Optic nerve hypoplasia

I have heard about a couple of cases of this condition cropping up in our breed recently.

While it doesn't seem to be common, I do understand that it can be detected if dogs undertake eye tests that the BVA run a scheme for.

I will ask the opthalmist next week when I take my Golden for his yearly eye test, but I understand that it can be tested for & BVA certificates issued if clear.



What is optic nerve hypoplasia?
Optic nerve hypoplasia is an uncommon defect in which the optic nerve fails to develop normally, leading to blindness. One or both eyes may be affected. Micropapilla refers to a smaller than normal optic disc, and is not associated with loss of sight.

How is optic nerve hypoplasia inherited?

The mode of inheritance is unclear.

What breeds are affected by optic nerve hypoplasia?
The condition occurs in the toy, miniature, and standard poodle and in the German shepherd. It occurs sporadically in other breeds as well. (See reference below for a comprehensive list.)

For many breeds and many disorders, the studies to determine the mode of inheritance or the frequency in the breed have not been carried out, or are inconclusive. We have listed breeds for which there is a consensus among those investigating in this field and among veterinary practitioners, that the condition is significant in this breed.

What does optic nerve hypoplasia mean to your dog & you?

Depending on the degree of hypoplasia (underdevelopment), an eye may be partially or completely blind. Usually if only one eye is affected, your dog will compensate for the decreased vision to the point that you are unaware of any abnormality. You may notice that the pupils of your dog's eyes are different sizes - the pupil of the affected eye will be larger.

If both eyes are affected, your dog will have some loss of sight or will be blind.

How is optic nerve hypoplasia diagnosed?
This condition is suspected when a dog is visually impaired from birth. Based on clinical and ophthalmoscopic examination, your veterinarian will determine if optic nerve hypoplasia is the cause. This condition must be distinguished from micropapilla, a normal variation of optic disc appearance where the disc is smaller but vision is normal.


How is optic nerve hypoplasia treated?
There is no treatment. With their acute senses of smell and hearing, dogs can manage well despite reduced vision. You can help your visually impaired dog by developing regular routes for exercise, maintaining your dog's surroundings as consistently as possible, introducing any necessary changes gradually, and being patient.

Breeding advice

Affected dogs and close relatives should not be used for breeding.

All pups should get a gene test before breeding. I think this is the only way to prevent this condition. This must be a part of our saint bernards.