PREVALENCE OF DICROCOELIUM-DENDRITICUM INFECTION IN SHEEP IN LEON PROVINCE (NW SPAIN)

A coprological survey was carried out between October 1992 and May 1993 in the sheep population of Leon province (NW Spain) to estimate the prevalence of Dicrocoelium dendriticum infection. Seven hundred and sixty seven faecal samples from sheep over 1 year of age from 152 randomly selected flocks of the nine Leon province livestock areas (grouped in the four natural regions) were recovered and analysed using a sedimentation method. Results showed a mean individual sample prevalence of 26.7% and a mean flock prevalence of 47.4%. Mixed infections with Fasciola hepatica were found in 3.7% of animals. The median of D. dendriticum eggs per gram in faeces was 20 and ranged from 5 to 578. A significant association was found between D. dendriticum infection and geographical location with the existence of higher prevalences in northern livestock areas (Mountain region) when compared with other areas in the province. On the other hand, no significant association between trematode infection and flock size or anthelmintic programmes used were found. Several factors such as climate and poor health and husbandry systems are suggested as being related to increasing infection prevalence.