Scientists are still working to fully characterize the relationship between obesity and degenerative joint diseases such as osteoarthritis. But researchers did determine that horses’ body weight, BCS, and body fat percentage and mass appear to be correlated with blood concentrations of PGE2—a potential joint damage marker. | Photo: iStock

Obesity and its related health issues remain a problem in both horses and humans. Researchers have linked obesity—specifically adipose (fat) tissue—with excessive inflammation biomarker production, but they haven’t yet found a correlation between obesity and degenerative joint diseases, such as osteoarthritis.

So Wendy Pearson, MS, PhD, of the University of Guelph, in Ontario, Canada, and the Nutraceutical Alliance, set out to determine if there’s a link between body fat, horse activity level, and inflammatory biomarkers, specifically prostaglandin E₂ (PGE_2, which is associated with synovial, or joint, inflammation and cartilage matrix depletion) and glycosaminoglycan (GAG, an important joint cartilage component).

The team studied 54 horses residing on private farms in Southern Ontario. They estimated the horses’ body weights and body condition scores (BCS), then categorized horses as thin (a BCS of 3 out of 9, six horses), moderate (BCS of 4 or 5, 18 horses), overweight (BCS of 6 or 7, 19 horses), or obese (BCS=8 or 9, 11 horses). The researchers measured the horses’ body fat mass and body fat percentage and recorded the owner-reported activity level (nonvoluntary, forced exercise). Finally, they collected joint fluid from horses’ knees as well as blood samples to test for PGE₂ and GAG