Anticollagenase Therapy for Canine Corneal Ulcers: A Narrative Review of Mechanisms, Efficacy, and Clinical Implementation

BACKGROUND: Corneal ulceration in dogs is frequently complicated by proteolytic enzyme activity, including matrix metalloproteinases and collagenases, which accelerate stromal degradation and may progress to corneal perforation. Antimicrobial therapy alone addresses the infectious component but does not arrest enzyme-mediated tissue destruction, suggesting the need for adjunctive anticollagenase treatment. OBJECTIVE: This review evaluates current and emerging anticollagenase therapies for canine corneal ulceration, summarizing their mechanisms of action, efficacy, and practical considerations for clinical application. SOURCES OF DATA: Peer-reviewed experimental, clinical, and translational studies in veterinary and comparative ophthalmology were examined to identify clinically relevant evidence related to anticollagenase use in dogs. SUMMARY OF FINDINGS: Several anticollagenase agents have been described as having potential anticollagenase activity, including N-acetylcysteine, ethylenediaminetetraacetic acid, tetracyclines, and blood-derived products such as autologous serum. Available evidence suggests that these agents may help moderate stromal degradation when used alongside appropriate antimicrobial therapy, though the quality and quantity of supporting data vary widely. Practical considerations include formulation feasibility, compounding stability, frequency of administration, and known or theoretical safety concerns. Emerging agents and alternative approaches show potential but require further clinical validation in veterinary patients before their clinical roles can be clearly defined. CONCLUSIONS: Anticollagenase therapy may offer adjunctive benefit in the management of canine corneal ulcers, particularly in cases where proteolytic activity is suspected to contribute to disease progression. However, current evidence remains limited and heterogeneous, and further controlled clinical studies are required before definitive recommendations can be made regarding the selection or prioritization of specific agents.