VPA 211: General Veterinary Parasitology and Helminthology (3+1)

ONCHOCERCA GIBSONI

Host

• Cattle

Location

• Brisket and the external surface of hind-limbs

Morphology

• Male 30-53 mm long and the female 140-190 mm long
• Tail of the male is curved ventrad; it bears small lateral alae and six to nine papillae on either side
• The spicules 0.14-0.22 mm and 0.047-0.094 mm respectively

Intermediate host

• Culicoides pungens

Life cycle

• The life cycle of the onchocerca spp. is typically filarioid, with exception that the microfilariae occur in the tissue spaces of the skin, rather than in the peripheral bloodstream

Diagnosis

• Depends on the finding of microfilariae in skin biopsy samples

Treatment

• Diethylcarbamazine

Control

• Use of microfilaricides
• Reduce the numbers of infected flies