The aims of the study were to value the safety and the diagnostic relevance of endoscopic liver biopsies in parrots during routinely endoscopic examination and the correlation between histology and a complete liver biochemical profile.

One hundred and seventy five (175) clinically healthy parrots belonging to 10 genera and 26 species, with a body weight that ranged between 127g and 1300g, from the Rescue Centre for Wild and Exotic Animals in Semproniano (Grosseto, Tuscany, Italy) managed by the WWF, were endoscopically examined during a routine check-up. The lateral access to the body cavity was used, and the lateral border of the liver was then grasped and sampled. A blood sample was taken from jugular vein from every subject before performing the biopsy. All animals survived the intervention without any clinical problem. The biopsy specimen was immediately fixed in 10% buffered formalin.

Definitive diagnoses included focal hepatic necrosis, cholangitis-cholangiohepatitis, diffuse chronic-active hepatitis, chronic-granulomatous hepatitis, vacuolar hepatopathy, pigment storage, periportal fibrosis, microvascular dysplasia, abnormal bile-ducts proliferation, mucinous metaplasia of bile duct epithelium and normal hepatic tissue.

These results demonstrate that endoscopic liver biopsy in avian patients is generally well tolerated and can be considered as relatively risk free--highly sensible test to liver status evaluation, as reported in mammals. Additionally, this study reveals an interesting correlation between above mentioned lesions and some biochemical values alterations: increased levels of GGT, GOT, GPT were constantly observed in focal hepatic necrosis; increased values of ALP were observed with phlogosis involving bile-ducts, and plasma LDH elevation was strictly related to acute parenchymatous phlogosis. In the African grey parrots with diffuse chronic-active hepatitis and fibrosis we found a constant increase in GGT levels, and in parrots belonging to the Ara genus we found a constant increase in total bilirubin associated with hepatic phlogosis. Finally, in Aprosmictus erythropterus species with parenchymatous diffuse chronic-active hepatitis, a constant increase in GOT, GPT, LDH, and total bilirubin was constantly observed.

Our results demonstrate that larger, more accurate databases of avian clinical chemistry values are needed to improve the quality of avian internal medicine.