Subconjunctival filariasis due to Onchocerca sp. in dogs: report of 23 cases in Greece.

In the present study, we describe a series of 23 cases of ocular subconjunctival parasitic granulomas in dogs, admitted to the Clinic of Surgery, Faculty of Veterinary Medicine of the Aristotle University of Thessaloniki, Greece, between 1997 and 2000. The ophthalmic manifestations in all animals were periorbital swelling, discomfort, photophobia, conjunctival congestion, and discharge. A more detailed examination revealed the presence of periocular masses (nodules) on the subconjunctival bulbar space. Granulomatous or cyst-like formations were extracted surgically, and were found to contain thread-like nematode parasites. A histologic and parasitologic examination of tissues and parasites was carried out. Diagnosis of parasitic granulomas was made and the parasite was identified as Onchocerca sp. This is the largest series of cases reported of aberrant Onchocerca infections in dogs coming from one geographic location.