PROGRESSIVE RETINAL ATROPHY (PRA)
This condition was first identified in Abyssinian cats more than thirty years ago. Then in 2009 a study of many different breeds showed the gene mutation responsible was far more widespread than originally believed.
A cat with one copy of the faulty gene (heterozygous or carrier) is not affected but a cat with two copies (homozygous or affected) will go blind gradually over time. Some cats will be blind by the time they are three and some will be spared until relatively old age. The oldest we know of was thirteen but generally the age at which loss of sight is complete will be between these two extremes.
The bad news
testing so far carried out, it seems this gene is worryingly common in
Siamese and Oriental breeds in this country.
If all breeders test their breeding cats and always mate affected and carrier cats to negative mates, no more cats will be born destined for the dark.
you belong to
a breed club that has a 20% discount on DNA testing at Langford ( see
page on this site ) the cost of ensuring you are breeding responsibly
Facts worth noting
in general practice are unable to
diagnose the condition since the Pupillary Light Reflex (PLR) remains
sight is gone.
(Although the first two pictures look normal these two cats are blind)
There have been four stages identified in the progression of the disease. The older the cat when it reaches stage one, the slower the destruction of the retinas.
The change in the appearance of the eye is far less marked in Siamese even in poor light. It will be more noticeable in dilute Orientals’ eyes than in the dense colours.
For further information about the
condition, help in managing breeding or just to discuss ways of coping
with the problem,
please see our WELFARE
page for details
of how to contact our Welfare Officer