Unlocking Canine Retina Health: Blindness, Detachments and Genetics in Dogs

Join Marty and Laura as they dive into the complex world of the canine retina, exploring common eye diseases, the dangers of retinal detachment and essential genetic health screenings.

Our hosts focus on the canine retina, an essential part of the back of the eye that acts like the “film” in a camera to interpret light, images and motion. Because the retina is a highly complex structure, diagnosing retinal issues often requires the specialized equipment and training of a veterinary ophthalmologist.

Key Topics Discussed:

• Retinal Detachment: This is a severe condition that usually results in blindness. In dogs, it can be triggered by trauma, tumors, immune-mediated diseases, uveitis, or high blood pressure linked to kidney failure or hyperthyroidism. While humans can often have their retinas reattached via laser, it is incredibly difficult and rare to successfully reattach a dog’s retina.
• Hidden Blindness in Pets: Dogs and cats are incredibly skilled at hiding their vision loss by memorizing their home’s layout. Owners may not realize their pet is going blind until they rearrange the furniture or move to a new house.
• SARD (Sudden Acquired Retinal Degeneration): A rare, irreversible condition of unknown cause where a dog suddenly goes blind.
• The Dangers of Merle-to-Merle Breeding: Breeding two dogs with the Merle gene (such as Aussies or Collies) can produce puppies with severe visual and hearing impairments. It is crucial to DNA test for “cryptic Merles” to avoid accidentally crossing two Merle dogs.
• The “Hybrid Vigor” Myth: Mixing two breeds, such as a Bernese Mountain Dog and a Poodle to make a Bernadoodle, does not magically cure or filter out bad genetic traits. Sometimes, this combination actually doubles up on genetic issues.
• Health Testing & Preventive Care: Responsible breeders and owners should utilize both DNA tests for conditions like Progressive Retinal Atrophy (PRA) and physical exams by a veterinary ophthalmologist. Breeders can visit the Canine Health Information Center (CHIC) website to discover which specific eye diseases to test for based on their dog’s breed.
• Medication Toxicities: Giving a dog a massive, accidental mega-dose of ivermectin—such as using farm store variants instead of proper heartworm preventatives—can lead to temporary blindness.