Prevalence of Gasterophilus larvae (Diptera: Gasterophilidae) in slaughter horses in North-Eastern Germany

Stomach and duodenum of 620 horses slaughtered between January 1996 and April 1997 originating most from the Federal States of Brandenburg and Mecklenburg-Vorpommern were examined for Gasterophilus larvae. 47.9 per cent of the horses harboured Gasterophilus larvae in their stomachs. A total of 12,886 larvae were collected belonging exclusively to the species G. intestinalis. The intensity of infestation showed a great individual variation, ranging from some to more than 400 larvae. Second-stage larvae were recorded from September to March, third-stage larvae from October to July, in one case even in August. Maximal larvae counts were recorded from December to April. Compared to a study conducted 20 years ago in the same region, a considerable increase of the prevalence of G. intestinalis was found, while the intensity of infestation remained nearly unchanged.