Epidemiologycal studies on strongylids in sheep. l. Description of the annual pattern of eggs output in hoggests

Christian Crempien L.1, Patricio Pérez M.2, Esteban Pizarro A.3 y Ximena Muñoz A.3

From May 1976 to 1978, 25 hoggests without helmtth treatment were examined every 14 days, for strongylids egg counts to determine the pattern of annual egg output in a Mediterranean environment. The parastte burdens observed by necropsy and throught fecal egg oounts were low. It was fesible to determine annual egg pattern which began with a progressive increase in summer, followed by an important rise during the fall with a peak in April or May. In winter egg output was iow and a seoond increase was observed again in spring. Nematodirus sp had its highest relative frequency during summer. The species found in the necropsie were: Ostertagia spp, Cooperia spp, Trichostrongilus spp, Nematodirus spp and Trichuris ovis.

Keywords: strongylids. eggs output, pattern, hoggests.
1 Estación Experimental La Platina (INIA), Casilla 439, Correo, Santiago.
2 Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Casilla 2. Correo 15. Santiago. Chile.
3 Servicio Nacional de Salud, Talca, Chile.