Evaluation of Plasma Cholesterol, Triglyceride, and Lipid Density Profiles in Captive Monk Parakeets (Myiopsitta monachus)

To evaluate potential factors related to avian atherosclerosis, plasma cholesterol and triglyceride values were measured in 35 apparently healthy captive monk parakeets (Myiopsitta monachus). Birds were categorized as healthy or at risk based on body condition score and weight and were also evaluated based on their aviary environmental conditions. Plasma cholesterol mean was 8.008 mmol/L (range: 4.655 to 20.33 mmol/L) or 309.65 mg/dl (range: 180 to 786 mg/dl) for all birds sampled. Plasma triglyceride mean for all birds sampled was 4.364 mmol/L (range: 0.960 to 44.62 mmol/L) or 386.54 mg/dl (range: 85 to 3952 mg/dl). Thirty plasma samples were evaluated through density gradient ultracentrifugation lipid profiling techniques used to examine risk of cardiovascular disease in humans. The resultant lipid density profile graph was determined from the hydrated densities of the following lipids: triglyceride-rich lipoproteins, low-density lipoproteins (LDL) and subfractions, and high-density lipoproteins and subfractions. When analyzed using linear discriminant analysis, lipid profiles of triglyceride-rich lipoproteins, LDL1, LDL2, and high-density lipoprotein 2b subfractions were increased (P < 0.05) in at-risk monk parakeets when compared with healthy cohorts. Gender and diet had no apparent effect on plasma cholesterol or triglyceride concentrations. Cholesterol and triglyceride concentrations and lipoprotein density profiles from captive monk parakeets, a species known to be affected by atherosclerosis, may prove useful as markers for use in future investigation of atherosclerosis in birds. However, the consequence of increased plasma lipid concentrations and changes of lipoprotein profiles on avian health requires additional investigation.