Progressive Retinal Atrophy (PRA)

Progressive retinal atrophy is not a single disease but a group of inherited conditions affecting the photoreceptor cells (rods and cones) in the retina. The rods - responsible for low-light vision - are typically affected first. As the condition progresses, cone function also deteriorates, leading to complete blindness.

PRA is genetic. Different forms affect different breeds, and multiple mutations have been identified. DNA tests are available for many breed-specific forms, allowing carriers to be identified before breeding, and allowing affected dogs to be identified early.

Progression

The rate of progression varies by the specific mutation and breed:

• Night blindness first: Dogs find it harder to navigate in dim light; may be reluctant to go out at dusk, hesitate at the top of stairs in low light, or bump into objects in unfamiliar dim environments
• Gradual day vision loss: Over months to years, vision in normal light also deteriorates
• Complete blindness: The eventual outcome in all affected dogs; the timeline varies from a few months to several years

Most dogs adapt well to vision loss - particularly when it develops gradually and the home environment remains consistent.

What to observe monthly

Low-light navigation. Note whether your dog is hesitant in low light, bumps into objects at dusk or in an unlit room, or changes behaviour in dimly lit environments.

Pupil response. PRA often causes a pronounced tapetal reflection (eyeshine) and dilated pupils due to reduced retinal sensitivity. Your vet will assess this formally, but owners sometimes notice unusually bright eye shine in photographs.

General navigation. Note any hesitation, bumping into objects, or changes in confident, free movement - particularly in unfamiliar environments.

Cataract development. Secondary cataracts develop in some dogs with PRA as the retinal degeneration progresses. The lens may appear cloudy.

Response to changes in the environment. Dogs adapting to progressive vision loss often rely more heavily on memory of their home environment. Rearranging furniture or visiting unfamiliar places may reveal vision limitations.

DNA testing

DNA tests for PRA mutations are available through commercial veterinary genetics laboratories. Testing requires a cheek swab or blood sample. Tests identify whether a dog is:

• Clear: No copies of the mutation
• Carrier: One copy (for recessive conditions - typically no disease, but can pass the mutation to offspring)
• Affected: Two copies - will develop PRA

DNA testing is available for PRA mutations in: Miniature Schnauzer (PRA3), Cocker Spaniel (cord1-PRA), Labrador Retriever (prcd-PRA), Golden Retriever (prcd-PRA), Border Collie (rcd2-PRA), and many other breeds. Speak to your vet about which test applies to your breed.

Management

There is currently no treatment that stops or reverses PRA. Management focuses on supporting a dog as they adapt to progressive vision loss:

• Maintain a consistent home environment - don't rearrange furniture
• Use scent and textural cues on routes (e.g., a rough mat at the top of stairs)
• Verbal cues and consistent communication become more important as vision decreases
• Avoid off-lead exercise in unfamiliar or hazardous environments as vision declines
• A halo device (a hoop attached to a harness) can prevent collision with obstacles for dogs with significant vision loss

When to contact your vet

Contact your vet for a routine assessment if:

• You're noticing signs of night blindness or reduced vision
• You have a breed at risk and want DNA testing or a BVA/KC eye scheme assessment
• Secondary cataracts may be developing

Frequently Asked Questions

Can PRA be treated? Currently no treatment stops or reverses PRA. Research into gene therapy is ongoing, with some promising results in specific mutations. For now, management is supportive.

My dog has been DNA tested as a carrier - does that mean they'll go blind? Carriers of a recessive PRA mutation carry one copy of the mutation but typically do not develop the disease. They can pass the mutation to their offspring if bred with another carrier or affected dog. Carriers should not be bred with other carriers - breeding with a DNA-clear dog prevents affected offspring.

How do blind dogs cope? Generally very well, particularly when the vision loss is gradual - dogs have time to memorise environments and adapt. Smell, hearing, and spatial memory compensate significantly. Most owners are surprised by how well their dog navigates and maintains quality of life after becoming completely blind.

Should I have my dog's eyes tested even if they seem fine? For breeds at significant risk of PRA, annual BVA/KC eye scheme assessments detect early signs of retinal change before clinical vision impairment is apparent. This allows earlier preparation and, for breeding dogs, informs breeding decisions.

What is the BVA/KC Eye Scheme? A voluntary health scheme jointly run by the British Veterinary Association and Kennel Club. Ophthalmologists examine the eyes and grade findings. Results are used by breeders to reduce the prevalence of hereditary eye conditions. For at-risk breeds, eye scheme certification is part of responsible breeding.