Abstract
Lungworm infections are known to be frequent and responsible for substantial economic losses in ruminants. They are caused by Dictyocaulus filaria and various species belonging to the Protostrongylidae family of nematodes. This present study was conducted at the Tiaret municipal slaughterhouse and the parasitology laboratory of the veterinary institute for six months, from November 2016 to April 2017. The study aimed to evaluate the occurrence of lungworm infections and the determination of the circulating species affecting sheep in the region with a pathological study of infected pulmonary tissue sections. The overall incidence of the pathology in sheep was 26 % (240/921). The identified species were Muellerius capillaris 43 %, Neostrongylus linearis 8 %, Cystocaulus ocreatus 4 %, Dictyocaulus filaria 3 %, Protostrongylus rufescens 1 %, and mixed infestations 42 %. The histological examination of corresponding lesions has revealed pneumonia-type, and bronchopneumonia, inflammatory lesions, with a predominance of mononuclear cells, necrosis of bronchial epithelium, and pulmonary parenchyma as well as hyperplasia of the bronchiolar epithelium. Prevention and control of these parasites is therefore essential for releasing the potential of sheep production.