Hematologic Parameters in Raptor Species in a Rehabilitation Setting Before Release

Abstract

To be considered for release, raptors undergoing rehabilitation must have recovered from their initial injury in addition to being clinically healthy. For that purpose, a good understanding of reference hematologic values is important in determining release criteria for raptors in a rehabilitation setting. In this study, retrospective data were tabulated from clinically normal birds within 10 days of release from a rehabilitation facility. Hematologic values were compiled from 71 red-tailed hawks (Buteo jamaicensis), 54 Eastern screech owls (Megascops asio), 31 Cooper's hawks (Accipiter cooperii), 30 great-horned owls (Bubo virginianus), 28 barred owls (Strix varia), 16 bald eagles (Haliaeetus leucocephalus), and 12 broad-winged hawks (Buteo platypterus). Parameters collected included a white blood cell count and differential, hematocrit, and total protein concentration. Comparisons were made among species and among previously published reports of reference hematologic values in free-ranging birds or permanently captive birds. This is the first published report of reference values for Eastern screech owls, barred owls, and broad-winged hawks; and the first prerelease reference values for all species undergoing rehabilitation. These data can be used as a reference when developing release criteria for rehabilitated raptors.

Laboratory blood analysis in Strigiformes—Part I: hematologic reference intervals and agreement between manual blood cell counting techniques

“…Therefore, parametric techniques are not recommended when reporting WBC RI in Strigiformes, contrary to what has been previously reported in the literature. The upper limit of the RI for WBC count was also high for most Strigiformes species, in agreement with previous reports . However, the 90% CIs around these limits were wide in our study, suggesting a lack of precision and a wide variability.…”

“…Prior studies did not use recommended statistical techniques to determine RI of owl hematologic variables, or had a low sample size (< 20); and in some reports, the manual technique used to determine the WBC count was not disclosed . In this study, RI for WBC differential counts were based on PBT, as it is considered the gold standard .…”

Prognostic indicators associated with early mortality of wild raptors admitted to a wildlife rehabilitation centre in Spain

“…These results suggest that severe lesions involving neurological structures usually carry a fatal prognosis, despite good BC. A large number of studies have been published referencing haematological and biochemical values, and their application in the veterinary treatment of individual wild raptors (Spagnolo et al 2008;Gelli et al 2009;Hern andez & Margalida 2010;Black et al 2011). …”

Quantitative and qualitative characteristics of blood cells in black‐shouldered, Brahminy, and black kites

“…Examination of blood films is an important component of hematologic investigations and provides useful information about blood cell alterations . There are some reports on the morphology and ultrastructure of avian blood cells in Thailand and hemograms from other raptors; however, variations in cell characteristics exist among species within the Aves class . Normal hematologic values vary between the species as well .…”