several smaller groups will provide the tail chewer(s) with more opportunities at the feed bunk as well as more room to run and play. At the very least you’ll be limiting the number of ragged, chopped off tails. Hint: the chewer probably has the longest, nicest tail of the group.

Next, consider your hay quality and quantity. Could you provide it in some type of slow hay feeder that keeps them chewing longer and makes foraging a game? Since your pasture is limited and natural grazing restricted, offering hay in a way that makes them work for it, while limiting them to one bite at a time, may help meet the fundamental urge of horses to chew. If boredom is the issue, try adding toys to their paddock like small balls with handles they can pick up or large balls they can push and roll. Food toys that provide a treat if manipulated properly are another option.

Finally, you may have to initially discourage the tail chewer by applying a nasty-tasting substance to the other horses’ tails (another reason why a smaller group might be a good idea). Rather than the cayenne pepper stuck on petroleum jelly approach—which may cause other problems if it gets in eyes, on noses or touches other sensitive areas—just use good ol’ horse shampoo or conditioner. While these products may smell good and make horses look good, they sure don’t taste good, and horses with a tendency to chew hair will soon figure this out.

I hope you quickly unmask the offender and that one of these techniques turns him off eating tail hair for good!