7 Sept 2023
Collaborative project between Dick White Referrals and University of Cambridge has led to DNA test for genetic variant that causes inherited optic disease in old English sheepdogs.
Paul Imrie
Job Title
Image © raywoo / Adobe Stock
Vet clinicians and geneticists in Cambridgeshire have teamed up to develop a DNA test after identifying the genetic variant behind an inherited eye disease syndrome in old English sheepdogs.
The breakthrough was spearheaded by specialist vets at Linnaeus-owned Dick White Referrals (DWR) Veterinary Specialists and a team at The Kennel Club Genetics Centre based at the University of Cambridge.
The DNA test means breeders can screen for the gene that can cause blinding eye problems in the breed.
Research started when James Oliver, head of ophthalmology at DWR, examined an old English sheepdog used for breeding and found it had cataracts.
It was referred for more detailed examination and diagnosed with both cataracts and multi-ocular defects, so it wasn’t suitable for breeding but still required medical attention.
He said: “The dog had multiple eye defects. We do see this occasionally in various breeds, including old English sheepdogs. Not a lot is known about it and we didn’t know how it is inherited or what potentially the genetic base of the disease might be.”
Dr Oliver added: “This kickstarted the project and, as vets, we collected DNA samples from several dogs with similar problems and the geneticists discovered the gene involved, and the specific mutation within that gene that seems to be causing the blinding eye problem within this breed.
“The old English sheepdog is quite a rare breed and it only takes a very small number of breeding animals who carry a genetic defect for that mutation to become more widespread.
“Now we’ve discovered the gene causing the issue, we’ve established a DNA test so that old English sheepdog breeders can use this test to work out if their dogs carry the mutation and, therefore, make sensible breeding decisions to ensure affected puppies are not produced going forward by inappropriate mating.”
Senior research associate Cathryn Mellersh and research associate Katherine Stanbury, both from The Kennel Club Genetics Centre, were involved in the project, which had support from The Kennel Club Charitable Trust and a grant from Dogs Trust.
Dr Mellersh said: “Projects such as these need four parts to complete the puzzle. It requires the clinicians, the geneticists, owner cooperation and funding.
“Working with DWR has been vital to the success of this research. When you know the underlying defect you can develop a DNA test so that breeders can use it to prevent the disease happening in the future.
“It is very exciting that we have found the genetic cause and breeders can test their dogs for the mutation. It’s also a great example of clinicians and researchers working together to benefit animal welfare.”
Canine Genetic Testing, based at the University of Cambridge, is the only service currently offering the test. Full details are available online.
