PLASMA-CHOLESTEROL AND LIPOPROTEIN CONCENTRATIONS IN THE DOG - THE EFFECTS OF AGE, BREED, GENDER AND ENDOCRINE DISEASE

A combined ultracentrifugation and precipitation technique was used to quantify the plasma lipoprotein concentrations of control dogs (n=33) and dogs with diabetes mellitus (n=11), hyperadrenocorticism (n=14), hypothyroidism (n=10) and obesity (n=20). In addition, the effect of b reed type, age and gender on the lipoprotein phenotype was assessed. B reed type and age were found to have no effect upon cholesterol and li poprotein concentrations but the high density lipoprotein cholesterol (HDL-C) concentration was greater in intact females than intact males. Cholesterol concentrations were significantly higher than those of th e control group in dogs with diabetes mellitus (P<0.01), hyperadrenoco rticism (P<0.01) and hypothyroidism (P<0.001). In dogs with diabetes m ellitus this was due to increased concentrations of very low density l ipoprotein cholesterol (VLDL-C) (p<0.01) and HDL-C (P<0.05). The conce ntrations of low density lipoprotein cholesterol (LDL-C) (P<0.05) were significantly increased in dogs with hyperadrenocorticism, while in t he hypothyroid dogs, VLDL-C (P<0.05), LDL-C (P<0.001) and HDL-C (P<0.0 5) were significantly higher than the control group. The cholesterol a nd lipoprotein concentrations in the obese population were not signifi cantly different from control dogs.