Skip to content
Search Library
thumbnail

Horses frequently bite each other when they are playing, and occasionally nip at their own legs or flanks to chase away flies or to signal discomfort from colic. When a horse repeatedly nips or bites himself, often to the point of drawing blood, this behavior is known as self-mutilation. It is far more common in males than in females and is most prevalent in stallions.

In a typical pattern for developing the habit of self-mutilation, a colt may begin to nip at his chest or flanks when he is about two years old, a time when sexual maturity is progressing. Horses that exhibit this behavior virtually always start it before the age of four. The first instances are milder, simply showing as disturbed patches in the coat, but may progress to bites that break the skin and produce persistent wounds. Horses may spin around, kick, or buck as part of the behavior pattern. In extreme cases, they can destroy their blankets, run into fences or stall walls, or throw themselves violently onto the ground.

Discomfort of any type can cause horses to nip at their sides, so horses showing any of these behaviors should be observed for colic or another health issue. An examination by a veterinarian can sometimes uncover a source of pain in the horse’s digestive or musculoskeletal systems. In males, pain might be caused by a twisted testicular cord or a urethral tear, and any horse might be suffering from the discomfort of gastric or colonic ulcers. However, it is not uncommon to find no specific cause related to pain.

In older colts and stallions, self-mutilation is believed to be linked to sexual traits. Mature stallions that meet other stallions usually smell each other’s flanks and then squeal, kick, rear, strike, and bite, and it is possible that self-mutilation is an expression of this behavior that is triggered by smelling certain odors. Surprisingly, gelding affected stallions doesn’t always stop the behavior, and there are reports of newly castrated males beginning self-mutilation soon after gelding.

Ruling out pain is the first step in attempting to stop self-mutilation. A veterinarian should be asked to conduct a full examination of the horse, treating any conditions that could be causing even mild discomfort. Eliminating pain is effective in stopping self-mutilation in some horses. Physical restraints such as a rigid neck cradle might keep the horse from biting its flanks, but this type of treatment often results in the animal beginning other stereotypies such as cribbing or weaving. Providing more turnout time, pasturing the horse with one or two congenial buddies, increasing work or exercise, and adding a stall-mate such as a goat or chicken have helped some affected horses. Response to tranquilizers and other calming medications has been varied.

Feed management solutions that are sometimes effective are feeding less grain, providing free-choice hay, and using a slow-feeder haynet so the horse must spend more time picking out small bites rather than gobbling the hay quickly and then having many hours with nothing to do. Feeding a hindgut buffer may sooth the horse if the cause is due to discomfort in the digestive tract. A combination of several management steps might offer the best chance of eliminating self-mutilation behavior.

X

Subscribe to Equinews and get the latest equine nutrition and health news delivered to your inbox. Sign up for free now!