Research inspired by a mountain rescue dog named Shola, whose work ended due to her failing eyesight, has led scientists to develop a genetic test that could eradicate progressive retinal atrophy (PRA) in dogs. PRA is an inherited eye disease causing deterioration of light-sensitive cells at the back of the eye, ultimately resulting in blindness.
This condition affects over 100 dog breeds and is caused by various genetic variants, with no current treatment available. Symptoms often do not appear until the dog is several years old, by which time they may have already passed the gene to their offspring.
Katherine Stanbury from the University of Cambridge, the first author of the study, noted that Shola began experiencing vision problems at the age of four. Further examination by a veterinary ophthalmologist confirmed PRA, and it was discovered that Shola’s brother also had the condition.
This revelation spurred Stanbury and her colleagues to investigate the genetic basis of PRA in English shepherds, leading to the development of a £48 DNA test to identify the presence of the PRA-causing variant.
Genetic Test Developed to Combat Progressive Retinal Atrophy in Dogs Inspired by Mountain Rescue DogThe team’s research involved whole genome sequencing of Shola and her brother, which revealed they did not carry any previously known PRA-associated genetic variants.
This indicated the presence of a different variant responsible for the condition in English shepherds. By analyzing the genetic data of additional English shepherds, both affected and unaffected by PRA, the researchers successfully identified the new variant.
The newly developed DNA test allows dog owners to determine if their English shepherds carry one or two copies of the PRA-causing variant. This knowledge can help breeders make informed decisions to avoid producing puppies with PRA, with the potential to eventually eliminate the condition from the breed.
Stanbury emphasized the importance of maintaining genetic variation within the breed, which is relatively rare, especially in the UK.
Shola’s case has already had a positive impact, as her offspring have been tested and confirmed not to carry the PRA variant. This means that her daughters can continue their mountain rescue work without the risk of developing blindness, and her son can fulfill his role as a therapy dog.
The research not only aims to protect English shepherds but also holds promise for identifying and monitoring PRA variants in other breeds, contributing to broader efforts to combat inherited eye diseases in dogs.