Disease overview

Progressive Retinal Atrophy (PRA) causes breakdown of the retina, which is a part of the eye essential for vision. This is a late-onset form of the disease that is progressive and non-painful. It affects both types of photoreceptors: rods and cones. Rod cells are responsible for vision in low light conditions and for detecting and following movement, while cone cells detect color and adjust brightness, but do not work as well in low light.

Gene name

SAG

Inheritance

Autosomal recessive

Signs and symptoms

PRA is generally a progressive disease where loss of vision occurs over time (allowing a dog to adapt more easily). Signs of change in the tapetum, the reflective surface of the eye, may begin as early as 5 years of age. These changes first cause night blindness, progressing to vision loss during the day and then complete blindness for most dogs.

How is it diagnosed

Thorough examination of the eyes and clinical signs. A veterinary ophthalmologic exam can determine if there are changes in the eye that could lead to vision loss. Genetic testing assists veterinarians with diagnosis and helps breeders identify affected and carrier dogs.

Breeds at higher risk

Citations

Goldstein O, Jordan JA, Aguirre GD, Acland GM. A non-stop S-antigen gene mutation is associated with late onset hereditary retinal degeneration in dogs. Mol Vis. 2013 Aug 27;19:1871-84. PMID: 24019744; PMCID: PMC3762564.

Goldstein O, Zangerl B, Pearce-Kelling S, Sidjanin DJ, Kijas JW, Felix J, Acland GM, Aguirre GD. Linkage disequilibrium mapping in domestic dog breeds narrows the progressive rod-cone degeneration interval and identifies ancestral disease-transmitting chromosome. Genomics. 2006 Nov;88(5):541-50. doi: 10.1016/j.ygeno.2006.05.013. Epub 2006 Jul 20. PMID: 16859891; PMCID: PMC4006154.

Disclaimer

Disease diagnosis and treatment should always be performed by a veterinarian. The following information is for educational purposes only.