Trouble with my 18 year old cat!

My wonderful cat is 18 years old. She is in good health, although she is starting to go blind and deaf. However, she still can chase after my dog and rule the house!!

Now to my problem. She is starting to lose control of her bowels. She urinates in places that "looks" like where her litter box is, and when she lays on our bed or couches she leaves behind feces and particles. We are good at keeping up with her, but its starting to become worse.

I know they have doggie diapers, do they have the equivalent for cats? Does anyone have experience with this and can give me some insight?

Thank you in advance for any help!!!

(If this is the wrong place to post, I apologize and please direct me!!)