There are a few reasons why your cat might refuse to go in the litter box, but usually the problem can often be solved easily. The most likely explanation is scent (the litter box is very dirty or has a very strong or unpleasant odour), alternatively you’re using a new litter which your cat is not used to, or you could have a non-neutered male who is securing his territory by urinating everywhere.
It could just be a phase but it might indicate a bigger problem, so speak with your vet to be sure. Before making that call, just check for a few things that will help them with a diagnosis:
Is the litter box clean?
Many cats refuse to do their business in a litter box that is already dirty. We recommend daily cleaning but some picky cats will require twice a day.
Does the box smell?
If the urine is starting to eat into the plastic, maybe it is time to invest in a new box. To prevent urine from touching the bottom of the box, make sure that the litter is around 7.5 cm (3 inches) deep. High-quality clumping litter will better control odours
Enough box space?
Experts agree that you should have one more litter box than the number of cats using them. The length of the litter box should be one and a half times the length of your cat, while the width should be equivalent to the cat’s length.
Has anything changed?
The arrival of another cat, dog or child can change a cat’s routine and cause anxiety. House moves and renovations can also create stress, resulting in a change of behaviour.
Does the urine look or smell different?
For any sudden change in your cat’s hygiene habits, please contact your vet immediately. This could be a serious problem and require medical care. Cats are sensitive to urinary tract infections and are often experts at masking their pain.