Overweight horses require a little extra attention, but obesity is fixable and can be treated like any other health problem. | iStock

Learn how nutritionists took 3 horses from fat to fabulous

Suggest a horse is at risk for colic, and people jump into action. Tell someone their horse is overweight, and the reaction can be different. Some owners might be in denial about their horses’ extra body condition, others even consider it an insult. However, equine obesity is a growing problem. Extra weight makes it harder for performance horses to jump, run, or turn. Obesity can also increase any horse’s risk for developing health problems such as laminitis, equine metabolic syndrome, and heat or exercise intolerance.

“Overweight horses require a little extra attention, but obesity is fixable and can be treated like any other health problem,” says Lori Warren, PhD, PAS, an associate professor of equine nutrition at the University of Florida, in Gainesville. “If somebody is telling you your horse is overweight and that losing a little can alleviate a problem, you should take that seriously and not personally.”

Weight’s Impact on the Equine Body

Many researchers have examined the link between obesity and arthritis in horses and other species. The jury is still out if obesity alone can cause arthritis, says Jennie Ivey, PhD, PAS, an associate professor and extension equine specialist at the University of Tennessee, in Knoxville. However, added weight does increase systemic inflammation. 

“The impact on the joint itself is still under review, but studies have shown horses are in a higher inflammatory state when they are overweight,” she says.   

Warren added that overweight performance horses already exert extra stress on their joints, potentially exacerbating arthritis. Inflammation is part of exercise, and it has its purpose in breaking down tissues and rebuilding them stronger, but in excess the breakdown exceeds the rate of repair. 

“Cumulative inflammation may start the onset of arthritis earlier in life,” Ivey says. “That might mean the horse needs more layup time or gets injured after a misstep because they tire sooner.” 

In 2021 researchers from North Carolina State University found that despite the health risks of obesity, overconditioned horses tend to get rewarded in the show pen. In a survey the study investigators asked hunter judges how they would rate horses based on condition. Most agreed they would penalize an underweight horse more than an overweight one.