Your pet’s genes greatly influence their appearance, behavior, and health. Humans have learned to manipulate pet genetics to produce breeds that fit our needs—from hunting rodents, to herding sheep, to looking adorable sitting on their owner’s lap. Unfortunately, genetics are highly complex, and breeding pets for specific traits and appearances can unexpectedly create gene combinations and the right conditions for disease development. We call such diseases genetic, breed-related, or inherited disorders. Veterinary Vision Center shares more information about common genetic eye diseases and how they can affect your pet.

What do veterinarians know about genetic eye diseases in pets?

The American College of Veterinary Ophthalmology (ACVO) and the Orthopedic Foundation for Animals (OFA) have published guidelines regarding many inherited animal diseases, including eye diseases. Most genetic diseases are not well understood, because lengthy, expensive scientific studies are required to identify the responsible genes, learn how they are passed on, and what affects their expression. While a few genes have been well-defined and testing is easy, most others are generally accepted or presumed to have a genetic basis when they meet the OFA’s criteria. 

Diseases with the greatest impact on pet eye health and vision are the most studied, so veterinary medicine professionals can understand their treatment and prevention. Other diseases that are observed more frequently in certain breeds and related individuals from certain breeds, and that have a predictable appearance and disease course in those breeds, are presumed genetically inherited.

What are the most common genetic eye diseases in pets?

Many pet eye diseases have some genetic component, and each breed is more prone to developing particular conditions. The complete list is extensive, but the diseases we see most commonly include:

  • Eyelid disorders — Eyelids that roll in or out, or grow abnormal hairs, are more likely in wrinkly-faced and bug-eyed breeds, such as the bulldog, pug, shih tzu, shar-pei, and Saint Bernard.
  • Third eyelid disorders — Prolapsed third eyelid glands are common in small, flat-faced breeds, and bent third-eyelid cartilage occurs in giant breeds. 
  • Glaucoma — Glaucoma, which causes painfully elevated eye pressure and blindness, affects many breeds, including the Siberian husky, cocker spaniel, shih tzu, poodle, shiba inu, Basset hound, and beagle.
  • Cataracts — Cataracts, especially those that occur early in life, likely have an underlying genetic component.
  • Merle gene disorders — Dogs with the merle gene, which creates beautiful coat patterns, can be born with different degrees of eye and ear abnormalities, including complete blindness or deafness, or both. Breeds include the dachshund, Australian shepherd, Catahoula leopard dog, bully breeds, and many more.
  • Retinal disease — Shih tzus are prone to spontaneous retinal detachment, and many breeds, including poodles and retrievers, develop progressive retinal atrophy. Retinal disease often leads to complete blindness.
  • Collie eye anomaly — Many collies are born with small eyes and abnormalities in eye structure that lead to reduced vision or blindness.
  • Corneal dystrophy — Young Cavalier King Charles spaniels may develop harmless white areas on their corneas, but a different variant that affects older Boston terriers can cause complete blindness.
  • Pannus — Pannus causes inflammation and scarring on the corneas in German shepherds and greyhounds.
  • Pigmentary uveitis — This disease causes cysts, inflammation, and subsequent glaucoma and blindness in golden retrievers.

How do I know if my pet has a genetic eye disease?

Different eye diseases occur at different times in a pet’s life. As with any disease in any body part, you cannot predict your pet’s future health. If your purebred pet is at high risk for genetic eye diseases, you should schedule annual examinations with our team, so we can detect changes in their early stages. 

Specific genetic tests are available to detect disease-causing genes in certain breeds. These tests can identify problem genes, but cannot predict whether your pet will develop the disease later on, or disease severity. Some tests designed to identify breeds in mixed-breed dogs of unknown parentage, like this one by Embark, can also screen pets for some genetic diseases, but they cannot be sure that your pet will be affected.

Why haven’t breeders eliminated genetic eye diseases in pets?

We still don’t know enough about genes and inheritance modes to eliminate every genetic disease. Knowledgeable breeders work hard to improve their breed through eye exams and genetic testing of parent pets, but eliminating diseases is unlikely. Do your research before choosing a breed and breeder, or adopt a shelter mixed-breed pet if you have concerns about genetic eye diseases.

All pets, including purebred, mixed-breed, and exotic pets, can benefit from routine eye health screenings by our Veterinary Vision Center team. We can also perform certification exams and recommend appropriate genetic tests to ensure eye health for breeding animals. Contact us to schedule a routine or pre-breeding pet eye examination, or if you have questions about genetic eye diseases in pets.