My 14 year old cat was diagnosed with arthritis last August over the pelvic area and spine. Unfortunately for the past month he has been peeing all over the place. I have tried all sorts of things to help his situation such as having several litter boxes which are completely flat, appropriate food and giving him vitamins for his joints. I also got him groomed as he no longer cleans himself, this was suggested by our vet. At this stage I don't know what to do that might help reduce the peeing part as he no longer uses any of the litter boxes. Any suggestions please? Or could it be something else, such as kidney failure? :(
First, thank you for caring for your kitty into his senior and geriatric years. You have done the right things by offering him multiple, flat litter boxes throughout the house so he doesn't have to step high to get in or out. If you have two floors to your house, be sure there are litter boxes on each floor (but I'm sure you've already done this).
Yes, you definitely need to take him back to the vet to see if there is an additional problem. If you live in a place where there are veterinary specialists with immediate diagnostic tools, you should ask your vet for a referral.
If the vet (or specialist) doesn't find anything else, they can give you medicine for your cat's arthritic pain. The usual go-to medication for many geriatric cat problems is prednisolone, a steroid similar to the human prednisone. I had to give this to my cat, and it helped him feel a lot better.
Be careful with giving your kitty joint vitamins. These are unregulated, so be sure to buy a well-known brand. What's even better is a prescription food that already has these supplements in it. I know Hills has a joint formula food. You have to purchase these types of foods from your vet, and the food is more expensive.
If your cat is overweight at all and is not diagnosed with additional problems, your first goal should be to get him to a better weight. Even the loss of one or two pounds for an overweight, arthritic cat can make a lot of difference.
Also, you could try picking him up and placing him in the litter box every few hours to see if he will go. This isn't likely to work but is always worth a try.
I wish I could give you more of a "magic" answer, but your kitty is at that age where the body starts to degenerate more and more. There is no cure for arthritis in cats, but you can manage the pain so your cat has a much better quality of life.
I truly wish you and your kitty the best.