Ok 2 questions whats the difference between CEA and PRA and are they tested with the same test? Also if a dogs parents are clear on both does that mean no puppies produced will ever be effected or carriers?

CEA is a disease essentially affecting the scleral and choroidal layers of the eye. The disease is bilateral, which means it affects both eyes, but not necessarily to the same degree. In it's mildest form, vision is not impaired, but blindness will occur in it's severest form. The disease is not progressive, unlike PRA, which means that whatever the degree of affliction, it will not deteriorate.

Progressive retinal degeneration (PRD) is also known as progressive retinal atrophy (PRA) and refers to retinal diseases that cause blindness & is  a slowly progressive degeneration or death of the retinal tissue.In the retina, cells called rods are involved with black and white or night vision and cells called cones are involved with color or day vision. Progressive retinal degeneration may effect either the rods alone, the cones alone or both the rods and cones together.

If a puppy is screened clear of CEA it will never develop it but it can be a carrier, only a DNA tested clear dog can never produce a CEA affected puppy, however unless the dog in the breeding is also DNA tested clear carriers can be produced

PRA can occur at any age(rare under the age of two hence the ISDS requirement for all dogs & bitches to be tested at 2 & then yearly afterwards. PRA has been found to have developed in later life & as yet in BCs there is no DNA test so one cannot guarentee that clear parents will not produce affected dogs

The ISDS have reduced PRA & CEA to less than 2%(I think) of tested dogs from a much higher %(actual % escaoes me at present)by taking affected dogs & their parents out of the gene pool