Dear Most Esteemed and Knowledgeable Kitties:
Hello, and thank you for your time. My sweet kitty has always “demanded” tuna. Well, he’s now getting older and I believe he is nearly blind, because he continually bumps into things. I think this was caused by the mercury in the tuna he loves so much. I feel guilty beyond words. But mainly, I’m wondering if there is a way to reverse the effects of the mercury poisoning, other than just not giving tuna to my cat anymore? Can I help clean his system somehow? Will it reverse the blindness? Please, please help me. Thank you!
Siouxsie: OK, so there are a few common causes of blindness in cats, and zero of them have to do with mercury poisoning — so there’s no need to feel guilty about feeding your cat tuna.
Thomas: What you really need to do, Janice, is get your cat to a vet as soon as you can, because some of those common causes of blindness can be reversed with quick medical treatment.
Bella: As your cat gets older, he’s going to be increasingly susceptible to those causes of blindness, so it’s super-important to take older kitties to the vet at least once a year (and we actually recommend twice-yearly visits for cats over the age of 13).
Siouxsie: By far the most common cause of sudden-onset blindness is high blood pressure, which causes the retina to detach from the back of the eye. The retina is the part of the eye that turns light into images our brain can process.
Thomas: High blood pressure can be managed with medications just like humans take but in cat-size doses. Do not give your cat your own blood pressure medication, though, because the dose is much too high and could cause very serious problems up to and including death.
Bella: High blood pressure doesn’t just appear in cats for no reason, though. It’s usually caused by kidney disease, hyperthyroidism or heart disease. Again, all three of these illnesses can be managed with proper veterinary care.
Siouxsie: Untreated diabetes can also lead to blindness by causing damage to the retina.
Thomas: Cats can develop cataracts, opaque spots in the front of the eyeball that block light and blur vision. Usually cataracts are pretty obvious because they make the eyeball look cloudy.
Bella: Cats can develop glaucoma, a buildup of pressure inside the eyeball, which can also lead to blindness. The type of glaucoma cats get is extremely painful, but your cat probably wouldn’t show you he’s in pain.
Siouxsie: Other causes of blindness include taurine deficiency (not as common now that taurine is added to cat foods, although it could be a problem for your cat if you’ve been feeding him human tuna instead of tuna cat food), side effects of certain medications, and even cancer.
Thomas: The bottom line here, Janice, is that your cat needs to go to the vet. Only your veterinarian can tell you why your cat is blind and what, if anything, can be done to reverse it.
Bella: Even if your cat’s blindness is permanent, he can still enjoy a great quality of life. Check out Mama’s Catster post for some tips on living with a blind cat for more information.
Siouxsie: What about you other readers? Have you had a cat who suddenly went blind? What was the reason, what did you do about it, and did your kitty’s vision get restored as a result? Please share your stories in the comments.