Hematology, Ultrastructure and Morphology of Blood Cells in Rufous-Winged Buzzards (Butastur liventer) from Thailand

SIMPLE SUMMARY: Complete blood counts (CBCs) are a manual tool used for the screening of raptor health. These tests require knowledge of blood cell morphology. This study aims to describe the quantitative and qualitative information of blood cells in rufous-winged buzzards (RWB) admitted into the rehabilitation center. The CBCs of 12 out of 17 RWBs were included for descriptive hematologic values. Heterophils were the most prevalent white blood cells in RWBs. One non-parasitized RWB showed hypochromic erythrocytes with PCV 0.18 L/L, which indicated that anemia in RWBs resulted from non-parasitic causes. The blood cells in RWBs are similar to those in other diurnal raptors, except for the lymphocytes. The electron micrographs confirmed the photomicrograph. This report can be used for the baseline information for rehabilitation of the RWBs in Thailand. ABSTRACT: In attempt to treat injured raptors and promote conservation awareness, the Kasetsart University Raptor Rehabilitation Unit (KURRU) was established in 2007. The complete blood counts (CBCs) are a manual tool used for the screening of raptor health. These tests require knowledge of blood cell morphology. This study aimed to describe the preliminary information of the hematology, ultrastructure, and morphology of blood cells in rufous-winged buzzards (RWB). There were 17 RWBs admitted into the KURRU. CBCs were manually performed by veterinary technicians. The morphology and morphometry of blood cells were observed from Wright-stained blood smears. Ultrastructure was observed from uranyl acetate and lead citrate-stained sections. The hematologic values were analyzed and described from individual RWBs that were clinically healthy, negative for blood parasites, and had PCV > 0.30 L/L. Consequently, CBCs of 12 out of 17 RWBs were included for descriptive hematologic values. Heterophils were the most prevalent white blood cells in RWBs. Of these 17 RWBs, 1 non-parasitized RWB showed hypochromic erythrocytes with PCV 0.18 L/L, which indicated that anemia in RWBs resulted from non-parasitic causes. The morphology of blood cells in RWBs was similar to those in other diurnal raptors, except that the lymphocytes showed pale or colorless cytoplasm. The electron micrographs highlighted that the basophil contained two types of granules: homogeneous electron-dense granules and reticulated electron-dense granules. The photomicrographs in this report are the scientific reference for identification of blood cells in RWBs. The CBCs from non-parasitized RWBs (clinically healthy) can be used as a cage mate reference in the KURRU. Additionally, we found evidence that evaluations of blood smears together with CBC examination were important in raptors.