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New test identifies cause of blindness in giant schnauzers


The DNA test for PRA in giant schnauzer, costing £48, is now available from the AHT DNA Testing Service.

An inherited retinal disease that leads to blindness has been identified in giant schnauzers.

Progressive retinal atrophy (PRA) condition, which has no treatment, is well documented in more than 100 breeds of dogs, but was previously unrecognised within this breed.

Eradicate

Vets and scientists at the AHT have now developed a DNA test to eradicate the disease within the breed before it is able to take hold.

The Kennel Club Genetics Centre at the AHT received DNA samples from a litter of four-year-old giant schnauzers, with two of the seven littermates having been previously diagnosed with PRA.

Causal mutation

Follow-up examinations of one additional dog in the litter and both parents revealed three of the seven littermates had PRA and both parents were clear of the disease.

This confirmed the presence of an autosomal recessive PRA, where an affected dog has to carry two copies of the PRA-causing variant to develop the disease.

A genetic study was launched to identify the causal mutation, and results revealed mutation was rare within the breed, with approximately one in 35 dogs carrying it.

Rare condition

Rebekkah Hitti, research assistant and PhD student within the Kennel Club Genetics Centre at the AHT, said: “As this condition in the giant schnauzer is quite rare, we’re not expecting to find many affected dogs through DNA testing, but it is crucial to identify any carriers to prevent more puppies being born with this blinding condition, and to stop it becoming more widespread in future.

“We’ve had a good level of interest in this research so far from schnauzer breeders and we’re confident this breeding community is keen to get this mutation under control and, in time, eradicate it safely from the breed altogether.”