Distribution of Onchocerca spp. microfilariae in the dermis of cattle.

A grid was drawn on a lateral half of 10 hides, from cattle infected with both Onchocerca gutturosa and Onchocerca lienalis, which were obtained from an abattoir in central Florida. Paired 7-mm diameter skin cores were taken from 24 grid sites on each hide and microfilariae (mff) extracted to determine their distribution. The only consistent pattern distribution was that mff were recovered from all 10 hides at four sample sites along the ventral midline near the umbilicus. Microfilariae were also frequently found in large numbers along the dorsal cervical midline and in the region of the tarsal and carpal-metacarpal joints.