The signs of hyperthyroidism in cats are subtle and can be confused with symptoms of other diseases. If your kitty experiences sudden weight loss but is drinking and eating like a small horse, have the vet check her thyroid levels. Left untreated hyperthyroidism can mask other diseases and affect eyesight.
How Hyperthyroidism Affects Eyesight
Hyperthyroidism won't affect your cat's eyesight directly, but it can cause hypertension -- high blood pressure -- which can directly affect vision. Most commonly hypertension caused by hyperthyroidism results in retinal detachment due to excess protein in the blood and problems with blood circulating properly in the retina.
Symptoms To Watch For
Red flags you might notice if your cat has hyperthyroidism include increased appetite and thirst, frequent urination, weight loss, diarrhea, vomiting and hyperactivity. You might also notice a change in the appearance of your kitty's usually gorgeous coat, as it may become matted and appear greasy or develop dandruff. If you see any of these symptoms, take your cat to see her vet immediately. Always consult an experienced veterinarian regarding the health and treatment of your cat.
When hyperthyroidism is diagnosed and treated properly, cats usually recover wonderfully. There are a handful of effective treatment options like anti-thyroid medications which control the condition. If your cat's health allows and you want a permanent solution, your vet may recommend surgery to remove the thyroid gland or radioactive iodine treatment, which the American Association of Feline Practitioners reports to be the treatment of choice. Iodine treatment is favored because it's curative, doesn't cause side effects and doesn't involve anesthesia.
Can It Be Prevented?
Unfortunate as it is, there is no way to prevent hyperthyroidism. Early detection and treatment play a big part in limiting the effects of secondary conditions like high blood pressure. Preventing retinal detachment and resulting blindness depends on treating and controlling blood pressure. Detachment can be avoided if your vet catches high blood pressure early and treats it immediately. If the retina has already started to detach, treating high blood pressure can reverse the condition, but in their book on veterinary treatment for cats Trevor and Jean Turner note that if the retina does not reattach by itself within 48 hours, partial to total blindness is likely.
- Nursing the Feline Patient; Linda E. Schmeltzer and Gary D. Norsworthy
- ASPCA Complete Guide to Cats; James Richards
- Clinical Endocrinology of Companion Animals; Jacquie Rand, et al.
- WebMD: Hypertension (High Blood Pressure) in Cats
- Cornell University College of Veterinary Medicine: Hyperthyroidism in Cats
- Veterinary Notes for Cat Owners; Trevor Turner and Jean Turner
- John Foxx/Stockbyte/Getty Images