Preventing Progressive Retinal Atrophy in Dogs

Dog Breeds

Currently, there are no treatment options available for progressive retinal atrophy in dogs. There are also no medications or therapies which can slow the progressive loss of vision which is caused by this disease. However, there are some preventative measures that are currently in place which will help to eventually eliminate this disease from the gene pool in affected dog breeds. Pet owners also have options they can use to ensure that their adopted dog does not have, or carries a gene for, this disease.

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Introduction

Progressive retinal atrophy (PRA, also called retinal degeneration) refers to a group of inherited, noninflammatory, and non-painful diseases of the retina that lead to blindness. PRA must be distinguished from sudden acquired retinal degeneration (SARD), which typically affects older dogs, especially females.

Common clinical signs of PRA include night blindness followed by progressive loss of vision in bright light. Cataracts can also occur. PRA always progresses to complete blindness. However, the progression is often slow enough for the dog to adapt well to its loss of vision.

Currently, there is no way to prevent progressive retinal atrophy in dogs, nor are there any medications or other therapies proven to slow or reverse the progressive loss of vision which it causes. However, there are some preventative measures that breeders can adopt to help eliminate this disease from the gene pool in affected breeds. Pet owners can also take steps to ensure that the dog they purchase or adopt does not have, and does not carry the gene for, progressive retinal atrophy.

Preventing PRA in Dogs

Most forms of progressive retinal atrophy are passed from parent to offspring in an inheritance pattern known as “autosomal recessive.” This is especially true in Collies, Irish setters, Miniature poodles, Cocker spaniels, Briards, and Labrador retrievers. In these breeds, if a dog has inherited the gene responsible for PRA from only one parent, it will not develop the disease but will be a carrier of the trait – meaning that if bred, it can pass that gene on to its offspring. However, if a dog inherits the “PRA gene” from both parents, it will eventually develop clinical PRA.

In several breeds, particularly Samoyeds and Siberian huskies, PRA is passed on in a dominant inheritance pattern, meaning that even if a dog gets only one copy of the gene, it will develop the disease. In many breeds, the mode of inheritance is not known.

The key to preventing PRA is held by responsible breeders of affected breeds. These animals should be genetically screened for PRA by a board-certified veterinary ophthalmologist and have the results of that screening registered through the Canine Eye Registration Foundation (CERF). Dogs found to be carrying the gene for PRA – whether or not they actually have the disorder – should not be bred. Offspring of affected dogs likewise should not be bred. Responsible breeding practices are the only way to remove animals with PRA from the breeding population.

Genetic testing of blood samples is available to identify whether a particular dog carries the gene for PRA. The best way to ensure that your new dog does not carry the PRA gene, and therefore will not develop the disorder, is to have both of its parents tested, if possible. This is especially important if the dog you are considering belongs to one of the commonly affected breeds, and even more so if you are thinking about breeding the animal in the future. Any dog found to be carrying a PRA gene should be spayed or neutered.

Once a dog is diagnosed with PRA, blindness is inevitable. However, most dogs adjust quite well to vision loss, especially when it comes on gradually as it does with PRA. There are a number of simple steps owners can take to help their dog deal with loss of vision. Of course, the dog should be watched or kept on a leash when outside and not in a fenced area. Dogs are quite good at memorizing where objects are in their environment, so owners of vision-impaired dogs should avoid rearranging their furniture. Spraying perfume on furniture can help a blind dog identify where that object is. Toys that make noise are popular. Owners of dogs with PRA should keep items picked up off the floor and should take their dog for lots of on-leash walks, so that it can acclimate to the environment outside of its home comfort zone while benefiting from physical activity and mental stimulation.

Symptoms and Types

Overview and Facts