acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

Domestication of the capybara for use as a commercial meat source increases the need to assess the parasites of this animal, especially those which cause disease or may be transmissible to other domestic animals and man. Survey studies have detected a high prevalence of renal filariasis in capybaras, associated with considerable tissue damage. Cruorifilaria tuberocauda Eberhard, Morales, and Orihel, 1976 has been identified as the filaria which produces these infections. Microfilariae distinct from C. tuberocauda have been observed in histologic sections of capybara skin indicating the presence of other filariae in this animal which should be evaluated in terms of their vector requirements, pathogenesis, and potential usefulness as experimental models for human filariasis, especially onchocerciasis. In the present work a morphologic and taxonomic description of Dipetalonema hydrochoerus sp. n. from Colombian capybaras is presented. Larval morphology and development of this species within the ixodid tick, Amblyomma cajennense, are described. The microanatomy of this filaria, as it appeared in tissue sections, is described. Descriptions of Cruorifilaria tuberocauda microfilariae from skin snips and two additional skin-dwelling microfilariae designated microfilaria species 'A' and microfilaria species 'B' are also presented. Evaluation of concentrations of microfilaria species 'A', microfilaria species 'B' and C. tuberocauda microfilariae in weighed skin snips revealed that all three species are unevenly distributed in the skin. High concentrations were consistently observed from the dorsal aspect of the body (top of head, ears, back) while low concentrations of microfilariae were seen in snips from several other body areas. Circadian fluctuations in the concentrations of species 'A' and C. tuberocauda microfilariae were observed. A low undulating wave of microfilarial concentrations, peaking between 0800 and 1000 hours was noted for C. tuberocauda, while a sharp concentration peak was observed at 1000 hours for microfilaria species 'A'. Concentrations of species 'B' microfilariae did not appear to fluctuate in a uniform pattern. The levels of D. hydrochoerus microfilariae in the experimental animals were too low to allow an evaluation of distribution or circadian behavior / acase@tulane.edu

acase@tulane.edu