Evidence of onchocerciasis in Georgia cattle: prevalence at slaughter

In the study for an animal model of onchocerciasis, particularly one dependent on a Simulium vector, the prevalence of Onchocerca lienalis in Georgia cattle was assessed. In 7 collections of cervical and umbilical skin samples and nuchal ligaments made between April and December, 1975, adult parasites were found in fascia of the ligamentum nuchae of 62 of 124 animals (50.0%), and microfilariae were present in 1 or more of the skin samples from 85 to 124 cattle (68.6%). Infections occurred in cattle of all ages examined (from 2 to more than 10 years). Microfilariae were found more frequently and abundantly in umbilical than in cervical skin. They were present in 47 of 62 cattle in which adult nematodes occurred, but also present in 38 of 62 cattle in which no adult nematodes were discovered. The adult nematodes caused considerable inflammation in the fascial sheath of the ligamentum muchae.