Help, My Horse is Too Fat!

Q: My 14-year-old mare has severe obesity problems. The veterinarian ruled out Cushing's disease because she does not exhibit the typical Cushing's traits. I am afraid to work her for fear that any overexertion will harm her physically. Are there any dietary supplements that can help to speed up her metabolism rate?

Cindy Baker, Verona, Ky.

A: Obesity can be a very challenging problem to address. Some horses are "easy-keepers" in that they require minimal calories to sustain their body condition. Others can have underlying medical conditions contributing to the obesity. Some can suffer from a combination of both. Therefore, a thorough history and physical exam should be performed in order to rule out any medical conditions that might be causing the obesity. If necessary, blood tests can be performed to check for conditions such as Cushing's disease or hypothyroidism. Thyroid supplementation can help speed up metabolism if a deficiency in thyroid hormone is found on the blood test. The mare's de-worming status should be studied as this might also be contributing to her potbellied appearance.

Once any medical condition has been ruled out, then an evaluation of the mare's nutrition should be addressed. Looking at the type and amount of hay fed is necessary in determining whether an adjustment can be made. Adjustments should focus on decreasing or eliminating alfalfa hay and increasing fiber without adding any extra calories. Both weight loss and an increase in exercise should be gradual and carefully monitored by your veterinarian. Your veterinarian can provide you with additional helpful resources concerning the overweight horse that can be found on the American Association of Equine Practitioners' web site (

About the Author

Cynthia V. Gutierrez, DVM

Cynthia V. Gutierrez, DVM, is a veterinarian based in San Juan Capistrano, Calif.

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