Welcome to the Corgi Corner! This series is posted on the first Saturday of every month! These posts help spread education and awareness on topics like general dog care, corgi specific things, medical care, health facts, etc. This month’s Corgi Corner post will be all about progressive retinal atrophy! Progressive retinal atrophy (PRA) is an inherited eye disease that affects the cells in the retina that leads to blindness in dogs. It’s a non-painful condition that tends to slowly progress over time. There are several different genetic variants that can cause PRA, but all of them lead to the same outcome: cell degeneration in the retina, which is located in the back of the eye. The retina contains cells, called photoreceptors, that collect information about light and send signals to the brain. There are two types of photoreceptor cells: rods, for night vision and movement, and cones, for day vision and color. Dogs with PRA are typically born with normal rods and cones, but the cells start to break down over time. Rods will die before cones, causing night vision to be affected first. This slowly progresses into blindness, but the progression and age at which the majority of vision is lost will vary. Generally, it happens between the ages of 3 to 9 years and there can be complete vision loss over a period of 1 to 2 years. PRA is diagnosed with an eye exam focusing on the retina. Veterinarians use a focused light to examine the pupils. In affected dogs, the pupils will appear more dilated and slower to contract. The vet may also use a lens to visualize the retina at the back of the eye to look for changes in the optic nerve or blood vessels. There may be a referral to a veterinary ophthalmologist for further testing and a definitive diagnosis. Genetic testing for inherited PRA can also be done. Currently, there is no cure available. There is also no definitive treatment for PRA. Supplements, including antioxidants, have been proposed for management of the disease, but haven’t been scientifically proven effective. PRA management mainly focuses on helping dogs avoid injury and feel safe in their environment as their vision declines. Overall dogs adapt well to their vision loss and can continue to have a good quality of life. There are several different known variants of PRA, all of which can be tested through DNA testing. The most common form of inherited PRA is called progressive rod-cone degeneration (PRCD). This condition is recessive, so two copies of this variant must be present to consider a dog at risk. One copy means they are only a carrier. Some breeds that can have this form include Pembroke Welsh Corgis, Cardigan Welsh Corgis, Australian Cattle Dogs, Poodles, Labrador Retrievers, Golden Retrievers, and Cocker Spaniels. The specific variant that’s seen in Pembroke Welsh Corgis and Cardigan Welsh Corgis is PRA-rcd3.  There are also a few known variants that are called dominant variants (which require only one copy) or X-linked variants (requiring one copy for males and two copies for females). Dominant variants can be seen in Old English Mastiffs and Bullmastiffs, while X-linked variants can be seen in Siberian Huskies and Samoyeds. However, some forms of PRA do not have known generic variants, meaning a dog can still develop the disease even if they test negative for the known variants. PRA can be increasingly less common through genetic testing and reputable breeding practices. Reputable breeders will test their parent dogs prior to breeding to determine if they have a known inherited variant of PRA and what type and how many copies they have. They will also provide proof of this to any potential new puppy parents. Unfortunately, this can still be seen in Pembroke Welsh Corgis and Cardigan Welsh Corgis because of irresponsible breeding practices by backyard breeders and puppy mills.