Study: Malnourished Horses Require Careful Refeeding

Feeding a malnourished horse is often much more involved than simply offering the horse an unlimited amount of feed until his weight and strength return. There are few nutritional studies that evaluate the refeeding and rehabilitation process, with even less information available explaining how the horse's metabolic function changes during the refeeding period.

Dr. Sawyer Main of the University of Tennessee sought to assess the metabolite profile (called the metabolome) of emaciated horses as they go through the refeeding process.

Ten horses that had been surrendered or sold at auction were used in the three-month study. Each horse was in good health, with normal temperature, pulse, and respiration rates, though they were malnourished.

The first 10 days of the study were considered the critical care period for refeeding. The following 155 days were considered the recovery period. Horses were fed specific diets and blood samples were collected and analyzed throughout the study.

The research team compared the metabolic profiles of the horses when they were malnourished and during the refeeding process. They found that there was a decrease in potentially toxic chemical compounds related to kidney, liver, and muscle function. Energy-related metabolites also changed as the horses were refed.

Refeeding has a profound impact on equine rehabilitation, and care must be taken that the malnourished horses are fed in a manner that does not induce refeeding syndrome. Refeeding syndrome occurs when a starving horse is overfed, resulting in additional metabolic damage, specifically to the kidneys and liver, which are already impaired by malnourishment.

They team concludes that a malnourished horse must be placed on a carefully tailored feeding schedule that slowly reintroduces nutrients so as not to inflict further metabolic damage. The scientists did find differences in metabolomes in younger and older horses; the metabolomes also differed by diet and sex.