3 Jan 2020
Vets and scientists at the AHT have developed a DNA test to help eradicate the severe form of retinal dysplasia in which the retina never developes properly.
David Woodmansey
Job Title
An inherited retinal disease that presents as retinal detachment and blindness in puppies has been identified in cocker spaniels.
Believed to be the canine equivalent of Norrie disease in children, it is a severe form of retinal dysplasia in which the retina never develops properly.
Vets and scientists at the AHT have developed a DNA test to help eradicate this severe form of the disease within the breed before it takes hold.
Vets4Pets-sponsored research assistant Hattie Wright, who is part of the AHT’s canine genetics research team, led the project.
She said: “Usually, dogs affected by retinal dysplasia appear normal or demonstrate subtle symptoms, such as hesitancy in everyday life or clumsiness. It is very often diagnosed as an incidental finding, but in some cases it can be progressive and result in vision loss.
“The conventional form of retinal dysplasia, for which there is no treatment, is well documented in nine breeds, but was previously unrecognised within cocker spaniels.”
The condition was identified when an affected dog was referred to the ophthalmology service in the AHT’s Small Animal Referral Centre.
It was revealed another male puppy from the same litter was affected, alongside two maternal uncles – which led researchers to suspect the inherited eye disease was caused by a mutation on the X chromosome, meaning males were far more likely to be affected than females.
As part of her work on the project, Miss Wright investigated and identified the causal mutation. Results showed the mutation was rare in the breed, but thanks to this research it can be prevented from becoming more common.
Miss Wright said: “As this condition in cocker spaniels is quite rare, we’re not expecting to find many affected dogs through DNA testing, but it is crucial to identify any carrier females to prevent more puppies being born with this blinding condition and to stop it becoming more widespread in future.”
