Severe goniodysgenesis is an inherited condition in which a dog’s eyes don’t develop properly. In some dogs, it can lead to glaucoma, which causes sudden blindness at a young age.

Scientists have discovered a change in the genetic code of border collies that has the potential to prevent sudden and catastrophic blindness in the breed.

The findings, by researchers from the University of Edinburgh’s Roslin Institute at the Royal (Dick) School of Veterinary Studies, have led to a new genetic test for a severe version of the condition – called goniodysgenesis – to help breeders worldwide avoid producing affected pups.

Severe goniodysgenesis is an inherited condition in which a dog’s eyes don’t develop properly. In some dogs, it can lead to glaucoma, which causes sudden blindness at a young age.

Show dogs affected

Carys Pugh, a research fellow at The University of Edinburgh who has worked on the study for five years, explained sudden blindness in border collies had emerged in Australia during the late 1990s and spread worldwide.

All the affected animals were show dogs, with many related to each other. When it appeared in the UK – in dogs related to the Australian dogs – breeders suspected it may have a genetic cause.

No working border collies are understood to have been found with severe goniodysgenesis, only show dogs.

Dr Pugh and her colleagues collected DNA from dog saliva samples and compared those that had healthy eyes to those with symptoms of severe goniodysgenesis.

They identified a mutation in the gene called Olfactomedin Like 3 (OLFML3) – which may be involved in the early stages of development of the eyeball. All of the dogs that went blind had two copies of the mutated gene.

The work, “Arginine to glutamine variant in Olfactomedin Like 3 (OLFML3) is a candidate for severe goniodysgenesis and glaucoma in the border collie dog breed”, has been published in the journal G3: Genes, Genomes, Genetics.