Pathology and clinical manifestation of epizootic lymphangitis in cart mules in Ethiopia

Abstract

The distribution and clinical lesion type of epizootic lymphangitis (EL) were investigated on 65 EL cases of cart-mules. Clinical, microscopic, histopathological, and mycological examinations were used. The proportion of cutaneous lesion was 92.3% (60/65) while only 4.6% (3/65), and 3.1% (2/65) had pulmonary and ocular lesions, respectively. The cutaneous lesions were characterized by suppurative multi-focal dermatitis and lymphangitis, which appeared as nodules or ulcers. The scrotal and axillary regions and the fore and hind legs were frequently involved while the neck and facial regions were less frequently involved. The pulmonary form was serious by causing dyspnoea, which lead to death. Unilateral ulcerating conjunctivitis with purulent ocular discharge was also observed. Hematoxylin-eosin stained histological section showed pyogranulomatous inflammation with fibroplasia. Therefore, once a mule is infected, the distribution and clinical lesion type of EL are with those in horses.