Fat or Obesity in Horses
  by Robert N. Oglesby DVM

Overly fat or obese horses have become the number one nutritional problem in horses kept in affluent societies and continues to grow toward the overall number one health problem of horse owners. We define obesity not by any particular weight of a horse but by body condition score which is a rough measure of how much fat the horses is carrying. Horses are healthiest when they are carrying a Henneke body condition score of between a 5 and a 6. This will vary a bit depending of the type work a horse does ...more on body condition scoring.

Horses tend to eat the amount of feed needed to meet its energy needs but also has some amount of chewing time requirements and fullness feeling requirements that control their desire to feed. There are several reasons horses under modern management regimens may become obese:

• If the feed is very palatable or has high energy density horses easily eat more than required to meet their energy needs.
• The amount of exercise low so caloric needs are low.
• The horses metabolism is unusually energy conserving. Though this is related to exercise it is also a factor unto itself with a almost 300% range in energy requirements in similar horses.

Even mature (stemmy) cultivated pasture and hays represent much better than average that occurs naturally and simply restricting access to pasture may not be enough. With restricted access to forages horses speed up their rate of consumption and can consume a whole days forage in as little as 6 hours as opposed to the more leisurely 16 hours when offered free choice.

If a horse chronically takes in more energy than he expends, weight gain occurs and if it continues the horse becomes obese with a body condition score greater than a 7. There are serious medical and psychological effects from chronic excessive feeding. This article discusses the causes and health consequences of obesity and how to go about correcting it while keeping your horse happy.