Ocular Onchocerca infections in two dogs in western United States

Two dogs, one from California and one from Arizona, were found to have aber rant infections caused by filarial nematodes of the genus Onchocerca. In bo th cases, the parasites are localized in or near the eye. In one case the w orm was located in the cornea and was surgically removed. In the second cas e, a very marked granulomatous reaction was induced in the retrobulbar spac e, mimicking an abscess. This eye was enucleated. The worms in both instanc es were female, and were gravid, i.e. contained microfilariae in utero, ind icating that a male worm(s) had been present and mating had occurred. The e xact identity of the species of Onchocerca responsible cannot be determined , although the features observed are most like Onchocerca lienalis of cattl e. These cases represent the fourth and fifth such cases reported from the US, and are especially interesting because of the unusual location of the w orms, the small number of recognized cases, and the similarity to a recent zoonotic human infection. Published by Elsevier Science B.V.