what is the emergency treatment protocol for acute glaucoma in dogs to preserve vision?

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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. 13 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. 4 First-line emergency IOP reduction is achieved with osmotic diuretics — mannitol or glycerol — administered in combination with topical and systemic agents. 1 The goals are rapid IOP lowering and maximum preservation of remaining vision. 3 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. 8 After administration of bimatoprost 0.03% in acute primary glaucoma, IOP decreases by 15–20 mmHg within 45–60 minutes. 1 Prostaglandin analogs work by increasing uveoscleral outflow, which contributes 15% of aqueous drainage in dogs. 1 These agents are applied every 12 hours; increasing frequency beyond q12h does not increase efficacy. 1 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. 814 Dorzolamide 2% is frequently combined with timolol 0.5% as a combination product. 8 Topical CAIs carry a risk of keratitis in dogs, and reversible keratoconjunctivitis sicca and blepharitis have been reported with topical dorzolamide use. 14 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. 14 Timolol 0.5% ophthalmic solution is used as an aqueous humor production suppressor, most often in combination with dorzolamide. 8 Systemically administered ocular antihypertensive agents are used infrequently