Ophthalmic abnormalities secondary to periocular or ocular snakebite (pit vipers) in dogs--11 cases (2012-2014)

Abstract

Objective: To describe ophthalmic abnormalities secondary to periocular and ocular snakebite in dogs.

Animal studied: Retrospective review of medical records from dogs presenting to the Small Animal Hospital at University of Florida following snakebites to the face (2012-2014). Two groups were identified: periocular bites (PB) and ocular bites (OB).

Results: Records from eleven dogs matched the search criteria and were included in the study (PB=9, 81.8%; OB=2, 18.2%). Both OB cases involved the cornea. Facial edema, blepharospasm, chemosis, and conjunctival hyperemia occurred in all cases (100%). Hemorrhage from the eyelids occurred in eight cases (72.7%; PB=7, OB=1). Subconjunctival hemorrhage occurred in seven cases (63.6%; PB=6, OB=1). Third eyelid laceration and nictitans gland prolapse occurred in 1 case each (9%; PB=1). Lagophthalmia was present in three cases (27.3%; PB=3), with secondary corneal ulcer in two cases (18.2%; PB=2). Corneal ulcer due to direct corneal bite occurred in two cases (18.2%-partial thickness with melting (1) and full thickness (1) ). Uveitis was present in 6 cases (54.5%; PB=4, OB=2), with flare and miosis in 4 cases (36.4%; PB=2, OB=2). Hyphema, fibrin in anterior chamber, and cataract occurred in one case (9%; OB=1). Vision loss occurred in two cases (18.2%; PB=2), secondary to retinal degeneration (PB=1) and amaurosis (PB=1). Mean follow-up time was 7 weeks (range: 3 days-11 months). Most clinical signs had resolved by last examination.

Conclusions: Periocular symptoms were more commonly observed than ocular alterations, regardless of bite location. Appropriate supportive therapy should be instituted according to clinical signs.

Keywords: dog; envenomation; eye; ocular; pit viper; snakebite.