Progressive Retinal Atrophy in Dogs

Category: Eye
Inheritance: Autosomal recessive
Breeds documented: 90
Published sources: 31

Overview

The light-sensing lining at the back of the eye, called the retina, gradually loses working cells in this inherited group of eye diseases. Rod cells, which help with night vision, are often affected before the cone cells used for daylight vision. This means trouble seeing in darkness may appear before daytime vision changes. Progressive retinal atrophy (PRA) usually develops slowly and is not painful itself, although vision can eventually be lost.

Signs to watch for

Uncertainty when moving around in dim light.
Avoiding dark rooms or nighttime outings.
Bumping into doorways, especially somewhere unfamiliar.
Pausing before going down steps.
Eyes that look unusually shiny when light catches them.

Some forms begin in puppies, while degenerative forms usually begin in adulthood; timing varies.

When to get help Arrange a vet visit for gradual vision changes, such as repeated bumps in dim light.

Diagnosis and tests

A vet examines the retina, the light-sensing layer at the back of each eye. An eye specialist may use electroretinography, a test of the retina's electrical response to light, to help confirm PRA. DNA tests check particular changes in genes rather than every possible cause of PRA. For example, Shetland Sheepdogs can be screened for a change in the CNGA1 gene. Testing negative for known variants cannot exclude all forms of PRA.

Breeds with documented risk

90 breeds

By breed size

5 Toy
23 Small
40 Medium
20 Large
2 Giant

All 90 breeds, A to Z

Drever Source skk.se
Dutch Shepherd

Finnish Lapphund

Karelian Bear Dog

Malshi
Medium Australian Labradoodle Source petmd.com
Medium Goldendoodle Source petmd.com
Mini Bernedoodle Source petmd.com
Mini Goldendoodle Source petmd.com
Miniature American Shepherd
Miniature Australian Labradoodle Source petmd.com
Miniature Labradoodle Source petmd.com

Old English Sheepdog

Redbone Coonhound
Russian Toy Source skk.se

Schapendoes Source schapendoes.fi
Schipperke
Sheepadoodle Source petmd.com
Sheprador Source petmd.com
Shichon Source petmd.com
Shih-Poo Source petmd.com
Shorkie
Siberian Husky
Silky Terrier
Sloughi Source d-nb.info
Spanish Water Dog
Standard Australian Labradoodle Source petmd.com
Standard Bernedoodle Source petmd.com
Standard Goldendoodle Source petmd.com
Standard Labradoodle Source petmd.com

Vizsla

Wirehaired Pointing Griffon

Yorkiepoo Source petmd.com

Inheritance

This condition has more than one known form, and different breeds inherit it in different ways. The sources list the form found in each breed.

Autosomal recessive
American Cocker Spaniel, American Eskimo Dog, Australian Cattle Dog, Australian Shepherd, Australian Stumpy Tail Cattle Dog, Barbet, Chesapeake Bay Retriever, Chihuahua, Chinese Crested, Cockapoo, English Cocker Spaniel, Entlebucher Mountain Dog, Finnish Lapphund, Golden Retriever, Goldendoodle, Karelian Bear Dog, Kuvasz, Labradoodle, Labrador Retriever, Lapponian Herder, Norwegian Elkhound, Nova Scotia Duck Tolling Retriever, Poodle, Miniature Poodle, Toy Poodle, Portuguese Podengo, Portuguese Water Dog, Schipperke, Silky Terrier, Spanish Water Dog, Swedish Lapphund, Swedish White Elkhound, Yorkshire Terrier
A dog is affected only if it inherits two copies of the gene variant, one from each parent. A dog with one copy is a carrier: usually healthy, but able to pass the variant on. When two carriers are bred, on average one puppy in four is affected. A DNA test can tell clear, carrier and at-risk dogs apart.
As stated by OMIA
Autosomal dominant
Bull Mastiff, English Mastiff
One copy of the variant, from either parent, is enough to put a dog at risk. On average, an affected dog passes the variant to half of its puppies. Males and females are affected equally.
As stated by OMIA
X-linked
Samoyed, Siberian Husky, Weimaraner
The variant sits on the X chromosome. Males have one X and females have two, so the condition shows up differently in males and females. It is often more common in males. The sources do not say whether one copy is enough in females.
As stated by OMIA
X-linked recessive
English Cocker Spaniel
The variant sits on the X chromosome. Males have one X, so one copy is enough to affect them. Females have two, so they are usually healthy carriers. Most affected dogs are male, and a carrier mother passes the variant to about half of her sons.
As stated by OMIA
Autosomal recessive, incomplete penetrance
Miniature Schnauzer
This is inherited like a recessive trait, so two copies are needed. But not every dog with two copies develops the condition. Age, other genes and environment also play a part. A DNA result shows risk, not certainty.
As stated by OMIA
X-linked
Miniature Schnauzer
As stated by PMC: Murgiano 2019

We've gathered what published sources say about this condition, so you can talk it through with your vet. It isn't veterinary advice: you and your vet know your dog best.