Weeing outside of the litter tray can be due to a variety of reasons. It can be to destress - following the arrival of a new baby for example - for fear of reassurance - following a move - or to mark territory. It can also be the type of litter used which poses a problem (dirty litter, closed container, the smell or the gas given off).
Whatever the reason, you should never scold or punish your cat, whether you catch them in the act or not. Above all, do not shove their nose into the “accident”, it would be like saying "What, is that all? Do it again, but better! ". To do this would only amplify the problem.
Identify the root of the problem: why aren’t they using the litter tray?
The first thing to do is to identify the cause of these accidents. Why? What’s changed? What happened in the days before the first accident? If nothing has changed in the family dynamic, no move, no new furniture, no new food, no change of litter type, etc., then we must look at the owners; are they stressed, tense, revising for an exam, in conflict, has their routine changed, are they suffering from a health problem, etc. When stressed, cats will try to get rid of this stress. By urinating, the feeling of release can be temporary respite. In addition, the smell of urine comforts and reassures your cat. So, this is where it all begins. But why outside of the litter box?
Very simply it could be to warn you that something is wrong. It is not always easy to know what exactly, especially since the cause could be traced back to a few weeks before the first incidents (the time that the stress sets in).
Other causes which have the same effect: cystitis, stones, urinary infections, diarrhoea or constipation, and other excretory problems. Cats may make a connection between the litter tray and the pain and believe that the tray is the cause of the illness. So, they will go elsewhere to relieve themselves.
Cats may also refuse to share with other cats, or to go to on already soiled litter. You must always have one more tray than the number of cats you have and to make sure it is always clean. Clearly, there are many causes which are sometimes tricky to identify.
Once the cause has been identified, if it can be resolved then everything should go back to normal in time.
However, sometimes that's not always possible. Give your cat enough time to adapt, but no longer than a few weeks. If they continue to soil outside of the litter tray, then the problem has not been correctly identified. You need to look for the causes again, as your cat has not adjusted to this change.
Reassure, never punish
In any case, even if it's annoying to have to clean, do not reprimand your cat, wait, stroke them if they ask for it, but don’t follow them around either. Mollycoddling a cat that has a problem will not be looked upon fondly. They need to feel calm, which is why it is important to wait for them to come to you.
Change the way you behave towards your cat. Make them feel like a partner, being sweet and speaking comfortingly is enough. By feeling loved, not rejected and friends with their owners, independent if they want they will ask to be stroked and calmed if they wish, it’s more than likely that this behaviour will stop.
In the case of territorial marking, sterilisation may help change their behaviour (but this is not a solution: behavioural therapy is required).
If you are unsure of the problem or are having trouble identifying or solving it, consult a professional behaviourist. With a professional perspective and distance, they will help you get through this difficult stage by explaining what is happening and why. As well as identifying the problem, they will more importantly be able to make sure that not using the litter tray isn’t a hidden sign of anything more important.
If necessary, the behaviourist will develop a therapy with you, and / or suggest a check-up with your usual vet to rule out any kidney or bladder problems etc.
Patience is key in such situations.