Disease overview

Progressive Retinal Atrophy (PRA) causes breakdown of the retina, which is a part of the eye essential for vision. This is a progressive, non-painful disease that affects both types of photoreceptors: rods and cones. Rods are essential for night vision and movement, while cones are used for day vision and color.

Gene name

MERTK

Inheritance

Autosomal recessive

Signs and symptoms

PRA is a slowly progressive disease that causes vision loss in both eyes. This provides more opportunities for helping an affected dog adapt to its changing visual environment. This disease has a late onset of around 2-5 years of age. Signs typically start with night blindness, which progresses to daytime vision loss.

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 have or will lead to vision loss. Genetic testing is necessary to determine if there is an underlying genetic cause, which can assist veterinarians with diagnosis and help breeders identify affected and carrier dogs.

Breeds at higher risk

Citations

Everson R, Pettitt L, Forman OP, Dower-Tylee O, McLaughlin B, Ahonen S, Kaukonen M, Komáromy AM, Lohi H, Mellersh CS, Sansom J, Ricketts SL. An intronic LINE-1 insertion in MERTK is strongly associated with retinopathy in Swedish Vallhund dogs. PLoS One. 2017 Aug 16;12(8):e0183021. doi: 10.1371/journal.pone.0183021. PMID: 28813472; PMCID: PMC5558984.

Disclaimer

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