What is CEA?

What is PRA?

Eye examination

PRA means inherited progressive retina atrophy. The disease will at first cause limited vision, but in time the dog will get blind. The first symptom is reduced night vision, which will often show as insecurity on the late eveningwalk. The dog may stay closer to the owner than it used to or bark unjustified at wellknown objects. Normally a dog has six times better night vision than a human and is adapting well outdoors at night. In dim light indoors, the eyes on a dog with PRA may shine or glimmer with an abnormal and strong shimmer. When the dog starts showing problems with his vision even in daytime, the changes have gone far.

At an eye examination, typical changes can be discovered in the retina months or even years before the dog will get problem with seeing. You will then see a changed shimmer in the lighter parts of the retina, a moving of the colourgrains in the darker parts and a gradually thinning of the retinas normally copious bloodvessels.

PRA is debuting at various ages in various breeds. Clinically you talk about early and late forms. Early forms are developing faster into blindness than late. The inheritance of PRA in all breeds (except one) has been considered simple recessive autosomal. That means that a sick dogs both parents are at least carriers of the gene and that every puppy from a sick dog will become a carrier.

PRA is a serious disease that will cause blindness. You can, and shall, try to limit the spread through breeding restrictions. A first step may be that all results of eye examinations become public and that you compulsory examine all breeding dogs.

Berit Wallin Håkanson,
Opthomal veterinary at the Region Animal hospital of Strömsholm