Gastrointestinal nematodes (Nematoda: Trichostrongyloidea) in cattle (Bos taurus), moose (Alces alces) and roe deer (Capreolus capreolus) in southern Norway. The effect of anthelmintic treatment in relation to a possible cross-infection.

Abstract

The presence of gastrointestinal nematodes is considered to be a problem in domestic cattle, and various studies have tried to present reasons for and solutions to this problem. A study was conducted in Southern Norway in order to examine whether anthelmintic treatment in cattle is adequate and to investigate if wild cervids like moose and roe deer should be considered as a reservoir for nematode parasites in cattle. The results showed that egg output from cattle was low, which together with low abundance and nematode species diversity in abomasa studied, indicate a low parasite burden in the cattle. It also showed that egg output was significantly correlated with date and days spent on pasture, thus showing a seasonal trend in nematode egg output, although the increase in summer was small and slow, and there was no increase immediately after turnout. This suggests absence of hypobiosis in these cattle. The nematode species fauna was not notably overlapping in cattle, and moose and roe deer. Species found include Ostertagia ostertagi and Trichostrongylus axei in cattle, O. antipini, O. lyrataeformis, Spiculopteragia dagestanica and S. boehmi in moose, and O. antipini, S. boehmi and T. axei in roe deer. The results lead to the assumption that the treatment in cattle is sufficient in keeping the gastrointestinal nematodes at an acceptable level, and that wild cervids pose no major threat to the welfare of domestic cattle. However, more extensive studies are needed to reconfirm these results.