Glaucoma (Primary, Inherited)
Learn what the condition is, how it may be detected early, how it is treated or managed, and which breeds or species are linked to it.
Condition snapshot
A concise guide to the condition’s pattern, detection, management and urgency.
Emergency presentation is possibleSudden redness, cloudiness, a dilated pupil, eye pain or abrupt visual loss requires emergency assessment.
This snapshot is a general guide, not a diagnosis or treatment plan. New, severe or worsening signs require veterinary assessment.
About the condition
Primary glaucoma is an inherited eye disease in which fluid cannot drain from the eye normally, causing intraocular pressure to rise. The eye continually produces clear fluid called aqueous humour. Under normal conditions this fluid leaves through a drainage angle between the cornea and iris. In glaucoma, drainage resistance increases while fluid production continues, and pressure damages the retina and optic nerve.
Several anatomical forms occur in dogs, including open-angle and angle-closure glaucoma and goniodysgenesis, in which the drainage structures develop abnormally. Different breeds are predisposed to different forms. Primary disease often begins in one eye, but the opposite eye is considered at significant risk because both eyes share the same inherited anatomy.
Glaucoma is painful. Affected dogs may squint, rub the face or become quiet and withdrawn. The eye can look red, cloudy or blue-grey, the pupil may be enlarged and poorly responsive, and the globe can eventually become visibly enlarged. Vision can be lost rapidly when pressure rises sharply. Chronic glaucoma causes irreversible death of retinal ganglion cells and degeneration of the optic nerve.
The rest of the eye is assessed to distinguish inherited disease from secondary glaucoma caused by inflammation, lens luxation, tumour or other ocular disorders.
Glaucoma is one of the most urgent causes of painful vision loss in dogs. Once optic-nerve damage has occurred it cannot be reversed, so preserving sight depends on reducing pressure quickly. Even when vision has already been lost, treatment remains important because an uncontrolled glaucomatous eye can remain severely painful.
Once pressure has damaged the retina or optic nerve, lost vision cannot usually be restored, which makes rapid recognition of a painful red or cloudy eye particularly important.
A single normal reading therefore does not guarantee that glaucoma will not develop later. The aim is to identify anatomical risk or pressure change before irreversible optic-nerve injury has occurred.
Screening & Early Detection
Dogs from breeds predisposed to primary glaucoma benefit from regular ophthalmic examination even when vision appears normal. Tonometry measures eye pressure and can identify an abnormal elevation, although pressure may remain normal between intermittent early episodes.
Gonioscopy is particularly useful in breeds prone to angle-closure disease because it assesses the shape and openness of the drainage angle before clinical glaucoma occurs. A veterinary ophthalmologist may use the result to estimate risk and plan monitoring of both eyes. Routine examination also checks the optic nerve, retina and lens for evidence of other ocular disease.
Treat sudden redness, corneal cloudiness, a dilated pupil, squinting, unexplained eye pain or abrupt visual loss as an emergency. Acute glaucoma can destroy vision in a short period, so waiting until the next routine appointment can permanently reduce treatment options.
When glaucoma develops in one eye and is classified as primary, the fellow eye requires proactive monitoring and may be offered preventive medication. Genetic tests are available for only selected breed-specific forms, so clinical screening remains essential.
Diagnosis requires tonometry to measure intraocular pressure. Gonioscopy allows a veterinary ophthalmologist to examine the drainage angle and can help classify the type of primary glaucoma.
Treatment & Management
Treatment is directed at reducing intraocular pressure and preserving vision when possible. Acute glaucoma is an emergency. Eye drops that decrease aqueous-humour production or improve outflow are started promptly, and systemic medication may be used to lower pressure more rapidly. The response is checked with repeat tonometry because an eye that looks less red may still have damaging pressure.
If vision remains potentially salvageable, a veterinary ophthalmologist may discuss laser treatment of the fluid-producing tissue, drainage implants or other procedures designed to control pressure. The best option depends on glaucoma type, remaining vision and the dog’s overall health. Medical therapy alone often becomes less effective as primary glaucoma progresses.
When an eye is permanently blind and pressure cannot be controlled comfortably, the priority changes from preserving sight to eliminating pain. Surgical options include removal of the eye or procedures that leave a cosmetic globe while preventing continued pressure. Dogs generally adapt very well after removal of a chronically painful blind eye.
The opposite eye needs ongoing preventive care because primary glaucoma is frequently bilateral over time. Pressure-lowering medication may delay onset in the fellow eye in some cases, but it does not remove inherited risk.
Give eye medication exactly as prescribed and attend pressure rechecks. Glaucoma management can change quickly, and persistent pain, renewed cloudiness or visual deterioration should prompt immediate reassessment rather than waiting for a scheduled follow-up.
Breeds or species affected
Afghan hound
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Akita
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Alaskan malamute
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American Cocker Spaniel
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Grand Basset Griffon Vendéen
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Basset hound
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Beagle
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Bedlington terrier
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Border Collie
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Boston terrier
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Bouvier des Flandres
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Brittany
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Cairn terrier
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Chihuahua
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Shar Pei
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Chow chow
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English Cocker Spaniel
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Dachshund
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Dalmatian
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Dandie Dinmont terrier
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English springer spaniel
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Smooth Fox Terrier
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Wire Fox Terrier
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Great Dane
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Keeshond
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Maltese
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Miniature Poodle
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Miniature Schnauzer
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Newfoundland
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Norfolk terrier
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Norwegian elkhound
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Petit Basset Griffon Vendéen
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Poodle (standard)
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Toy Poodle
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Saluki
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Samoyed
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Schnauzer (miniature, standard)
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Sealyham terrier
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Siberian husky
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Springer spaniel
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Welsh springer spaniel
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Welsh terrier
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West Highland white terrier
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