| alveolar mastocytosis and eosinophilia in lambs with naturally acquired nematode infections of protostrongylus rufescens and haemonchus contortus. | specific-pathogen-free dorset and st. croix lambs were placed on pasture contaminated with haemonchus contortus third stage larvae and slugs carrying third stage larvae of protostrongylus rufescens for an entire grazing season to evaluate breed differences in acquired resistance to these nematodes. lambs were evaluated for clinical signs, clinical pathology and histopathologic lesions associated with these infections. both breeds acquired natural infections with h. contortus and lungworm when al ... | 1995 | 8746699 |