The emergency protocol for acute canine glaucoma prioritizes immediate intraocular pressure (IOP) reduction using osmotic diuretics combined with topical and systemic drugs, with urgent referral to a veterinary ophthalmologist. MSD Vet Manuals+1
Normal IOP is <20 mmHg; acute glaucoma warrants immediate intervention. Affected dogs may present with IOP as high as 55 mmHg, accompanied by episcleral injection, diffuse corneal edema, and a dilated pupil. MSD Vet Manuals
First-line emergency IOP reduction is achieved with osmotic diuretics — mannitol or glycerol — administered in combination with topical and systemic agents. MSD Vet Manuals The goals are rapid IOP lowering and maximum preservation of remaining vision. MSD Vet Manuals
Topical prostaglandin analogs are a critical component of the acute protocol in dogs. Latanoprost 0.005% is the most widely used agent in this class. Veterinary Opht… After administration of bimatoprost 0.03% in acute primary glaucoma, IOP decreases by 15–20 mmHg within 45–60 minutes. MSD Vet Manuals Prostaglandin analogs work by increasing uveoscleral outflow, which contributes 15% of aqueous drainage in dogs. MSD Vet Manuals These agents are applied every 12 hours; increasing frequency beyond q12h does not increase efficacy. MSD Vet Manuals
Topical carbonic anhydrase inhibitors (CAIs) — dorzolamide 2% and brinzolamide — are first-line aqueous humor suppressors and among the most commonly used agents in canine glaucoma management. Veterinary Opht…+1 Dorzolamide 2% is frequently combined with timolol 0.5% as a combination product. Veterinary Opht… Topical CAIs carry a risk of keratitis in dogs, and reversible keratoconjunctivitis sicca and blepharitis have been reported with topical dorzolamide use. Journal of the… Systemic adverse effects including metabolic acidosis and hypokalemia have been reported with topical CAI use in cats; dogs appear less susceptible but monitoring is warranted. Journal of the…
Timolol 0.5% ophthalmic solution is used as an aqueous humor production suppressor, most often in combination with dorzolamide. Veterinary Opht… Systemically administered ocular antihypertensive agents are used infrequently in acute management. Veterinary Opht…
Immediate referral to a veterinary ophthalmologist is indicated for advanced diagnostics and to institute definitive medical or surgical treatment. MSD Vet Manuals Medical therapy alone frequently fails within months, leading to uncontrolled IOP and blindness, making early surgical planning essential. Veterinary Opht…
If medical management fails, surgical options include cyclophotocoagulation (CPC) and gonioimplantation. Transscleral CPC achieves IOP control in 60–92% of dogs at 8–12 months, with vision preservation in 50–53%. Veterinary Opht… Endoscopic CPC achieves IOP control in 81–85% and vision preservation in 72–74% at one year. Veterinary Opht… Ahmed glaucoma valve implantation yields a mean post-surgical vision preservation duration of 57.5 months across all causes of glaucoma. Veterinary Opht…
| Drug/Intervention | Dose or Protocol | Efficacy | Key Caveat |
|---|---|---|---|
| Mannitol or glycerol (osmotic diuretic) | IV/PO per standard protocol | Emergency IOP reduction | Use in combination with topical agents MSD Vet Manuals |
| Latanoprost 0.005% | Topical q12h | Increases uveoscleral outflow (15% of drainage) | Ineffective in cats (uveoscleral = 3%) MSD Vet Manuals |
| Bimatoprost 0.03% | Topical q12h | 15–20 mmHg IOP reduction in 45–60 min | Increasing frequency beyond q12h adds no benefit MSD Vet Manuals |
| Dorzolamide 2% ± timolol 0.5% | Topical q8–12h | Most commonly used aqueous suppressor combination | Risk of keratitis, reversible KCS, blepharitis in dogs Veterinary Opht…+1 |
| Transscleral CPC | Surgical | IOP control 60–92% at 8–12 months; vision preservation 50–53% | Variable long-term success Veterinary Opht… |
| Endoscopic CPC | Surgical | IOP control 81–85%; vision preservation 72–74% at 1 year | Veterinary Opht… |
| Ahmed glaucoma valve | Surgical | Mean vision preservation 57.5 months | American Cocker Spaniels have shorter PVP (33.7 months) vs. other breeds Veterinary Opht… |
Would you like guidance on the prophylactic treatment protocol for the normotensive fellow eye in a dog with unilateral primary glaucoma?