Catalina Pet Hospital
One of the more annoying things that can happen while living with a cat is if they stop using their litterbox consistently, aka inappropriate elimination, urination, or defecation. Many cat owners assume the cat is doing so out of spite or anger. This is NOT the cause in most cases.
Cats of any age that are urinating outside of their litterbox may be having a health issue such as a urinary tract infection, bladder irritation from crystals or stones, or rarely bladder cancer that is causing them to have an increased urgency to urinate. Your veterinarian can collect a urine sample from your cat for analysis, take an x-ray, or perform an ultrasound to help determine the cause. Your older cat may even have arthritis causing them to have a difficult time entering the litterbox.
Litterbox hygiene that has been neglected can be a major source of avoidance for a cat. Daily litter scooping helps prevent a litterbox from becoming too odorous for your cat to use. Covered litterboxes can also cause bad smells to build up. Make sure you have at least one litterbox per cat, in different quiet areas of your living space, that allow easy access. Some cats are very picky about their litter and may stop using the litterbox if you suddenly change brands or types of litter.
If you have multiple cats, your cat may be bullied by the other cats and not feel safe using the litterbox. Anxiety or stress can also cause a cat to not go into their litterbox, such as strangers or workers in the house, new pets or household members, etc. Stress can be helped with pheromone sprays or diffusers, special calming diets, their own special cat room, and/or a consistent routine. Some cats may need prescription medication for their anxiety.
Your best course of action is to figure out the real cause as soon as possible so that the inappropriate urination does not become a habit. Your cat will thank you and be quite happy as well!
(The above cats are available for adoption from Pawsitively Cats )