Glaucoma and goniodysgenesis DNA health testing for the Border collie dog breed

Border collies are the world’s smartest dogs based on their intelligence, capacity to learn and working ability, and this is why they are still widely used for a large number of different working roles today, most notably as herding dogs to work with sheep.

Border collies are also really popular as pets, and whilst their need for exercise is very onerous and can be a challenge to meet within a domestic home environment, there is an awful lot to recommend them as companions for active owners who love to spend time outside.

The border collie breed as a whole is one that is robust and hardy, as you might expect from a working breed, but there are also a few hereditary health conditions that can be found within the breed too that can be passed on from dog to dog by means of inheritance.

Most such conditions are thankfully rare even within dogs of the breed, but all prospective Border collie owners are strongly advised to find out about the hereditary health issues that can affect their dogs, and take steps to choose a healthy puppy.

Responsible Border collie breeders undertake DNA health screening on their breeding stock to identify the markers of hereditary health conditions that can be tested for and that might be present within the gene pool, and potential puppy buyers should aim to choose a puppy from a breeder that has undertaken all of the necessary Border collie health tests.

One DNA test that can be performed on Border collie breeding stock is tasked with identifying the markers of a health condition that affects the eyes, called glaucoma and goniodysgenesis (GGD).

In this article we will provide a short introduction to glaucoma and goniodysgenesis in the Border collie breed, and explain how this condition is inherited and what Border collie owners need to do to get their own dogs tested.

Read on to learn more about glaucoma and goniodysgenesis DNA health tests for the Border collie.

What is glaucoma and goniodysgenesis?

Goniodysgenesis is a condition that affects the eyes, and which occurs as a result of the abnormal development of the anterior chamber of the eye, which can cause both the development of glaucoma and potentially, blindness.

Goniodysgenesis causes problems with the natural drainage of fluid from the eye, leading to a build-up of this fluid that in turn, places pressure on the eye, increasing the intra-ocular pressure on the inside of the eye too. This can cause permanent damage to the eye’s optic nerve, as well as vision loss.

The symptoms of glaucoma and goniodysgenesis in the Border collie include runny or watery eyes, pain in and behind the eyes, hypersensitivity to light, eye ticks and spasms, and abnormally dilated pupils.

Glaucoma and goniodysgenesis in the Border collie occurs because of a gene mutation, which has only recently been discovered by research scientists and vets in the UK. Now that the exact gene mutation responsible for Border collie glaucoma and goniodysgenesis have been discovered, a DNA testing scheme has been introduced for the breed to identify the markers of the condition in dogs.

How do Border collies inherit glaucoma and goniodysgenesis?

Whilst there are lots of different types of (and causes for) glaucoma in dogs, glaucoma and goniodysgenesis (GGD) in the Border collie is hereditary, and occurs when a dog inherits a combination of mutated genes for the condition from their parents.

Glaucoma and goniodysgenesis in the Border collie is passed on by means of autosomal recessive heredity, and requires the dog in question to inherit the gene mutation from both sides of their parentage. If just one parent dog carries the mutation but the other does not, their offspring will not be affected either, although they may become carriers of it and so, be able to pass it on in their turn.

Glaucoma and goniodysgenesis in the Border collie is passed on by heredity as follows:

• Two affected parent dogs will have an affected litter.
• Two clear parent dogs will have a clear litter.
• Two carrier-status parents will have a litter with mixed results; each pup will have a 50% chance of also becoming carriers, a 25% chance of being clear, and a 25% chance of being affected.
• A clear dog and a carrier will have a litter of 50% clear pups and 50% carriers.
• A clear dog and an affected dog will have a litter of carriers.
• A carrier and an affected dog will have a litter of 50% carriers and 50% affected pups.

DNA health testing for glaucoma and goniodysgenesis in the Border collie breed

In order to find out the status that a litter produced from any given mating match will inherit, you need to know the status of both parent dogs, which means both dogs need to be DNA tested prior to breeding.

This allows breeders to predict whether or not the pups in any litter will inherit the condition themselves, and make a conscious decision about the right mating match.

To get a Border collie tested for glaucoma and goniodysgenesis (GGD), you just need to let your vet know and book an appointment for them to take a DNA sample from the dog in question. They will then send the sample off to one of the UK’s approved laboratories that can test for the relevant gene mutation, and the laboratory will in turn return a result of either clear, carrier or affected for each tested dog.