Assessment of abdominal fat distribution by computed tomography in obese dogs

Obesity is a risk factor for canine health but there has been no study on the tendency of body fat accumulation naturally occurring in obese dogs. This retrospective observational study aims to evaluate the tendency to accumulate visceral and subcutaneous fat using computed tomography (CT) in naturally occurring obese dogs. The study included 15 dogs with a body condition score of 8 or 9 that underwent abdominal CT scans. Total fat area (TA), visceral fat area (VA), subcutaneous fat area (SA) and body area (BA) were measured by non-contrast transverse image at the third lumbar vertebra (L3) and the sixth lumbar vertebra (L6). TA, VA and SA were divided by the length of the L6 body to account for different body size. The ratio (rTA, rVA, and rSA) was then calculated. rTA and rVA were significantly higher at L3 and rSA was significantly higher at L6. TA/BA and VA/SA were analyzed at L3 and L6, respectively. No difference in TA/BA between L3 and L6 was shown while the VA/SA was significantly higher at L3 than at L6 (P = 0.001). There was no difference of visceral and subcutaneous fat distribution between the male and female groups. The findings of the present study suggested that visceral and subcutaneous fat are accumulated at L3 and L6, respectively, and obese dogs tend to accumulate more visceral than subcutaneous fat.