Epizotiología de las infestaciones por Trichostrongylidae en los ovinos de León

Abstract

After a previous revision of bibliography on taxonomy, methodology and epizootiology, we have studied some epizootiologic factors of infestation by Trichostrongylidae in ovins in León (Spain), starting with material proceeding from slaugter-house collected during one year and through coprologic analyses also carried out during one year on a typical herd in the province of León.

Parasitism is very frequent (97,9 % ) but the average extent of its infestation is not very high (822 worms per animal); animals one to two years aged are tbe most affected.
The commonest species are: Ostertagia (Osteragia) circumcincta, O. (O) trifurcata, Tri­chostronylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis y N. spathiger.

ln epizootiology we have observed a seasonal tendency with more intense infestalions from january to april and from june to September. Likewise, the elimination of eggs from excre­ments reaches its maximum in Spring, being slightly lower at the end of Summer, and it is of very little importance at the end of the year.
We propose an interpretation of the epizootiology of the infestation caused by trichos­trogylidae, by coordinating the available data on geoclimatology and those concerning the rela­tion parasite-guest.