Early Onset Progressive Retinal Atrophy (EO-PRA) is an inherited eye disease that affects the Spanish Water Dog breed. This disease is caused by degeneration of retinal photoreceptor cells which are used for vision in both dim and bright light. Symptoms of the disease present early with vision issues becoming apparent at approximately 1 year of age. The disease gradually progresses with significant vision loss by approximately 4-5 years of age. Dogs will initially experience reduced vision in dim light (also known as night blindness) and can also include issues with peripheral vision. As the disease progresses, dogs will eventually start to experience reduced vision in brighter light. Physical signs of the disease can be observed during a veterinary eye exam.

• Spanish Water Dog

A (CLEAR/NORMAL): These dogs have two copies of the normal gene and will neither develop early onset progressive retinal atrophy nor pass this mutation to their offspring.

B (CARRIER/NOT AFFECTED): These dogs have one copy of the normal gene and one copy of the mutation associated with this disease. They will not develop early onset progressive retinal atrophy but will, if bred, pass the mutation to 50% of its offspring, on average.

C (AT RISK/AFFECTED): These dogs have two copies of the mutation associated with this disease and are susceptible to developing early onset progressive retinal atrophy.