Diagnosis of mange in West African Dwarf (WAD) and Red Sokoto (RS) goats

The diagnosis of mange is problematic in the absence of mites in skin scrapings because many skin diseases present similar gross features as mange. The study evaluated the stepwise procedure for herd diagnosis of mange in the West African Dwarf (WAD) and Red Sokoto (RS) goats with greater specificity and sensitivity. Twenty-seven WAD goats (n = 27) and forty RS goats (n = 40) goats with mange-like skin lesions (alopecia, scabs, crusts, and scratch injuries) out of a total herd population of 114 WAD goats and 317 RS goats respectively in Nsukka, Eastern Nigeria, were examined by directed sampling method. Skin scrapings and biopsies were collected from the goats and processed using standard procedures. The skin scrapings revealed Sarcoptes scabiei in 7 out of 27 WAD goats with mange-like gross lesions and Psoroptes spp. together with lice (Linognathus spp.) and their eggs in 2 out of 40 RS goats with mange-like gross lesions. Histopathological studies showed that 12 out of 27 WAD goats and 2 out of 40 RS goats with mange-like gross lesions had microscopic features highly suggestive of mange; in other words, the prevalence of mange was 44.4% in WAD and 5% in RS goats. The negative samples were diagnosed as fungal infections, neoplasms, nonspecific dermatitis, and dermatoses. The combination of directed sampling by gross appearance, a parasitological study of skin scrapings, and histopathological features of the skin biopsies were used to increase the sensitivity and specificity of mange diagnosis.