Hello again, Lea.
I was hoping to get some additional information from you, but, I didn't want you to wait any longer for an answer.
I'm assuming your cat is fixed and if not, this can be part of the problem.
For one cat, you should have two litterboxes that are open, not covered, and use unscented litter. You can also add a litter additive called 'Cat Attract' to your regular litter and this contains herbal attractants, to encourage use of the litterboxes.
When cats pee on items outside of the litterbox, this can indicate a urinary or bladder issue, like an infection, crystals (tiny, sand-like particles that form in urine that is not acidic enough), and this is causing discomfort. They begin to associate the litterbox with that discomfort and try to avoid it and go on soft items. They feel if there is something soft under their paws, it won't hurt when they pee. If you have a male cat who may have a UTI (urinary tract infection) or crystals, this could lead to a urethral blockage, and in male cats, this is a medical emergency. Females tend to get blockages less, due to their wider urethras, but there are other underlying medical conditions, like cystitis, interstitial cystiis and bladder or kidney stones, which can cause pain, too. Here is more information about Feline Lower Urinary Tract Disease (FLUTD):
If stress/anxiety may be the cause, put a Feliway plug in diffuser in the room (or rooms) where he spends the most time. The plug in resembles a plug in air freshener, but has no scent to humans; only cats can detect their calming pheromones. Here is more information:
You can find Feliway products in major pet supply stores, some Walmarts, and some vets carry it or you can order it online.
It's also very important that you clean the soiled areas with an enzyme based cleaner for pet/organic stains and odors. Some well-recommended ones are Nature's Miracle, Zero Odor, Odor Mute, and many more you will find in your pet supply store. Just make sure it says 'enzyme-based.' Once you clean the soiled areas, your cat will no longer be able to smell where s/he has gone before, and won't be tempted to do it again.
For the moment, you can cover all your couches and sofas with a big plastic or vinyl tarp (it won't be pretty, but, you can remove it when you have visitors and put your cat in another room with a closed door) and that should stop him from peeing on them. You can also put double-sided sticky tape on the tarps covering the sofas, because cats hate the feel of 'sticky' under their paws.
Your next best step would be to have your kitty evaluated in person by a vet, a urinalysis and urine culture should be done and then you will know more.
You cat may feel the need to mark territory if there are any unneutered or neutered strays hanging around outside your house and s/he feels threatened. If this is the case, you can get Feliway spray and use it on window sills, window frames (inside) and inside doorframes of doors leading to the outside. This will make your cat feel that he/she has already marked inside.
I always like to reserve a suggestion of a prescription medication for inappropriate elimination as a last resort, but if you must, discuss the alternatives with your vet and ask about Clomicalm. This is well-recommended, but there are various other medications to choose from. Here is more information:
I hope all will be well with your kitty and please let me know what the vet's findings are. Thanks!
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