INVESTIGADORES
BELDOMENICO Pablo Martin
congresos y reuniones científicas
Título:
Stress and parasitism intensity in capybara (Hydrochoerus hydrochaeris): an experimental study
Autor/es:
EBERHARDT, MAT; COSTA, SA; GAGGIAMO, C; TARRAGONA, E; MAGNI,C; WELSCHEN, N; ROCHI, M; PICASSO, JP; MORENO, P; RACCA, A; ROBLES, R; BELDOMENICO, PM
Lugar:
Puerto Iguazú
Reunión:
Conferencia; LVII Annual International Conference of the Wildlife Disease Association; 2010
Institución organizadora:
Wildlife Disease Association
Resumen:
It is now broadly accepted that parasites influence wildlife population dynamics. In turn, hosts may
influence parasite dynamics, as parasitism intensity is dependent on the intrinsic susceptibility of the
host. Our goal was to evaluate experimentally if induced stress increases the gastrointestinal
parasitism intensity in capybaras. Twenty-six young captive-bred females were randomly allocated
into 6 enclosures and received either of three treatments: two groups were fed a restricted diet (40%
less), other two groups were frequently physically restrained, and the remainder two groups served as
controls. After three months, all animals were euthanized and multiple samples and measurements
were collected. Growth and body condition were substantially affected by both treatments, especially
in the food-restricted group. However, blood cell counts and lymphoid tissue weight did not differ
across groups. Coccidian intensity was significantly higher in treated animals than in controls,
especially in the food-restricted groups. Nematodes, however, did not show such difference.
Moreover, the subfamily Viannainae was found at higher loads in controls than in physically
restrained ones, and the difference was similar and almost significant with foot-restricted capybaras.
Within each treatment, however, a negative association was found between measures of body
condition and coccidians, Strongyloides chapini and Viannainae. Our results revealed that while
parasite loads were negatively associated with host condition, their relationship with nutritional and
psychophysical stress in capybaras differed depending on the parasite species. Further studies should
explore if such differences are a consequence of differential allocation of resources in the
physiological economy (e.g. trade-offs between somatic effort and immunity), or, rather, differential
parasite uptake.