If your horse is overweight, you are not alone. Equine obesity has risen dramatically in recent years. Researchers have been studying the issue in hopes of learning more about the trend, but as it turns out, many have left out one important factor: seasonal variation.

British researchers recently set out to examine the prevalence and risk factors associated with equine obesity at different times of year, taking seasonal variation into account.

“I don't think obesity is acceptable at any time of year, as it carries a large number of associated health risks,” said Sarah Giles, a PhD candidate at the University of Bristol, in England, and lead researcher of the study. "However, some breeds do naturally store fat during summer months for use during winter conditions."

Giles and her fellow researchers used the 9-point Henneke body condition scoring system and belly girth measurements (both measured by a single trained observer) and owner questionnaires (including age, breed, sex, additional feed, exercise regimen, etc.) to assess obesity in 96 leisure horses with six or more hours of daily pasture turnout. To compare seasonal variation, the team collected data at the end of winter and during the summer