Why Cats Pee Outside Their Litter Box
Why is my cat peeing in the house all of a sudden?
Your cat’s peeing behaviour may change over time, due to a number of reasons. Your cat may be peeing in the house all of a sudden for a number of reasons like stress, new environmental changes like another person or another pet. If your cat has been peeing outside their litterbox, either directly outside the box or in an area they have no business urinating in, it is probably one of two reasons. It is going to be a medical problem or a behavioural problem. If your cat was urinating in its litterbox properly, then suddenly stopped, something changed to upset the animal.
Why is my cat peeing just outside the litter box?
Understandably, you are probably frustrated. You may even be thinking about rehoming your cat. But before you do something so drastic, you should consider why your cat is peeing outside the litter box and how you can fix it.
Because changes in the environment are the biggest things that upset any animal, rehoming your cat because of a behavioural problem will only cause the animal more distress and more unpleasantness. While you might get away free with no more pee on your floor, the cat will be the one who suffers. Avoid rehoming at all costs. Why is my cat peeing in the house all of a sudden?
Read on for more in-depth reasons.

Medical Problems
If your cat is peeing just outside the litterbox, something is wrong. The first step for you is to take your cat and visit the veterinarian. By doing a simple physical exam and a urine sample, your veterinarian will be able to explain to you what the problem is and how you can treat it.
There are a few very common urinary issues that cats experience.
Bladder Stones
Bladder stones are extremely common with cats. These stones will cause irritation and even blockage of their bladder. And with bladder stones often come crystals. If your veterinarian thinks this is the problem, an X-ray will be taken to understand exactly what is going on.
Smaller bladder stones are able to be dissolved by changing your cat’s diet. However, larger stones will eventually need to be removed with surgery. If this is something your cat is suffering from, chances are they are acting out with their urination.
Cystitis
This ailment is an inflammation of your cat’s bladder. You will probably be able to tell this one fairly easily because there will be blood in your cat’s urine. However, the blood might only be detectable at a microscopic level, so the urine will need to be tested. Usually, cystitis can be treated by changing the cat’s diet and using pain medications.
Disease
Unfortunately, poor urination could be caused by metabolic disease. Liver disease, diabetes, kidney disease, and even thyroid issues may play a role in why your cat is not urinating where they are supposed to be. One of the reasons for this is that disease often increases the amount of urine produced by your cat.
If you have noticed your cat drinking a lot more water, and that you have needed to clean their litter box more often, you may need to do blood work to see what is going on inside your cat.
Urinary Tract Infection
This is a nasty one. While very rare with younger cats, a urinary tract infection can become a problem with an aged cat. A urinary tract infection could team up with any other medical condition to poorly affect the way your cat uses the toilet.
Because bacteria will have caused inflammation in the urinary tract, you will need to feed your cat antibiotics to treat the infection. The good news is that as an infection, it is curable and it can be fixed.
Behavioural Problems
I know it is scary to read all of these medical issues your cat could have, but the good news is that a cat peeing just outside of its litter box is generally a behavioural problem and not a medical one. A few things can account for this, like a dirty space, too much stress, and a change in scenery.
Stress
Cats get stressed out. They get stressed the same as we do. If your cat is urinating close to where it knows it should be doing it, chances are it is trying to tell you something. Perhaps you brought a new animal into the house and your cat is upset about it, marking its territory to let the other animal know who’s the boss.
Another reason your cat might do this when a new animal is introduced into the household is that it feels afraid to urinate inside the box while the other animal is on the loose. This is also true for a new human in the home, like if you have just had a baby or if someone new has moved in.
Do not forget that cats spend all of their time inside the house. They understand all of the changes that happen in their environment. To a cat, the house is its entire world. Anything that changes, they know about it.
If a new animal or a new person has just invaded your cat’s territory, you should make sure they have a quiet place to hide so they do not feel too stressed. Give your cat some time to adjust, make sure they have plenty of space, and you will likely see the behavioural problems stop.
Dirty Litter Box
Sometimes it can be as simple as a dirty toilet. Cats are extremely clean animals and if their litter box is dirty, they will not use it. Would you use a toilet that has been smeared with something gross? Of course not!
It could also be that the litter box is not comfortable enough for your cat to use. Perhaps the box is too small, perhaps it has been changed to a location your cat does not appreciate. It could even be that the litter box is covered and your cat doesn’t like it.
Finally, it could be that the litter box stinks. Even if it looks clean to you, your cat can smell old urine long after you have scrubbed it off the litter box. To mend this situation, simply clean your cat’s litter box. Like really, really clean it.
Why is my cat peeing in the house all of a sudden? The answer can be complicated, but there are a number of things that you can try to get them back into the routine. For me the answer was the litter box. I cleaned it out, and kept it clean on a daily basis and the behaviour changed. My cat is 24 so it was hard to figure it out. She also has some kidney issues and drinks a lot of water. So there are a number of things going on. She is blind and def so it’s really complicated.