Dominant progressive retinal atrophy (D-PRA) in dogs

Progressive retinal atrophy is one of the leading causes of painless, progressive and irreversible blindness in dogs, which in its turn comes in several different variants depending on the action of the condition and how it is passed on from dog to dog.

Most forms of progressive retinal atrophy in dogs are autosomal recessive traits, which means that unless any given puppy inherits a copy of the gene mutation behind the condition from both parents, they won’t be affected by the condition themselves. However, there are also forms of progressive retinal atrophy that are inherited by means of autosomal dominant heredity, which means that a pup need only have one affected parent in order to develop the condition.

D-PRA or dominant progressive retinal atrophy is one such variant of the condition, and so far, this type of progressive retinal atrophy is only considered to be a particular threat to the bullmastiff and mastiff dog breeds. This means that owners of dogs of these breeds, particularly those that may be considering breeding from their dogs – as well as potential puppy buyers – should be aware of the condition and how it spreads across the breeds.

In this article we will look at D-PRA or dominant progressive retinal atrophy in dogs in more detail, including how the condition affects dogs, how it is spread from dog to dog, and how to ensure that you only breed or buy healthy dogs that are clear of the condition. Read on to learn more.

What is D-PRA or dominant progressive retinal atrophy in dogs?

Progressive retinal atrophy is a group of eye disorders that can arise in dogs as the result of inheriting a certain combination of gene mutations from one or both of their parents.

Dogs who inherit the active form of the condition are born with normal vision, but will progressively lose their sight as they age, until they ultimately become totally blind.

This loss of vision is painless, but can have an impact on the dog’s lifestyle and normal activities because full or partial sight loss is of course potentially restricting in many areas of the dog’s life.

The dominant form of PRA or D-PRA indicates that the gene mutation that causes the condition is a dominant one, or that only one copy of the mutated gene need be inherited to cause the condition in offspring of the affected parent dog.

Because D-PRA might not become apparent in dogs until they are several years old, affected dogs may already have been bred from and so, passed on the condition before they are identified as sufferers themselves.

What sort of dogs are at risk of the condition?

D-PRA has been identified within bloodlines of the bullmastiff and mastiff dog breeds, which means that all mastiff and bullmastiff owners, breeders and potential buyers should be aware of the condition.

Additionally, because the condition is dominant, a mastiff or bullmastiff crossed with any other breed might potentially produce an affected litter, unless the breeding stock are tested for their status prior to breeding, and any affected dogs removed from the breeding programme.

How D-PRA is passed from dog to dog

D-PRA is not a contagions condition, and the only way that a dog or puppy can develop the condition themselves is by inheriting the gene mutation that causes the condition to develop.

Dominant progressive retinal atrophy is passed from dogs to their young by means of autosomal dominant heredity, which means that potentially, just one parent dog being affected by or carrying this mutated gene can cause some or all of their offspring to inherit the condition themselves.

However, in order to prevent the spread of D-PRA throughout the bullmastiff and mastiff breeds, any person breeding or considering breeding from dogs of these two breeds are advised to have their dogs DNA tested first, in order to find out their status.

The DNA test for D-PRA requires a cheek swab or blood sample to be taken from your dog by their vet, and then sent off for laboratory analysis. This analysis then returns a result of the dog’s status, allowing their owner to make an informed decision about whether or not they should be bred from.

Breeding and buying healthy dogs

If you are consideringadopting or buying a bullmastiff or mastiff dog or puppy, you should always ask breeders before you view their litters if their parent stock are tested for the condition first. Ask to see the results of D-PRA testing, and only consider breeders who have their dogs tested and breed from only healthy dogs.

Breeders of bullmastiffs and mastiffs are urged to test all of their breeding stock – and if using a stud dog, ensure that the other dog is also tested, and have results available to view.

Testing and selective breeding helps to inhibit the spread of D-PRA throughout the affected breeds, improving the health of their breed lines and helping to ensure that future generations have healthy eyes.