Hematological parameters and the variations resulting from stress of Alouatta caraya during a wildlife rescue program in Brazil.

Abstract

Deforestation and habitat fragmentation are major threats to the conservation status of New World primates, such as the howler monkey (Alouatta caraya) in Brazil, where vegetation destruction is often associated with projects such as Small Hydro Power Plant (SHP) construction. The resulting stress from the implementation of this type of enterprise may be a factor that influences individual susceptibility against pathogens and can determine the success or failure of mitigation measures proposed by responsible and/or requested companies by environmental agencies. To perform health monitoring and to understand physiological changes that ensued from the stress of capturing and keeping primates in captivity, we determined the blood profile of A. caraya rescued at the time of capture (N = 15) and in captivity (N = 11). Complete blood counts (CBCs) performed at the time of capture showed hematological changes compatible with acute stress, such as evident neutrophilic leukocytosis (WBCs; females = 20.48 ± 7.26; males = 18.78 ± 10.39 × 10(9) /L). In captivity, monocytosis was observed in both sexes (females = 1.34 ± 0.26; males = 0.39 ± 0.32 × 10(9) /L; U-test, P = 0.01), suggesting chronic stress. In females, there was also statistically significant eosinopenia (0.28 ± 0.10 × 10(9) /L; U-test, P = 0.01) and hematocrit increases (39.00 ± 1.41%; U-test, P = 0.01). Thus, data shows the impact of both capture related acute stress as well as captivity chronic stress, suggesting that primate management in the implementation of these projects causes significant changes in physiological parameters and, consequently, animal health. Whereas chronic stress is an inducer of immunosuppression and susceptibility to pathogen factors, monitoring hematological parameters in captive animals can act as an indicator of health status, contributing to the success of management and conservation wildlife programs. Am. J. Primatol. 77:246-253, 2015. © 2014 Wiley Periodicals, Inc.