Equine Obesity and Cardiovascular Changes

Obesity has a significant impact on the structural changes in cardiovascular tissue in horses, a recent study has found.

Obesity is known to have significant adverse effects on horse health with laminitis an obvious example, but it can also contribute to other problems such as those affecting soundness or fertility.

In humans, obesity is recognised as a risk factor for cardiovascular problems. However, until now there has been little research into the effect of obesity on the wider cardiovascular tissues of horses. 

A recent study by Natalia Siwinska and colleagues at the Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences in Poland assessed the impact of obesity on the microscopic structure of the heart muscle and selected arteries in horses.

They conducted post-mortem examinations on nineteen draft slaughter horses, comparing specimens from twelve extremely obese (body condition score 9/9, and seven with normal body condition score 4-5/9. They examined specimens of heart muscle and major blood vessels (aorta, pulmonary, coronary and palmar arteries). A report of the work is published in the journal Animals.

Obese animals had increased amounts of pericardial and cardiac fat, and the intima (the inner layer) of the pulmonary artery, coronary arteries and palmar arteries was thicker, compared with the healthy animals. They also found changes in palmar arteries in obese horses, which had a larger lumen diameter and the lumen-to-total diameter ratio compared to the control group.

The structural changes that they found are like those observed in people. The researchers suggest that these changes “may be an indicator of subclinical dysfunction, which could lead to severe disease.”

They suggest that the direct effects of obesity on cardiovascular health and function in horses require further exploration.