The Australian Shepherd also can be affected by eye defects with varying degrees of hereditability. Progressive Retinal Atrophy (PRA) is a very serious disease which is caused by a recessive gene. The end result is complete blindness. We do know that affected dogs inherit the gene from both parents, so both parents are carriers. All the puppies from an affected dog will have the disease or be carriers. This disease may not show up until later in the dog's life wich is a reason for yearly eye exams by a certified veterinary ophthalmologist.
A regular veterinarian can not diagnose most eye diseases. When a dog is examined by a certified veterinary ophthalmologist and diagnosed free of disease the owner will receive a form. The owner can submit this form to CERF to receive a number declaring the dog free from eye defects. If CERF is not used, the owner should be able to provide a copy of the certified ophthalmologist forms to potential buyers.
Another eye defect diagnosed in the Australian Shepherd is Collie Eye Anomaly (CEA) which is also hereditary. Again a certified veterinary ophthalmologist needs to check the eyes of all dogs used for breeding.
A defect that can be seen without special equipment is the Iris Coloboma, and it is especially noticeable in blue eyes. The inheritance of this defect has not been identified although studies have shown it occurring in families. In these eyes the pupil appears to extend into the iris (colored part of the eye) often with a jagged edge. The ASCA (Australian Shepherd Club of America) breed standard calls for the pupil to be well defined and perfectly positioned. If the pupil is not perfectly round and in the center of the eye, the eye is not normal. Most dogs with an Iris Coloboma appear to function normally, but there is evidence that this is inherited and affected dogs should not be bred.
Juvenile cataracts are a serious defect as they also end in blindness. This is a disease and different than old age or senile cataracts. Again a certified veterinary ophthalmologist would need to diagnose the disease in its early stages.
Other inherited diseases have been observed in the Australian Shepherd to a lesser degree. ASCA strongly recommends that all puppies be sold with a guarantee against hereditary defects and all breeding stock be OFA Certified and have a yearly "clear" eye check.
