Many of the DNA tests available for Aussies examine genes associated with eye diseases and defects (cataracts, Collie eye anomaly, canine multifocal retinopathy 1, cone degeneration, and the progressive rod-cone degeneration form of progressive retinal atrophy.) Given all these tests, some people wonder why it is necessary to do regular eye exams. The tests tell us what the genes are, right? Yes, they do. But that that is only part of the picture.
While the DNA tests are a valuable tool for breeders. They can help to reduce disease risk, prevent producing puppies who will have these conditions, and - over the long term - reduce frequency of these mutations in the breed. However, DNA tests do not tell us everything we need to know about a dog's risk for having or producing all hereditary eye diseases. The tests don't cover every eye disease found in Aussies, including iris coloboma and hypoplasia, distichiasis, persistent pupilary membrane, scleritis, and PHPV/PTVL, none of which presently have tests. Nor is there a test for the 30% of inherited cataracts not caused by the HSF4 cataract mutation.
Some of these diseases without tests can be detected in a puppy exam but others don't arise until later in life. All Aussie puppies should have a first eye check between 5 and 7 weeks of age, even pet puppies. If you don't check you may have missed something important and pet people may not realize they should notify you I something is wrong. Breeding dogs should be examined yearly or at least within a year prior to any breeding. Because having one or two copies of the HSF4 mutation is only a risk factor, detecting the dogs that actually get this type of cataract requires exams.
Do the DNA tests but eye exams are still a very important part of keeping our breed healthy.