Question

I own an eight-year-old, 1400-lb Thoroughbred mare that is back in light training following a long convalescence. She is kept almost exclusively in the pasture except when being fed meals, which consist of a scoop each of complete feed and soaked beet pulp, and a multipurpose vitamin and mineral supplement. She is offered plenty of grass/ alfalfa hay. My mare becomes muscle sore and irritable at times, and during these episodes she will begin weaving in her stall, sometimes to the point of neglecting her feed. Any thoughts?

Answer

Assuming you have ruled out a behavioral cause for your mare’s anxiousness in the stall (for example, separation from her herd mates), her irritability, discomfort, and occasional lack of appetite might have their origins in the gastrointestinal tract. Her return to work, possibly more stressful for her than you realize, could exacerbate her anxiety, which might manifest as discomfort.

Gastric ulceration and hindgut acidosis are the two possibilities that come to mind. Though these syndromes are usually the result of feeding management issues, some horsemen believe that anxiety might play a role in their development. A veterinarian can perform an endoscopy to definitively determine if your mare has gastric ulcers. If ulceration is found, the veterinarian will prescribe an appropriate treatment to heal the ulcers, and then you can follow up with an over-the-counter ulcer preventative.

There is, however, no surefire method to ascertain if the mare is suffering from hindgut acidosis, but her symptoms suggest it. A time-released hindgut buffer especially manufactured for horses will likely ease the symptoms of acidosis.

Because your mare is a Thoroughbred that is returning to work after an extended layoff, would not entirely overlook the possibility of some mild form of tying-up. In addition to a well-planned exercise regime of slowly increasing demands, switching her to a low starch, high-fat diet has been known to eliminate the ill effects of tying-up in many horses. Adding a quick-acting natural-source vitamin E supplement such as Nano-E may also provide the additional antioxidant protection she needs to reduce muscle damage during and after exercise. If the muscle soreness continues or worsens, certainly a veterinarian should be consulted.

 Solving problems such as these sometimes requires the cooperation of both veterinarian and nutritionist, working together toward the common goal of finding comfort for your mare.