To establish reference intervals in orange-winged Amazon parrots ( Amazona amazonica ) for the complete blood count, plasma biochemical values, and lipid panel and to evaluate age- and sex-related variations, blood samples were obtained from 29 healthy juvenile and adult parrots. Concentrations of total protein, bile acids, phosphorus, total cholesterol, low-density-lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol were significantly higher in adult compared with juvenile birds, while uric acid concentration was significantly higher in juveniles. The white blood cell count, lymphocyte count, and phosphorus and potassium concentrations were significantly higher in females, while chloride concentration was significantly higher in males. In this species, direct measurement of LDL-C resulted in lower concentrations than LDL-C calculated with the Friedewald formula. Assessment of the agreement between the calculated and measured LDL-C concentrations indicated a systematic bias of 19.1 mg/dL and a proportional bias of 1.07. A correction factor of -19 mg/L could be applied to the Friedewald formula, to obtain a result closer to the measured LDL-C, providing clinically acceptable (<20% difference) agreement in 66% of the samples. Triglyceride concentrations within the range measured in healthy birds of the present study did not significantly affect the bias between calculated and directly measured LDL-C. Further studies are needed to investigate the impact of nutritional factors, genetics, and exercise on biochemistry and lipoprotein panel analytes in orange-winged Amazon parrots.
Keywords: Amazona amazonica; avian; hematology; lipid panel; orange-winged Amazon parrots; plasma biochemistry; reference interval.