Chronic progressive lymphoedema in a Friesian horse: clinical aspects and diagnostic approach - case report

Chronic Progressive Lymphoedema (CPL) is a disabling disease of draft horses that affects lymphatic system function typically in the distal limbs. Deformities of distal limbs, especially of the pastern, with fibrosis and skin nodular lesions are consequences of disease progression. A 15-year-old Friesian stallion presented for evaluation with history of forelimb enlargement and nodule formations distal to the carpus for four years. Simple radiographs showed soft tissue nodular lesions and venous contrasted radiography showed intense enlargement of II common digital palmar vein of both forelimbs. Tissue culture tests revealed Streptococcus equi and Proteus mirabilis isolation and skin scraping test identified Chorioptes bovis mites. Histological examination revealed perivasculitis and lymph vessels distention. History, clinical and histological findings, and complementary exams suggested CPL diagnosis. We were unable to find previously published cases describing this disease in Brazil, where the increasing number of draft horses requires attention to this problem. The correct and early diagnosis substantially delays disease progression. Therefore, we highlight the need for nationwide propagation of these data to ensure better diagnosis and early treatment of future CPL cases.