Do capybaras enhance their resistance to parasites under nutritional stress?

EBERHARDT, MARÍA AYELÉN TERESITA; MANZOLI, DARÍO EZEQUIEL; FERNANDEZ, CAMILO; TORRENT, JORGELINA; IGLESIAS, CARINA; BELDOMENICO, P.M.

Encuentro; 100th Annual Meeting of the American Society of Mammalogists; 2021

American Society of Mammalogists

The interactions between parasites and their hosts appear to be context-dependent, and stress modulates the immune system and affect these interactions. Against infection, hosts engage in two distinct defence strategies, tolerance and resistance. Resisting involves decreasing parasitefitness (survival and/or output). Resistance mechanisms could be energetically costly and thus it is expected that such expenditure is could be afforded fully by hosts in good condition. To evaluate the effect of nutritional stress on parasite burdens and output to specific nematode (count ofadult and mean number of eggs/female) and coccidians (number of oocysts/gram of faeces) in capybara we conducted an experiment under controlled conditions using 24 wild-caught young females. Animals dewormed and randomly allocated into two groups: control (fed ad libitum)and food-restricted (40% of the food quantity consumed by control group) during 15 weeks. After 10 weeks, capybaras were inoculated with two kinds of parasites: Eimeria spp. and Strongyloides chapini. There were no significant difference between treatment groups in oocytes sheddingafter the inoculation (first peak). However, in the following weeks, food-restricted capybaras tended to shed less oocyts than controls. While counts of S. chapini did not differ among treatment groups, females in capybaras of food-restriction groups laid less eggs than females in control groups