Exercise and the Underweight Horse

Owners of underweight riding horses walk a tightrope: too much exercise keeps horses from gaining weight, whereas too little exercise delays performance goals, sometimes indefinitely. How to plan a nutritional and athletic future for these horses depends principally on the nature and history of undernourishment.

If a horse arrives at a new facility underweight, as a recently retired racehorse or a weaned broodmare might, the reason for the boniness might be reasonably easy to establish. In the case of the racehorse, frequent training and racing kept him toned and free of excess condition; as far as the broodmare, too few calories were likely tendered during lactation, which pulled the mare into a state of emaciation.

Because the causes of their thinness have been removed (i.e., hard work and a hungry foal), there’s a good chance these horses, in time, will gain weight with an increasing plane of nutrition.

“Assuming they are sound of body and mind, these two can be ridden lightly during the weight-gain process. Exercise may delay weight gain ever-so-slightly as some calories are diverted from tissue-building to athletic endeavors,” said Catherine Whitehouse, M.S., a nutrition advisor with Kentucky Equine Research (KER). “Because moderation is key, these periods of weight gain offer an opportunity for low-level conditioning, which provides a worthy foundation for harder work down the road.”

If a horse you have known well for a while drops weight on an unchanging diet, a veterinary examination is in order, with an eye on dental health, parasite burdens, and gastric well-being. If a horse is cleared by a veterinarian, a complete ration evaluation should be completed by a qualified equine nutritionist, who will collect information about every component of the horse’s diet: hay, pasture, concentrates, supplements, and any other feedstuffs. Like the previous examples, an elevation in nutrition will likely solve this horse’s problems if given adequate time.

If, on the contrary, a medical condition is discovered by a veterinarian on checkup, special nutritional considerations might apply. “Horses with certain metabolic diseases require specialized nutrition plans, as do senior horses with unexplained weight loss. Until a cause for the weight loss can be identified, it might be best to limit this horse’s exercise, though consultation with the veterinarian will help determine performance expectations,” explained Whitehouse.

Skinny horses have their own set of challenges when it comes to tack fit, and this might be a consideration in determining when to start work. Thin horses with Himalayan withers, for instance, will require meticulous saddle-fitting, oftentimes with extra protection from pads. Without careful attention to this, rubs may occur, which can delay riding further. Thin-skinned horses seem to be particularly sensitive to injuries from ill-fitting tack.

Learn more about feeding underweight horses.