Clinically healthy overweight and obese dogs differ from lean controls in select CBC and serum biochemistry values.

Background: Obesity is a global disease, affecting nearly half a billion people. Unfortunately, this trend is mirrored in our canine population.

Objectives: As obesity is a complex inflammatory disease, there is a need to determine whether routine medical screening tests may indicate, or be influenced by, its presence. The objective of the current study was to determine if significant differences exist between CBC and biochemical profile values from control vs overweight/obese, client-owned dogs considered clinically healthy.

Methods: Dogs presented for routine health examinations, including minor dental or elective surgical procedures, were retrospectively identified from a hospital population. Animals were allocated to 2 categories based on body condition score (BCS), and data were analyzed by Mann-Whitney nonparametric analysis with statistical significance at a P ≤ .05.

Results: After exclusions, 116 dogs were assigned to the overweight/obese group (BCS ≥ 7) and 240 dogs to the control group (BCS = 4-6). Overweight/obese dogs had higher total leukocyte counts and higher plasma protein and globulin concentrations. Other differences were attributed to decreased serum water fraction (increased sodium, albumin, calcium, and anion gap) in the overweight/obese group. Interestingly, chloride concentration was decreased (in the face of increased sodium) in the obese group.

Conclusions: There is CBC and biochemical evidence to support the concern that obesity influences laboratory values, even in dogs considered clinically healthy. Prospective studies aimed at characterizing these changes are needed to provide insight into the connection between obesity and its comorbidities.