Standardization of coagulometric tests in griffon vultures (Gyps fulvus): PT, aPTT and factor V reference values

The avian coagulation system has structural and functional features hinder the direct application of commercial diagnostic products developed for humans. Griffon vultures (Gyps fulvus) are frequently admitted to wildlife rehabilitation centers with coagulation disorders due to lead or rodenticide poisoning. These disorders are challenging to diagnose due to the absence of reference intervals and validated coagulometric measurement protocols. The aim of this study was to standardize the measurement of prothrombin time (PT), activated partial thromboplastin time (aPTT), and coagulation factor V (FV) in griffon vultures using diagnostic reagents from human medicine, while also analyzing for differences according to sex, cause of admission, and weight. Plasma samples from 17 healthy individuals were analyzed using a semi-automated coagulometer and standard calibration reagents for human use. A specific protocol was established for the analysis of griffon vulture plasma using human diagnostic reagents adapted for the analysis. PT, INR, and FV could be successfully assessed under these conditions, allowing the establishment of reference intervals, whereas aPTT values were markedly prolonged and highly variable. These results allow for the establishment of a standardized protocol for accurately assessing coagulation in griffon vultures, which may serve as a reference for other avian species. The protocol could improve the clinical follow-up of cases of lead or rodenticide poisoning and ultimately contribute to wildlife conservation.