What Causes Equine Self-Mutilation Syndrome?
There is good evidence to suggest that equine self-mutilation syndrome, or at least an element of sensitivity to stressors, may be hereditary. The behaviours themselves may have developed in direct respone to some combination of sexual frustration, inactivity and stall confinement, and may simply be a re-directed expression of male aggressive tendencies. Male dominance ritual aggression, for example, is expressed as biting at other horses’ necks and limbs; however, in the absence of other horses, this behaviour may be self-directed by biting at one’s own neck instead. Hormones may play a role in triggering or in sustaining stereotypic behaviours. For example, pleasure centres in the brain may be stimulated, which could reinforce the behaviour. Also, hormones which deaden the horse’s perception of pain may serve to extend periods of repetitive self-mutilation. The onset of this stereotypy has been associated with a variety of factors, which include: elevated levels of excitement or stre
