Leukocyte changes in diseased non-domestic birds

Abnormal complete blood counts on four birds of prey, three waterfowl, and one pigeon are reported. Heterophil counts exceeding 100 X 10(9)/L were seen in each group of birds, and were associated with chronic infections. Heteropenia with left shift and toxicity was an indicator of poor prognosis, and occurred with terminal disseminated mycotic infection in birds of prey, and disseminated bacterial infection in the other avian patients. Morphologic criteria indicating immaturity and toxicity appeared more important for determining outcome than the magnitude of the heterophilia, and high heterophil counts did not preclude overwhelming fatal infection. Monocytosis occurred in only one bird of prey with a mycotic infection. Criteria similar to those applied to mammalian leukograms appear to correlate with prognosis in avian patients.