I researched this a bit when a friend of mine's bitch came up with this disease. I thought that it should show up and be there through the life of the dog. I did not understand it to be a disease that might just appear one year and then on. This friend went to a different canine ophthalmologist and the dog was examined (as well as mother who had passed CERF in the past) and both dogs were cleared. The second vet was amazed that anyone would have said geographic retinal dyplasia. It should not go away.

If the dog has had clear exams in the past and then one failing one, I would retest with a different vet.

I believe that there is a test now for RD . You could check the parents, if you still have them, to see if they carry the gene. If they don't, then this should not be the inheritied type.