Establishing hematologic and biochemical reference intervals for the endangered Lear's macaw (Anodorhynchus leari)

The Lear's macaw, Anodorhynchus leari (Psittaciformes, Psittacidae), is an endemic species of the Caatinga region in Brazil. With only a few free-living individuals that are constantly under threat from agricultural clearance, hunting, and trapping, A. leari is classified as "endangered" by the Red Book of Endangered Brazilian Fauna and by the International Union for Conservation of Nature. At the same time, the number of individuals in captivity has been growing due to the efforts of biologists and veterinarians in zoological parks to reproduce this species. Thus, having species-specific reference intervals for hematologic and biochemical measurands is essential to assess the health status of these captive and wild birds and guarantee their reproductive success.

This study aimed to determine reference intervals for hematologic and biochemical measurands for A. leari kept in captivity in São Paulo Zoo, Brazil.

Blood samples from 32 individuals were selected based on inclusion and exclusion criteria. Only samples from adults and healthy individuals were included in this study. All statistical analyses were performed according to the American Society for Veterinary Clinical Pathology guidelines and available literature.

Reference values and reference intervals were determined for the captive population of Anodorhynchus leari.

This is the first study to establish reference intervals for A. leari, which can aid the veterinarian in the interpretation of laboratory test results, helping in the diagnosis, treatment, and monitoring of diseases of this endangered species of Brazilian fauna.