Savage behavior often follows one or more days of apparently normal acceptance, bonding, and protection of the foal, and no one really knows what sets it off. It can be distinguished from accidental injury, though, by the pattern of attack. "If the foal has a bite mark on the crest of his neck, you can almost guarantee it won't be a one-time incident," McDonnell said. Such aggressive behavior, she added, can sometimes be associated with feeding aggression.
Mares, as a rule, are excellent mothers to their offspring, but abnormal or inadequate maternal behavior does occur in rare instances, writes Karen Briggs in the December edition of The Horse. The causes are poorly understood, although we do know they're more common among first-time mothers, that there might be a genetic predisposition among certain bloodlines, and that mares that prove to be poor mothers the first time around often repeat the behavior with subsequent foals. Abnormal maternal behavior usually surfaces immediately after birth, but in a few cases it might first become evident after one or several days of apparently normal acceptance and nurturing of the foal. Behaviors to watch out for include the following: (A) Ambivalence -- This is an absence of bonding and protective behavior and attention to the foal. The mare just doesn't seem interested in the new arrival. "She doesn't engage in that early 'cross-talk' with the foal," said Dr. Sue McDonnell, head of the Equine Behavior Program at the University of Pennsylvania's School of Veterinary Medicine. It often occurs when the mare (and/or the foal) is sick, weak, or medicated. Normal behavior might return as the strength of the compromised individual returns. Sometimes, too, bonding behavior between the mare and foal is interrupted when they are separated or there is interference immediately after birth (as occasionally happens when owners try to "imprint" foals). (B) Extreme protectiveness -- Some mares become aggressively protective of their foals to the point of being dangerous to handle and potentially dangerous to their babies. While rushing to get herself between her foal and any perceived threat (from an owner, veterinarian, or even the barn cat), such a mare might crush her foal between a man-made object such as a stall wall, or trample him. This behavior often is misinterpreted as a deliberate attack on the foal. The intensity of overprotective behavior usually wanes after a few days, but in some cases, it persists until the foal is weaned. (C) Fear of the foal -- Some mares, particularly first-time mothers, seem genuinely afraid of their foals. They don't appear to recognize them as horses, much less "theirs." Instead of approaching and bonding, they are intent on getting away from the new "foreign object" in the stall. Many of these mares can be acclimated to the foal's presence, as they would any other strange object, but they never really bond with them. (D) Avoidance of nursing -- This probably is the most common form of aberrant maternal behavior. It really isn't a rejection of the foal, but just a reluctance to have him nurse. The cause is pretty easy to discern -- some mares are very touchy about their udders, especially when there's edema present and milk glands are swollen and full for the first time. "Nursing avoidance is largely preventable," McDonnell said. "It's worth getting the mare used to having her udder touched and handled before she foals. If she gets really swollen, you may even want to milk her to relieve the pressure. Save the colostrum (the antibody-rich first milk present in the udder only in the hours right after birth), then let the foal suck, and give him the colostrum by bottle afterward." (E) True foal rejection -- This is the rarest manifestation of abnormal maternal behavior, but it's also by far the most serious. When a mare turns her aggression toward her foal, the situation truly becomes life-threatening for him. She might savagely attack him, biting or grabbing him by the neck or withers and lifting or tossing him against a fence or wall. She also might pin him to the ground and stomp on him repeatedly.