Canine ocular onchocerciasis: a retrospective review of the diagnosis, treatment, and outcome of 16 cases in New Mexico (2011-2015).

OBJECTIVE

To describe the clinical exam findings, treatment and outcomes of 16 dogs diagnosed with ocular onchocerciasis in New Mexico.

METHODS

Records of dogs diagnosed by the primary author were reviewed (2011-2015). Records that were accessible and included a diagnosis of Onchocerca lupi by histopathologic or molecular identification of the nematode were included.

RESULTS

Sixteen cases were included. 3/16 dogs were treated with year-round heartworm prophylaxis prior to infection. Clinical exam findings included conjunctival hyperemia and/or episcleral injection (16/16), focal subconjunctival mass(es) (14/16), retinal detachment (7/16), corneal edema (4/16), chemosis (3/16), corneal opacity (2/16), exophthalmia (1/16), glaucoma (1/16), strabismus (1/16), blepharospasm (1/16), and vitreal degeneration (1/16). Ocular involvement was unilateral in 7/16 dogs and bilateral in 9/16 dogs. The diagnosis was confirmed via histologic identification of the nematodes and/or PCR. Treatment consisted of medical management or a combination medical and surgical management. Known or suspected recurrence of disease was documented in 10 dogs.

CONCLUSIONS

Canine ocular onchocerciasis is endemic in New Mexico. Histopathology and molecular identification are useful diagnostic tools. Medical management alone was successful in many cases.