Hi Brittany,
Thanks for your question.
Whenever our pets are eliminating inappropriately, whether it be urination or defecation, it can be caused by two things: medical or behavioural reasons. So the first thing we have to do is rule out medical problems.
I recommend you see your veterinarian and perform diagnostics to make sure there is no medical issue causing this. In this case, the physical examination is very important. If there are any joint problems compounded by obesity, it could be very difficult for your cat to step over the lip of the litter box. If she is large, she may not fit into it well and this can make things uncomfortable.
A critical issue in your case is whether the behaviour has become a learned behaviour now despite the reason it started in the first place. So it could have started with obesity and arthritis which if resolved, still may not solve the problem because she has simply learned to defecate outside the box.
If no medical condition is found, then we have to consider behavioural reasons as a source. Cats are very in tune with their environment and so there are so many stimuli that can cause them to become anxious or change their behaviour. For example, I remember a patient that stopped going to the litter box because an owner started storing luggage near the litter box. Cats can also perceive things that we can’t, so a high-pitched sound that doesn’t bother us, may bother them and cause them fear around the litter box. Now you may go hunting for these things, but in the end, it’s rare to find. It doesn’t take much for a cat to start eliminating inappropriately and once they do, the reason they started doing it may be gone but they are now just continuing. The longer you let this go on, the more it’s going to be ingrained and difficult to resolve.
There are some strategies you can employ to focus their attention on the litter box. You’ve already mentioned one of them and that is cleaning the litter box daily.
You can also start putting treats near the litter box but I always tell people not to let the cat know you’re putting them there. This way they just happen to find them there. They may start visiting in the litter box just to see if they’ve shown up again and since they’re there, they might as well use the litter box.
You can also place litter box in various areas of the house. Keep in mind that cats can develop issues like arthritis which can make it difficult for them to go up and down stairs and this may be the cause of why they’re not visiting the litter box.
When a cat is really overweight and large, they may no longer fit in the litter box and it may not be comfortable to use it. I often have owners buy a large bin, cut the sides really low, put it in a garbage bag and sprinkle litter on top of it creating their own litter box with a much larger surface area and low sides to it so it’s very easy to step in and out. This is what I recommend strongly in your case.
There are also products that you can sprinkle in the litter that is supposed to attract them to it. These can work in some cases but not in others.
If anxiety is the cause, you may be able to improve this with environmental enrichment. Get your cat playing more and engaging it with toys. This will reduce stress.
If they are eliminating in a particular spot, like on a bed or in a bedroom, you can restrict access to this area. Always clean the area where they have been eliminating very thoroughly. Even a small amount of debris or odour will make them return to that place and think it’s an appropriate place to eliminate.
Lastly, a lot of cases do take medication to solve these issues. I would have to say that anxiety, in general, is usually the cause of the problem. Whenever I say this to clients, I always get the same response. They say: you clearly don’t understand my cat, he or she is not stressed. But what clients don’t understand is that although you’re providing a very nice home for your pet, we have to remember that these were animals that lived in the outside environment and engaged their world by hunting and hiding. Many cats can develop stress just by being an indoor cat. You can speak to your veterinarian about anti-anxiety supplements and anti-anxiety medication to use as a trial if the aforementioned strategies do not work.
Thanks for your question and good luck!
Dr. Clayton Greenway