Five desert sheep were exposed to 5000 or 10000Schistosoma boviscercariae each, and the parasitological, clinical and pathological parameters were recorded. The pre-patent period was approximately 7 weeks and from that time onwards, the animals became progressively ill and emaciated. Following necropsy at the 12th week, a percentage schistosome recovery ranging from 36%—63.6% was found, and there were high egg densities in the intestinal tract and the liver. These organs revealed severe pathological lesions which were described in detail along with the changes occurring in other tissues.