Plasma lipoprotein concentrations in the dog: the effects of gender, age, breed and diet.

Earlier studies of canine lipoprotein metabolism have frequently not taken into account such variables as age, gender, lifestyle or feeding status. In the last years, many changes to lifestyle and feeding of dogs have occurred. In this study, C-tot, C-HDL, C-LDL, triglycerides and lipoprotein fractions were determined in 251 healthy dogs by means of enzymatic methods and through the electrophoretic technique. All data were analysed by multifactor anova test to determine which factors (age, gender, breed and diet) have a statistically significant effect (p < 0.05) on the determined parameter and subsequently Bonferroni's test was applied where necessary. Gender, age, breed and diet can significantly affect lipid metabolism, in particular lipoproteins involved in cholesterol plasma transport; on the contrary, triglycerides are not influenced by the same factors. The most important observation about age is the high level of C-LDL in puppies under 1 year of age. The highest cholesterol concentrations are found in Rottweiler but high values of plasma cholesterol are found also in Pyrenees Mountain dog and a great level of C-LDL in Labrador. Diet has shown a great influence on lipidic metabolism: dogs fed with different high-quality dry foods had significant differences in plasma cholesterol values (C-tot, C-HDL, C-LDL,), in particular, dogs fed with a diet rich in fish and fish-by-products have shown the lowest levels of C-tot, C-HDL and C-LDL.