Hematological profile of free-living opossums (Didelphis aurita andDidelphis albiventris) in the state of São Paulo, Brazil

Abstract

Although opossums are frequently rescued in urban and peri-urban environments, interpreting laboratory test results is difficult due to a lack of studies providing reference values for hematological parameters in these species. This study aimed to establish the hematological profile of free-living opossums in the state of São Paulo, Brazil. Blood samples were taken from 52 individuals of two species: 32 white-eared opossums (Didelphis albiventris) and 20 black-eared opossums (Didelphis aurita) to assess complete blood counts. These animals had been rescued by two institutions, one in Sorocaba and the other in São Paulo city. Blood samples were taken to assess hematological parameters. The mean values and standard deviations obtained from the D. albiventris samples were: red blood cells (x106/µL) 3.68 ± 0.50, hemoglobin (g/dL) 8.85 ± 2.07, PCV (%) 29.65 ± 5.66, MCV (fL) 83.81 ± 7.65, MCH (pg) 25.33 ± 2.79, MCHC (% ) 29.40 ± 1.77, white blood cells (/µL) 12.523 ± 4.282, segmented neutrophils (/µL) 5.962 ± 2.954, lymphocytes (/µL) 5.944 ± 1.753, eosinophils (/µL) 427 ± 378, monocytes (/µL) 273 ± 193. For D. aurita, the average values were: red blood cells (x106/µL) 4.27 ± 1.11, hemoglobin (g/dL) 11.32 ± 2.83, PCV (%) 37.88 ± 7.07, MCV (fL) 92.38 ± 19.29, MCH (pg) 26.47 ± 5.53, MCHC (%) 29.16 ± 3.94, erythroblasts (/100 leu) 0.24 ± 0.55, white blood cells (x103/µL) 9.883 ± 5.333, segmented neutrophils (/µL) 5.677 ± 3.378, lymphocytes (/µL) 2.421 ± 1.337, eosinophils (/µL) 972 ± 806, monocytes (/µL) 229 ± 186 and basophil (/µL) 35.56 ± 53.95. Different geographical regions, climates, and feeding, as well as the presence of parasites, are variables that can influence the parameters of the erythrogram and leukogram. The hematological values reported in this study may help veterinarians treat opossums by contributing to existing information on these marsupial species.