Progressive Retinal Atrophy (PRA-RHO) in dogs explained

Progressive Retinal Atrophy (PRA-RHO) in dogs is a hereditary eye disorder causing gradual degeneration of retinal cells, leading to slow loss of vision and eventual blindness. It specifically arises from a mutation in the dog’s RHO gene, inherited dominantly, meaning only one parent carrying the mutation can pass the condition to pups.

This article offers a compassionate, clear understanding of PRA-RHO, examining its causes, breeds most at risk, clinical signs, diagnosis, impacts on dogs’ wellbeing, and responsible breeding practices to prevent spread.

Understanding Progressive Retinal Atrophy RHO

PRA-RHO targets photoreceptor rod cells that enable dogs to see in dim light. Dogs are born with normal vision but develop night blindness early, with difficulty seeing edges and in low-light conditions. Over months or years, vision deteriorates to full blindness, affecting daytime sight as well. Although irreversible, the condition is painless, allowing owners to prepare and support their dogs during vision loss.

What Causes PRA-RHO in Dogs?

The underlying cause is a genetic mutation in the bullmastiff and mastiff breeds' gene pool. Because the mutation is autosomal dominant, even one affected parent can pass the gene to puppies. If both parents carry the mutation, progression often occurs faster. Importantly, PRA-RHO is not contagious and cannot develop spontaneously.

Breeds Most at Risk

Pedigree bullmastiffs and mastiffs carry a higher risk of PRA-RHO due to the gene mutation frequency in their lines. Cross-breeds with one bullmastiff or mastiff parent are also susceptible. Visible symptoms typically start to appear between six months and four years but can sometimes develop later.

How Is PRA-RHO Diagnosed?

Diagnosis involves veterinary ophthalmological examinations to detect retinal changes, often confirmed with an electroretinogram (ERG) which measures retinal function. Genetic testing available via simple DNA samples can determine if a dog carries the PRA-RHO mutation long before symptoms arise, providing crucial information for breeders and owners alike.

Living with PRA-RHO

While it is heartbreaking to learn a beloved dog may lose sight, the slow onset of PRA-RHO allows owners time to adjust the home environment. Dogs rely increasingly on other senses such as smell and hearing, and consistent surroundings help blind dogs navigate safely. Supportive care significantly enhances their quality of life.

Prevention through Responsible Breeding

Because there is no cure for PRA-RHO, prevention is vital. Reputable breeders use DNA testing to identify carriers of the mutation and avoid breeding from affected dogs. Even breeding an affected dog to a test-clear partner will still pass the gene on, so affected dogs should never be bred. Prospective buyers should seek breeders who openly share PRA-RHO testing results to ensure healthy pups.

Identifying PRA-RHO carriers early informs breeders to prevent passing the condition on, helping maintain the health of future generations and reducing the incidence of blindness in these breeds.

Frequently Asked: Can PRA-RHO be cured?

Quick Answer: PRA-RHO is a progressive genetic disease with no cure, but early diagnosis and supportive care can ease management.

Although PRA-RHO leads to blindness, regular veterinary eye checks and environmental adaptations can provide a good quality of life for affected dogs. Genetic screening remains the best strategy to prevent the condition through careful breeding decisions.

Summary and Next Steps

Progressive Retinal Atrophy PRA-RHO is a responsible owner's challenge but also an opportunity to make informed breeding choices to protect future dogs. Understanding its genetic basis, recognising early signs, and adopting proper care can help affected dogs live well sighted or blind. Choosing reputable breeders committed to DNA testing is essential for anyone considering bullmastiff puppies or mastiff puppies to reduce PRA-RHO risks.