Treatment outcome of spontaneous chronic corneal epithelial defects in brachycephalic dogs comparing Boxers and non-Boxers: A retrospective multicenter study of 420 dogs.

Objective: To compare characteristics and treatment outcomes of spontaneous chronic corneal epithelial defects (SCCEDs) in brachycephalic non-Boxers and Boxers. We hypothesized that brachycephalic non-Boxers develop SCCEDs at a younger age and develop complications more frequently than Boxers.

Animals Studied: Retrospective review of medical records of brachycephalic dogs treated for SCCEDs between January 2018 and December 2022 in multiple ophthalmology referral centers in the UK.

Procedure: Data recorded included breed, age, time of onset, treatment prior to referral, treatment at referral, time to heal, need for further procedures, and complications.

Results: A total of 464 SCCEDs in 420 dogs were included composed of 173 Boxers with 200 SCCEDs and 247 brachycephalic non-Boxer dogs with 264 SCCEDs. Boxers were significantly older (median 8.2, range 4.5-12.7 years) than brachycephalic non-Boxers (median 7.2, range 1.6-15.9 years) (p < .001). The first treatment (cotton-tipped applicator [CTA] debridement, diamond burr debridement, superficial keratectomy, grid keratotomy, punctate keratotomy, or combinations of these) selected was significantly different between groups (p < .001). Healing, excluding cases addressed by CTA debridement, following the first procedure was significantly more successful in Boxers (p = .049). Excluding cases addressed by CTA debridement, 9.6% of SCCEDs in Boxers (20/200) and 13.4% (32/239) of non-Boxers required more than one procedure. In the non-Boxer group, 9.5% (25/264) developed complications, contrasting with 4% (8/200) in the Boxer group. Non-Boxers were more likely to develop complications after the first treatment (p = .006).

Conclusion: Non-Boxer brachycephalic dogs develop SCCEDs younger than Boxers. This study suggests SCCEDs in brachycephalic non-Boxers may be less likely to heal following one mechanical treatment and are more likely to develop complications.