Progressive retinal atrophy - rcd 3

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Progressive retinal atrophy (PRA) rcd 3 is a well-recognized autosomal-recessive genetic disease characterised by degeneration of the photoreceptor cells in the retina of Cardigan Welsh Corgi dogs, eventually leading to complete blindness.

The disease in this breed is caused by a frame-shift mutation in the PDE6A gene (as opposed to the 6B gene in Sloughi dog PRA.

Most PRA cases in the Cardigan Welsh Corgis are clinically indistinguishable from other forms of PRA.

Rcd3 has an early onset compared to other forms of PRA. Signs of rcd3 can be seen in Cardigan Welsh Corgi pups as early as 6 weeks old and affected dogs are usually blind by 1 - 2 years of age.

A breed-specific PCR test is available for testing for this condition[1].

There is no known treatment for this condition and severely affected individual dogs often remain blind.


  1. Petersen-Jones SM & Zhu FX (2000) Development and use of a polymerase chain reaction-based diagnostic test for the causal mutation of progressive retinal atrophy in Cardigan Welsh Corgis. Am J Vet Res 61(7):844-846