My older cat is peeing everywhere. Can she have a UTI?

It is very worrying when they start doing that. Always, if you have concerns about the health of your cat, or if her behaviour has changed drastically, contact your vet. If the urine is stronger smelling than usual, it could be a UTI, but the only person who can make that diagnosis is the vet.

You need more than one litter box and make sure its potty trained, its probly spraying it feels territorial and doesnt like sharing its home, if you have another cat or there are cats around your neighborhood, its definitly spraying, go to the vet and get it newtered or spayed its kinda expensive so start saving up!! Good luck

If it is uncontrollable then they need to see a vet right away. If they are intact and spraying they need to be neutered.