Collie Eye Anomaly in Dogs

CEA is an autosomal recessive condition. This means that both parents must be carriers to produce affected offspring, but unaffected dogs may be carriers of the trait or have mild symptoms. Some dogs have severe visual impairment or complete blindness.

Breeding programs have been in place for over 50 years which have successfully lowered the number of affected dogs.

Prompt veterinary care is advised for dogs with symptoms consistent with CEA. Cases of sudden blindness are considered an emergency.

CEA is a genetic mutation where an estimated 65-90% of Collie breeds can be possible carriers.

Collie Eye Anomaly (CEA) is a common condition in collie breeds such as:

• Border collie
• Smooth collie
• Rough collie
• Shetland sheepdog
• Lancashire heeler
• Australian shepherds

Each of these issues can result in varying levels of vision loss and blindness.

Some cases of CEA become painful due to retinal detachment resulting in persistent bleeding into the eye, or increased pressure inside the eye (glaucoma).

Symptoms of glaucoma include

• Rubbing at the eyes
• Obvious bulging of one or both eyes
• Red eye(s)
• Persistent blinking or squinting (blepharospasm)

CEA is caused by a genetic mutation present in collie and sheepdog breed groups. The mutation results in abnormal development of the blood vessels that supply the light-sensitive layer of the eye (the retina).

Symptoms of CEA include

• Small pupils
• Uneven pupils (anisocoria)
• Light sensitivity
• Smaller eyeball (microphthalmia)
• Sunken eyeball (enophthalmia)
• Poor vision or total blindness
• Bumping into objects
• Poor depth perception

CEA affects both eyes but may affect them to differing degrees. If only one eye is affected, vision loss may be less obvious.

Diagnosis of CEA involves an eye examination, usually with a board-certified veterinary ophthalmologist.

Direct treatment of CEA is not possible, but management of secondary complications includes:

• Eye drops to maintain normal eye pressures, and to reduce inflammation and pain
• Laser eye surgery to treat retinal detachment

CEA is a lifelong condition in dogs. Prognosis varies depending on the extent of symptoms. Some forms of CEA are mild and symptoms do not progress or worsen. Other forms result in progressive visual impairment. Complete blindness occurs in some dogs and is irreversible; however, with appropriate lifestyle management, most dogs cope well with blindness.

Prevention focuses on selective breeding programs and involves:

• Blood test for the specific genetic mutation
• Ophthalmic examination by a board-certified ophthalmologist

Recommendations for frequency of examination vary, but generally include:

• Screening at 6-8 weeks old in at-risk puppies
• Follow-up at 6-12 months old
• Eye examinations prior to breeding
• Examination of any dogs that develop symptoms

Dogs with CEA should not be bred.

CEA mutation is very common in collie breeds. Prevalence varies, but prior to initiation of the breeding programs 50 years ago, up to 90% of collies carried the mutation. Current prevalence is unknown, but the number of affected dogs is much lower.

• Topical eye drops
• Laser eye surgery
• Lifestyle management of vision loss