Inside the eye, fluid is constantly produced and drained away. This fluid maintains the eye’s shape and provides nutrients to internal structures.
Glaucoma develops when this drainage system fails. Fluid builds up, increasing pressure within the eye. As pressure rises, it damages the optic nerve and retina which are structures essential for sight. Without rapid treatment, this damage can become irreversible.
Normal eye pressure in dogs typically ranges between 10 and 25 mmHg, so levels above this are considered abnormal.
Primary glaucoma occurs due to an inherited abnormality in the eye’s drainage angle. It is usually passed from parent to puppy.
It often starts in one eye but commonly affects both over time.
There are two forms:
Certain breeds are genetically predisposed (see below).
Secondary glaucoma occurs when another eye condition blocks fluid drainage. It can affect any breed and may involve one or both eyes.
Common underlying causes include:
The outlook depends largely on how well the underlying problem can be managed.
Seek veterinary attention immediately if:
Glaucoma can cause blindness very quickly, sometimes within hours, so prompt treatment is critical.
Your vet will measure eye pressure using a device called a tonometer. This gently touches the eye’s surface to obtain a reading.
Additional testing may include:
Identifying whether the glaucoma is primary or secondary helps guide treatment.
If pressure is very high, hospitalisation may be necessary.
Treatment focuses on:
Specialist referral may be advised if pressure cannot be controlled quickly.
After stabilisation, most dogs require lifelong medication. This often involves multiple eye drops given several times daily.
Regular rechecks are essential to monitor pressure and adjust treatment as needed. Strict adherence to medication timing significantly improves control.
If medication fails to control pain or the eye is already blind, surgical removal of the eye may be recommended.
Although this can be difficult for owners to consider, it is often the most humane option when the eye is painful and vision cannot be restored. Most dogs adapt remarkably well, particularly if vision loss occurred gradually.
Initially, medication may control pressure successfully. However, over months or years, treatment often becomes less effective. Many dogs eventually lose vision in both eyes.
The outcome depends on the underlying cause. If that cause can be treated effectively, pressure control may be more successful.
While any dog can develop secondary glaucoma, certain breeds are more prone to inherited (primary) glaucoma.
Breeds commonly associated with closed-angle glaucoma include:
Open-angle glaucoma is more frequently seen in:
Responsible breeding programmes screen at-risk dogs to reduce inherited cases.
Managing glaucoma can be expensive due to:
If you’re able to, consider pet insurance while your dog is young and healthy to help with unexpected illness or injury. If your dog becomes unwell, talk openly with your vet about the options, the likely costs, and what feels manageable for you. Together, you can tailor a plan that’s right for your dog and your situation.
Dogs that lose vision gradually often adjust very well as they rely heavily on scent, memory, and hearing.
Helpful adjustments include:
With support and patience, most blind dogs continue to enjoy a good quality of life.
