Many horse owners are familiar with the Henneke body condition scoring (BCS) system and might have even used it a time or two. But with equine obesity, insulin resistance, and other metabolic disorders on the rise, a group of British researchers felt the need to develop and test a different type of scoring system—one that would specifically measure regional adipose (fatty) tissue in horses.

The group designed the new EQUIFAT scoring system to measure a variety of adipose tissue stores, including:

  • Omental (near the stomach);
  • Mesenteric (near the small intestine);
  • Epicardial (around the heart);
  • Nuchal crest (top of neck); and
  • Rump.

“This tool is essential only because information about internal (fat) reserves—specifically omental and mesenteric adipose tissues—cannot be obtained in living horses,” said Caroline Argo, BSc, BVSc, PhD, Dipl. ECAR, MRCVS, head of veterinary education and the Department for Veterinary Clinical Sciences at the University of Surrey, in the U.K. “Because these depots are only visible at surgery or post-mortem, it is the only mechanism we have to collect information about the size of these depots and its relationship with health and disease.”

In the first part of their recent study, Argo and fellow researchers set out to test EQUIFAT using images from 38 randomly selected mixed breed horses presented for slaughter at a U.K. abattoir. Twenty-four participants, including 17 veterinary surgeons, five clinical pathologists, and two scientific researchers, used a scoring system ranging from 1 to 5 (where 1 equates to no fat visible and 5 means excessive fat present) to assess the images. Some participants were allowed to use half scores while others could only use whole numbers.

“It appeared that the EQUIFAT scoring system was applied with more ease when the use of half scores was permitted,” the study authors noted. “Therefore, it would be recommended that half scores are allowed for future use.”

In the second part of the study, the researchers applied the EQUIFAT system to a larger population of horses, also in the abattoir setting, to see how the scores correlated to BCS. A single experienced observer body condition scored the horses, focusing on six anatomical locations, including the neck, withers, loin, tailhead, ribs, and shoulder using the Henneke BCS system ranging from 1 (very poor) to 9 (extremely fat).

The researchers found that fat in the abdominal region had a strong positive association with BCS, suggesting that the intra-abdominal depot might serve as a long-term fat storage area. However, researchers were surprised to find no association between mesenteric or epicardial fat scores and BCS.

In the future, the team said, use of the EQUIFAT system could allow additional data collected at laparotomy (a surgical incision into the abdominal cavity) or post-mortem to be collated with clinical findings.

The study, “EQUIFAT: A novel scoring system for the semi-quantitative evaluation of regional adipose tissues in Equidae,” was published in PLoS One