Thank you again for that information about wee Katie.
Now you have actually noted quite a few wee factors in her life that could be triggering this behavior. It will be a case of channeling our inner Sherlock Holmes to tease apart her situation and pinpoint which is pushing her into this inappropriate urination.
As I am sure you can appreciate, cats do not suddenly urinate outside the litterbox for no reason. This is because it is a behavior that goes against kitty instinct (to hide and bury waste from predators). Urinating out of the appropriate spot in a cat is like a message (since cat’s don’t do email). Therefore, we do have to appreciate that Katie has initiated this behavior in response to something that is amiss.
First off, I would put litter box concerns lower on our list of triggers for her. The reason is because she is still using it for feces, which suggests that she is not suffering an aversion to the box or recent litter changes you had made. So, at the moment, I wouldn't be focused on that differential for her.
Considering the issues outside the box that could induce this behavior, we need to think about medical and stress/behavioral based reasons for her actions. And if she was borderline on her thyroid hormone levels, I would be a wee bit concerned that perhaps the balance has tipped this week and the polyuric (increased urination) effects of thyroid disease could be making her feel 'not right' and thus may be leading to this inappropriate urination. Alternatively, we cannot rule out that perhaps something else within the body (ie kidney function or even a bladder infection) is disturbing her health to a level that is making her demonstrate this behavior. And while I do think having a urine sample should be checked to rule out medical causes for any elderly inappropriate urinating cat, I'd say that this would be even more important for Katie. Furthermore, it might be an idea to consider moving up that thyroid level check to make sure that this isn't an early warning sign that she isn't as stable as she should be.
If medical reasons can be excluded, then we do need to assess her current environment. If there has been a lot of change going on for the past 18 months, then we'd have to ask ourselves why her behavior started this late. (though if the bed has been a more recent addition then that might be enough). You are right to have the Feliway plug in for her to reduce stress but remember it is only a coping aid and not a cure-all for stress. Therefore, we do need to see if we can pinpoint what might have set her off this week and if that can be removed, then we may see her signs settle. Otherwise, you can consider including other treatments with the Feliway to further try and allay stress for her. Other options would be nutritional supplements like Zylkene, which use a casein protein to soothe anxious cats. As well, there are treats like Composure (LINK) and even a Bach Flower Remedy (LINK) for cats (though not as well tolerated as the other agents and isn’t as feline specific as the other de-stress agents are). It can sometimes be a case of minimizing triggers while finding the right combination of support to allay stress for them.
Furthermore, at the same time, you need to make sure that you are taking steps to discourage her associating the bed/non litterbox places with being somewhere she can go, by making sure the areas are cleaned afterwards. I would advise using an enzymatic odour neutralizing cleaner (LINK1 LINK 2) wherever she has urinated because while normal cleaners will eliminate the smell to us, she may still be able to smell her own scent and thus choose to go there again. Her scent will be the red flag that its 'ok to pee here'. To make sure you get everywhere she has been, you can use a black light to illuminate any areas that she has urinated on (example).
Overall, in Katie's case, I would strongly advise ruling out medical causes for her sudden lapse in litter box manners. A urine sample is a quick and cheap way to check her kidney function and just give you an idea of an underlying bladder infection is present. As well, since she is a delicately balanced hyperthyroid kitty, I'd suggest that rechecking her thyroid level now would be prudent. If you are able to check these, they will aid you in determining if this is an early hint of something being amiss with her health. And if they are clear, it will allow you to focus on the stress based differentials and work to get her settled and back to urinating where she should.
I hope this information is helpful.
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