Progressive Retinal Atrophy (PRA) is an inherited degenerative eye disease affecting certain cat breeds, leading to gradual vision loss and eventual blindness. While relatively rare in cats, it predominantly affects breeds such as the Siamese (including related breeds like Balinese, Orientals, and Colourpoints), as well as Abyssinians, Somalis, and Ocicats. This condition causes the photoreceptor cells in the retina, crucial for converting light into nerve signals, to deteriorate over time. Typically, rod cells responsible for low-light vision fail first, causing night vision difficulties as an early symptom. PRA is a progressive condition with no current cure, highlighting the importance of early diagnosis and responsible breeding practices.
The earliest sign of PRA in cats is usually night blindness, where your pet may become hesitant in dark areas or bump into objects at night. Cats with blue eyes, such as Siamese, may develop a milky greenish hue in their eyes as the disease progresses. A veterinary ophthalmic examination using an ophthalmoscope can reveal characteristic changes in the retina, including degeneration of photoreceptors and increased eye reflectivity. Because the disease progresses gradually, some cats adapt well to vision loss and can continue to live active, happy lives with some environmental adjustments.
PRA is inherited, with a significant percentage of Siamese and related breeds carrying the gene responsible. Breeding two carrier cats risks producing affected kittens, often with normal vision at birth that deteriorates over a few years. Responsible breeders test both males and females through straightforward genetic mouth swab tests, such as those provided by the University of Bristol's Veterinary School at Langford. Identifying carriers prevents passing the disease to future generations and is a vital step toward controlling PRA in the feline population.
While PRA is irreversible, affected cats generally maintain good quality of life. To ensure safety, it is advisable to keep blind cats indoors or in securely enclosed gardens, away from busy roads. Cats adapt surprisingly well, using their other senses and memory of their environment to find food, litter trays, and favourite resting spots. Avoid rearranging furniture frequently to prevent accidents. Providing a stable, loving environment helps your cat thrive despite vision loss.
The key to reducing PRA's impact is awareness and testing before breeding. If you are considering purchasing a Siamese or related breed, request proof of genetic testing from breeders to ensure the risk of PRA is minimised. Such conscientious choices support the health and welfare of future generations. By promoting responsible ownership and breeding, the feline community can work towards stamping out this hereditary disease.
Progressive Retinal Atrophy presents challenges but also opportunities for responsible care and breeding practices. Early symptom recognition, veterinary diagnosis, and genetic testing are essential tools. If your cat is diagnosed with PRA, adapting their environment and ensuring safety will promote a happy life. As breeders and owners work together responsibly, the incidence of PRA can decline over time, preserving the joy of sight in beloved cat breeds.