Dear Dr. John,
Our mixed breed dog is almost 10, and he seems to struggle somewhat when we walk him at night. He does not seem to notice certain things or movements the way he used to. We took him to our vet who pointed out cloudiness in the middle of his eyes. She told us that it was a common aging change in the lenses of the eyes for which nothing could be done. We were informed that it was not cataracts. What is this condition? Will this progress? We were told he would not go blind. Is there anything that might have been done to prevent or delay the eye changes? C.T.
Dear C.T.,
Cloudy dog eyes can be a result of various conditions or changes to the structures in the eye. In older dogs, the most common causes are lenticular (or nuclear) sclerosis or cataracts which both involve changes to the lenses. From what you have written, I am quite certain that your dog has the former condition. Roughly 50% of older dogs eventually develop this change in the eyes without negative consequence and there is no way to prevent or delay it from happening.
Your veterinarian was correct in all that she apparently told you. Nothing can be done to reverse the changes and your dog will continue to see and not go blind. What your dog has is a change to the density of the lens which allows the dog to see but the vision may be a bit hazy resulting in some perception changes.
Cataracts, on the other hand, cause reduced vision and often progresses to complete blindness. Cataracts can present at various ages and be due to different causes. Unlike with sclerosis of the lenses, cataracts are surgically operable, and vision can be restored but there are many factors to consider before considering such an approach. Other causes of cloudy eyes in dogs can be due to glaucoma, corneal ulcers, corneal dystrophy, keratoconjunctivitis sicca, uveitis, and pannus. Enjoy your dog in his older age!
Dr. John de Jong is President of the World Veterinary Association. He owns and operates the Boston Mobile Veterinary Clinic and can be reached at 781-899-9994.