Very common in Northern Cameroon, wherever its vector, Simulium damnosum s.l., prevails
Renz, A. (2001): Onchocerciasis, bovine. In: The Encyclopaedia of Arthropod-transmitted infections, M.W. Service ed. CABI Publishing (578 pg). 375-381.
Wahl, G., MD. Achukwi, D. Mba, O. Dawa & A. Renz (1994): Bovine onchocercosis in North-Cameroon. Veterinary Parasitology 52, 297-311.
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Only found, where the vector Simulium bovis is common, i.e. along the river Vina du Nord near Soramboum and Touboro. The nudules are smaller than those of O. ochengi and fixed rather to the carcass of the slaughtered animal than to the skin.
Wahl, G. & A. Renz (1991): Transmission of Onchocerca dukei by Simulium bovis in North-Cameroon. Trop. Med. Parasitol. 42, 368-370
Very common, found in the aorta wall. The microfilariae are the longest found in the skin and show a blunted head.
Hildebrandt, T.: Quantitative Untersuchungen zum Mikrofilarienumsatz im Onchocerca-Knoten bei Afrikanischen Rindern (O. armillata). Thesis of Diploma, Tübingen, 1995.
Very commn, found in the ligamentum nuchae. The mircofilariae are smaller and thinner than those of O. ochengi. Vectors are Ceratopogonids, but the local species is as yet unknown.
Adult worms occasionally seen in small numbers in the abdominal cavity of slaughtered cattle. Mircofilariae are sheeted and circulate in the blood. Vectors are mosquitoes, but the local vector species are still unknown.