Association of plasma lipid levels with atherosclerosis prevalence in psittaciformes

The prevalence of atherosclerosis is high in the captive psittacine population and increases with age and female sex. The genera Psittacus, Amazona, and Nymphicus are predisposed to atherosclerosis, whereas the genera Cacatua and Ara are less susceptible. Plasma cholesterol and lipoprotein abnormalities have been suggested as risk factors in the development of atherosclerosis as observed in mammals. To investigate whether the psittacine genera susceptibility to atherosclerosis and the known risk factors of age and sex could be associated with differences in the lipid profile, a retrospective analysis was conducted on blood lipid values from 5625 birds. Prevalence values were obtained from a previously published, large, case-control study and were compared with identified trends in plasma lipid profiles. Genus-specific differences were identified in plasma total cholesterol values that corresponded to observed trends in the prevalence of clinically important atherosclerotic lesions, which were also highly correlated. The effect of age was significant but was mild and may not account for the dramatic increase in atherosclerosis prevalence observed with age. In addition, Quaker parrots ( Myiopsitta monachus ), which were used as experimental models for psittacine atherosclerosis and dyslipidemia, were found to have the highest values in all lipid profile parameters. The results of this study suggest that the differences observed in prevalence among species of the psittacine genera may partly be explained by differences in plasma total cholesterol levels. Results also support the use of Quaker parrots as models for studying atherosclerosis and dyslipidemia.