Prevalence and pathology of warble fly larvae (Stroviloestrus vanzyli) among Kafue lechwe (Kobus leche kafuensis)

The Kafue lechwe (Kobus leche kafuensis) is a semi- aquatic antelope, endemic to Zambia and occurs in one large population on the Kafue flats of the Kafue river where cattle mingle and share the water and pasture with them during dry season for a period of about 6 months every year from May to October. Out of 177 Kafue lechwe examined for the presence of warble larvae in the subcutaneous tissues by palpation, 36 (20%) had warble fly larvae ranging from 12–194. The younger animals had more larvae than older one. The nodule were small, subcutaneous swelling containing white to cream colour warble larvae in different stages of development. Histo-pathological lesions were characterised by chronic granulomatous reaction. Mononuclear cells containing large eosinophilic granules were seen and resembled globule leucocytes. Masses of leucocytes were present in the mid gut of the larvae. No lesions or larvae could be seen in histopathological sections of spinal cord and oesophagus. Massive infestation by the larvae may result in poor and emaciated condition of the lechwe and may predispose the host to other infections.