Progressive retinal Atrophy (basenji type) is an adult-onset inherited eye disease affecting basenjis. Affected dogs initially have changes in reflectivity and appearance of a structure behind the Retina called the Tapetum that is typically observed on a veterinary eye exam at around 5 years of age. Progression of the disease leads to thinning of the retinal blood vessels by 6 or 7 years of age, signifying decreased blood flow to the retina. Initial symptoms of disease in affected dogs include vision loss in dim light (night blindness) and loss of peripheral vision. The disease follows a variable progression and severity depending on the individual, but in many cases progresses to complete vision loss. Some affected dogs maintain vision in daylight for many years, sometimes for the remainder of their life.