We get questions about cataracts a lot, especially in older dogs.
There are several things that can cause your dog's eye to be hazy. Sometimes it's part of the normal aging process and sometimes it's more serious.
The most common cause in older dogs (over the age of 7) is nuclear sclerosis, also called lenticular sclerosis. This is an age-related change in the lens which occurs in most senior dogs. Continuous production of the transparent fibers which make up the lens eventually results in compression of the existing lens fibers in the center of the cornea. This has no or possibly little effect on vision and is translucent, meaning that light will pass through the haze and the back of the eye can be seen through it. In contrast, a cataract is a lens opacity so light cannot pass through the density and the back of the eye is obscured. Cataracts and nuclear sclerosis can be easily differentiated on a routine veterinary examination. The most common causes of cataracts are genetics (breed-related), diabetes, previous trauma to the eye, and retinal degeneration. There is no treatment for nuclear sclerosis but because the condition does not affect vision, no treatment is needed. Small cataracts can be monitored for changes in size. Cataracts can be treated with surgery by a veterinary ophthalmologist if they threaten vision.
In addition, the eye can appear hazy due to a problem with the surface of the eye called the cornea. This is usually due to corneal edema which is fluid accumulating in between the layers of the cornea. Corneal edema can occur due to an abrasion (called an ulcer), glaucoma (increased pressure in the eye), and a problem with the layers of the cornea that allows fluid to accumulate there. Corneal edema is a more serious condition, so if your pet's eye is painful, red or they are squinting you should seek veterinary attention right away.
Make an appointment today if you are concerned about your pet's eyes.