Achromatopsia in the German shepherd and Labrador retriever dog breeds

The German shepherd and the Labrador retriever are two of the UK’s most popular large dog breeds, and ones that a significant number of dog lovers have owned or are very familiar with.

Both of these popular large breeds are intelligent, energetic and loyal, and have long histories within a range of working roles thanks to their adaptability and versatility, which also helped them to make their more modern transition to life as pets. There are also a large number of differences between the temperaments and core behaviours of these two dog breeds, but there is something else notable that they have in common too; elevated risk factors for a canine health condition called achromatopsia, which is also known as “canine day blindness.”

Achromatopsia is a congenital health condition that can only be passed from dog to dog by means of heredity, and which causes the dog to be unable to see in bright lighting conditions such as full sunlight. However, affected dogs are usually able to see normally in dimmer light conditions.

The presence of the condition within dogs and its effects on dogs is something that has only recently been discovered, and a DNA-based health testing protocol has subsequently been introduced to enable owners of German shepherds and Labrador retrievers to get their own dogs health tested to find out their status.

This enables breeders to make an informed decision about which two dogs to mate in order to produce a healthy litter.

In this article we will look at achromatopsia in the German shepherd and Labrador retriever dog breeds, examining how the condition affects dogs, how it is inherited, and how the health testing scheme for achromatopsia in dogs works. Read on to learn more.

What is achromatopsia?

Achromatopsia is also known as “canine day blindness,” and it is a hereditary eye disorder that can also be found in humans. Exactly how severely it affects any given dog with the condition can be highly variable, but it leads to the dog in question being effectively blind or having impaired vision when in full sunlight. Dogs with the condition are much more capable of seeing in dimmer lighting conditions, whilst in sunlight or bright artificial light, they effectively lose their ability to see to a greater or lesser extent.

In bright light, affected dogs may be unable to see at all, or their vision might be severely blurred.

What sort of dogs can be affected by achromatopsia?

Achromatopsia in dogs is a hereditary health condition, and so it is only found within certain dog breeds within which members of the breed carry or are affected by a genetic mutation that causes the condition’s development.

At present, achromatopsia is recognised as having elevated risk factors within the Labrador retriever and German shepherd dog breeds. However, the condition has only recently been properly recognised in dogs at all, and so it may potentially affect other breeds too to a lesser extent. Even within the Labrador retriever and German shepherd breeds themselves, the condition is not particularly common or prevalent.

How is the condition transmitted between dogs?

Achromatopsia in dogs cannot be caught or passed on like a contagious condition, and can only develop in dogs that have inherited a hereditary predisposition to it, which occurs if the combination of genes that they inherit from their parents contain the markers for the affected form of the condition.

Achromatopsia in dogs is passed from parents to their young by means of autosomal recessive heredity. A dog’s status for the condition is expressed as clear, carrier or affected respectively.

The combined statuses of both parent dogs together is what dictates the status of the puppies in their litter, and it is possible for a litter to be born containing individual pups each respectively having any one of these three statuses if the genetic mixture of their parentage allows for this.

The status of a litter can be determined by knowing the status of their parents as follows:

• Two clear dogs will have a clear litter.
• Two affected dogs will have an affected litter.
• Two carrier dogs will have a litter of 50% carriers, 25% affected, and 25% clear.
• A clear dog and an affected dog will have a litter of carriers.
• A clear dog and a carrier will have a litter of 50% clear and 50% carriers.
• An affected dog and a carrier will have a litter of 50% affected and 50% carriers.

Health testing for achromatopsia in dogs

A DNA health testing scheme has recently been introduced for dogs of the Labrador retriever and German shepherd breeds to allow owners of dogs of these breeds to find out for sur their own dogs’ status for the condition. This is particularly important for dog breeders, as it allows them to work out whether or not any pups they produce from a given mating match will inherit the condition.

To get your dog DNA tested for their status, ask your vet to take a DNA sample from the dog and then send it away to an approved laboratory for testing. If you are considering buying a puppy of the Labrador or German shepherd breeds, you may want to ask the breeder if there is any history or achromatopsia within the breed line, and if so, to ask about their health testing protocols and test results.