Nibble on This: It’s True—Carrots May Improve Your Dog’s Eyesight!
While there is some hint of truth in the concept, eating bushels of carrots will not give your dog (or you) super vision. Carrots are indeed a nutrient-rich source of a variety of vitamins and minerals, including beta-carotene. Beta-carotene is actually a pigment that gives the signature orange (or sometimes yellow or red) color to carrots and other vegetables. It is the beginning form of vitamin A (called retinal) that is necessary to maintain good vision - especially in dim light.
How Does Beta-Carotene Help?
When your dog eats foods containing beta-carotene such as carrots, it is absorbed by the intestine and transported to the liver. It is then combined with fats in the diet, converted to vitamin A, and stored there until it is required by the body. When called upon, it is released through the bloodstream and goes to the retina of the eye.
The retina is the interior lining found in the back of the eye and it is critical for normal eyesight. The retina is made up millions of cells called rods and cones. These cells are sensitive to light and use vitamin A to tell the brain (via the optic nerve) what is being seen. The rods are most important in low-light situations, and the rods are sensitive to low levels of vitamin A in the body. So, if an animal has a deficiency of vitamin A, eating more foods that contain beta-carotene could help improve eyesight (especially at night).
Beta-Carotene/Vitamin A in Your Dog's Diet
Carrots are not the only source of this important nutrient in your dog’s diet. Ingredients such as liver, eggs, sweet potato, spinach, and broccoli also contain beta-carotene. Vitamin A and beta-carotene are also created synthetically and added to pet food to make sure the levels provided are adequate for daily nutrition.
There is, however, such a thing as having too much vitamin A in the diet. Dogs that have too much in their diet (hypervitaminosis) can develop bone problems and muscle weakness.
Thankfully, reaching a toxic level of vitamin A would require a very high dose for a long period of time, and giving your dog a few carrots now and again isn’t going to come close to providing an overdose. But if you do choose to give your dog carrots as an occasional treat, it's best to cut them up into smaller pieces to reduce the risk of choking or gastrointestinal discomfort.
While feeding your dog carrots occasionally or buying dog foods that contain sources of beta-carotene can provide health benefits, there is not much chance of your pet's eyesight becoming even better than before. That said there is a small chance of diminished eyesight caused by injury, cataracts, glaucoma, etc., being improved by beta-carotene supplementation; beta-carotene has even been shown to prevent cataracts and other eye diseases.