Intraocular Parafilaria bovicola infection and surgical removal in a mixed breed heifer

An approximately 1.5-year-old mixed breed heifer was presented for evaluation and treatment due to ocular pain affecting the right eye secondary to a live nematode within the anterior chamber. Ophthalmic examination revealed marked blepharospasm, evidence of chronic keratitis, uveitis, and a single, white, approximately 2.5 cm long, 0.5 mm thick, living parasite. The heifer underwent general anesthesia, and the parasite was removed using passive aqueous humor outflow following a stab incision into the anterior chamber. Twenty-four hours after removal of the intraocular parasite, the heifer displayed a significant improvement in ocular comfort, corneal edema, and uveitis. The nematode was identified via genetic analyses as Parafilaria bovicola, a filarial parasite of cattle. The heifer was discharged 5 days following nematode removal with a marked improvement in all ocular signs and apparently normal vision. To the authors' knowledge, there are no previous reports of confirmed intraocular filariosis caused by P. bovicola in the veterinary literature, nor are there reports detailing surgical removal of intraocular parasites in bovids.