Clinical aspects, morphometry, and morphology of blood cells of the emu (Dromaius novaehollandiae) reared in captivity

Abstract

The emu, or Australian ostrich (Dromaius novaehollandiae), is a native to the Australian plains. Understanding the hematology and clinical aspects of emus is necessary so as to outline sanitary measures and guarantee production and breeding management in captivity. This study evaluates the clinical aspects, the morphometry, and the morphology of emu blood cells reared in captivity, in the city of Campos dos Goytacazes, state of Rio de Janeiro, Brazil. Fifteen animals of either sex reared in the scientific nursery of Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF) were clinically examined before egg hatching. This group included three males, which also started the egg incubation period, that were analyzed during two periods (during incubation and off incubation). Blood samples were collected, and smears were prepared and stained for morphometric and morphological analyses. The results show that the peculiar behavior of emus during incubation triggers important changes in clinical status, like weight loss, reduction in rectal temperature, and in heart and respiratory rates of animals. Blood cell morphometry revealed that heterophil had the lowest morphometric index and were the most closely spherical cells in the emus examined. Erythrocytes presented the highest morphometric index, which lends this cell type its ovoid shape.