Cardiovascular evaluation in overweight and obese dogs

Canine obesity is a multifactorial nutritional disorder characterized by excessive accumulation of adipose tissue with systemic health consequences. However, the cardiovascular effects of obesity in dogs have not been completely characterized. This study aimed to evaluate the clinical, electrocardiographic, and echocardiographic parameters of dogs with normal body condition, overweight, and obesity. Thirty client-owned dogs were divided into three groups of ten: Group 1 (G1, body condition score [BCS] 4-5/9), Group 2 (G2, overweight, BCS 6-7/9), and Group 3 (G3, obese, BCS 8-9/9). All animals underwent physical examination, electrocardiography, and echocardiography, and their canine body mass index and thoracic-to-abdominal circumference ratio were measured. Exercise intolerance and dyspnea were significantly more frequent in G3 (90% and 70%) than in G1 (20% and 10%) and G2 (60% and 10%) (p<0.05). The P-wave (p = 0.030) and QRS (p = 0.049) durations increased progressively from G1 to G3. The left atrial diameter (p = 0.010) and left atrium-to-aortic root ratio (p = 0.011) were significantly greater for G3, and mitral valve abnormalities were more prevalent in obese dogs (p = 0.023). The thoracic-to-abdominal circumference ratio was significantly lower in G2 and G3 (p = 0.003), reflecting abdominal fat redistribution. No significant differences were found in the systolic or conventional diastolic function indices. These findings indicate that obesity in dogs is associated with early cardiovascular alterations, morphometric changes, electrocardiographic conduction delays, and left atrial remodeling in the absence of overt cardiac dysfunction. This underscores the importance of routine cardiovascular monitoring in overweight and obese canine patients.