Stephanie wrote in with a question about her dog’s cloudy eyes:
“I’ve noticed lately that my dog’s eyes look cloudy. He’s 11 years old and seems very healthy but I’m worried he’s getting cataracts. Is my dog going to go blind?”
Gazing into your dog’s eyes increases oxytocin levels for both you and your dog (Nagasawa, M., et al., 2015). If you practice mutual eye-gazing regularly like I do with my dogs, I can understand how the cloudiness in your dog’s eyes could be worrisome!
Cloudiness in a dog’s eyes can be one of several things…
- Corneal disease–The cornea is the very front part of the eye that is normally clear.
- Uveitis–Inflammation inside the eye.
- Lens changes–The lens is inside the eye, behind the colored tissue of the iris, and is seen through the pupil.
You should definitely have your veterinarian check your dog’s cloudy eyes. It can be difficult to tell exactly what’s going on when you’re looking at the eyes at home.
Your vet can use an ophthalmoscope to determine the location of the cloudiness. The vet may recommend checking the pressure inside your dog’s eye with a special instrument called a tonometer. High or low eye pressure may indicate inflammation or glaucoma inside the eye.
The cornea is the clear front part of the eye. It needs to be perfectly clear so light can pass through to the retina. Various diseases can make the cornea appear cloudy including:
- Corneal Ulcers–trauma, stray hairs, and inherited corneal abnormalities lead to corneal ulcers.
- Corneal Endothelial Dystrophy–disease affecting the inner surface of the cornea. Can be a genetic disease or secondary to inflammation
- Lipid Keratopathy–lipid (fat) deposits within the cornea that often appear as white spots or streaks.
- Glaucoma–increased pressure within the eye can make the cornea get cloudy.
Uveitis is a condition caused by inflammation on the inside of the eye. Tick-borne organisms (like Ehrlichia), as well as fungal, bacterial and viral infections, can cause uveitis. Trauma to the eye can also cause uveitis. Uveitis can occur in one or both eyes at the same time.
Dogs can get cataracts when they’re young or old. Certain breeds are prone to congenital cataracts which affect them at young ages.
The older a dog gets, the more likely he is to have cataracts. One study showed that about 50% of dogs over the age of 13.5 years had some degree of cataracts in their eyes (Williams, D., Heath, M., & Wallis, C. 2004). But many older dogs with cataracts still have a functional level of vision.
Diabetic dogs form cataracts at a much higher rate than any other dogs. In fact, one study found that 80% of diabetic dogs developed cataracts within 16 months of diagnosis (Beam, S., Correa, M., & Davidson, M. 1999). Diabetic dogs almost invariably have other symptoms, including excessive drinking and urination.
Nuclear Sclerosis of the Lens
Considered a “normal” aging change, nuclear sclerosis occurs when the central nucleus of the lens is compressed by normal proliferation of lens fibers. Veterinary ophthalmologists tell us that nuclear sclerosis does not cause significant vision loss in dogs.
According to a study done in 2004, 50% of dogs over age 9 years have eye lenses affected by nuclear sclerosis (Williams, D., Heath, M., & Wallis, C. 2004). In my practice, nuclear sclerosis is the most common thing I find when people ask, “Why are my dog’s eyes cloudy?”
Your veterinarian should be able to diagnose nuclear sclerosis with a simple exam with an ophthalmoscope. The good news is that no treatment is necessary for nuclear sclerosis!
You can ask your own question on our ASK A VET page!
Beam, S., Correa, M. T., & Davidson, M. G. (1999). A retrospective-cohort study on the development of cataracts in dogs with diabetes mellitus: 200 cases. Veterinary ophthalmology, 2(3), 169-172.
Nagasawa, M., Mitsui, S., En, S., Ohtani, N., Ohta, M., Sakuma, Y., … & Kikusui, T. (2015). Oxytocin-gaze positive loop and the coevolution of human-dog bonds. Science, 348(6232), 333-336.
Williams, D. L., Heath, M. F., & Wallis, C. (2004). Prevalence of canine cataract: preliminary results of a cross‐sectional study. Veterinary ophthalmology, 7(1), 29-35.