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Why Is My Cat Peeing In The House All Of A Sudden?

If you’ve had a housetrained cat who is suddenly peeing in the house, you are likely concerned and wondering why they’re doing it. Besides, it’s inconvenient, to say the least! Why would a cat suddenly start peeing outside the litter box? Is something seriously wrong? And how can you stop this behavior? Well, here’s everything you’ll want to know and consider.

So, why is my cat peeing in the house all of a sudden? When cats begin peeing in the house suddenly, it’s usually because of a medical problem, although it could be because there’s something wrong with their litter tray or they’re suffering from stress or anxiety.

So it could be a number of things going on here.

But the underlying tone here is that something is wrong.

Perhaps with your cat. Possibly with their environment.

Nevertheless, let’s delve deeper into the reasons so that you can try and work out why your cat may be doing it.

Then we will be turning to how you should respond and, hopefully, get your cat to stop doing it!

So keep reading. It could save you a lot of time, effort, and money cleaning.

Oh, and save a piece of furniture or too in the process!

Reasons Why Cats May Pee In The House All Of A Sudden

The most common reason cats pee in the house all of a sudden is because of a medical issue. Other reasons include problems with their litter trays. Some cats pee in the house suddenly because they are anxious or stressed.

A Medical Problem

If your cat is suddenly peeing in your house, it’s always best to call your vet first to rule out any medical problems.

Your vet can carry out simple blood and urine tests to see if there are physical issues.

Anything that causes your cat discomfort can cause them to pee in the house. Several medical issues can be responsible for this.

Urinary Tract Infection (UTI)

When bacteria enter your cat’s urine, it can affect its bladder or kidneys, causing inflammation.

Your cat can find it difficult to urinate or only be able to urinate small amounts at one time. You might even find blood in your cat’s urine.

Crystalluria (Urinary Crystals in the Urine)

If your cat’s urine becomes too alkaline or too acidic in pH, crystals can form, causing inflammation in the bladder wall.

This type of inflammation can lead to the overgrowth of bacteria to cause a UTI, bladder stones, or both.

Cystic Calculi (Bladder Stones)

Stones in your cat’s bladder can cause the bladder wall to become inflamed, meaning your cat can feel like they’re desperate to pee (since the stones roll around inside).

Cats with bladder stones have a higher risk of contracting a UTI or another bacterial infection.

In severe cases, bladder stones can cause the urinary tract to become blocked, which requires urgent medical treatment to remove the stones surgically.


If your cat’s joints are causing pain, they can find it challenging to get to where they need to go to pee: either outside or in their litter box.

Your cat may (understandably) want to go for what’s easy to relieve themselves.

Kidney Disease

Kidney disease is usually seen in older cats, although younger cats can get it, too. Common signs of kidney disease include:

  • Decreased appetites (or becoming a picky eater)
  • Vomiting
  • Weight loss
  • Urinating more frequently
  • Drinking more than usual

Hyperthyroidism (Overactive Thyroid Gland)

Cats can be more prone to hyperthyroidism as they age, but it isn’t necessarily restricted to older cats.

Hyperthyroidism can cause your cat to:

  • Vomit (chronically)
  • Drink more than usual
  • Urinate more often
  • Lose weight (or even muscle mass)
  • Vocalize more than usual

Problems with Anxiety or Stress

Cats don’t like changes in their surroundings – they thrive on routine and stability.

Any change can affect your cat significantly, such as:

  • Moving their litter box to a different place
  • The absence of a family member
  • The introduction of a new family member
  • Disruption to the home (such as decorating, construction going on outside, etc.)
  • Having to compete for resources with other animals in the home (food, toys, space, scratching posts, window seats, etc.)
  • Encountering other animals outside (even if it’s just through the window)

Some cats can become so stressed that they develop Feline Idiopathic Cystitis (FIC).

The urinary tract is your cat’s stress organ – a stressed cat will often urinate in unusual places and in small amounts with more frequency.

Stressed cats can even get blood in their urine.

Litter Box Problems

Another reason your cat may be peeing in the house is because of problems with the litter box – it’s either dirty, inaccessible, or doesn’t have the right cat litter.

The Litter Box is Dirty

Cats are fastidious creatures with a powerful sense of smell, and much like us, they don’t like using an unclean toilet.

Litter boxes must be cleaned at least once a day, and definitely after every poop.

The litter needs to be refreshed with a deep cleaning of the tray every one to two weeks, rinsing away any residue of cleaning products.

A litter tray might smell clean but remember: your cat has a much more powerful sense of smell.

Light smells to us can be overwhelming to them: they can smell a drop of blood in an Olympic-sized swimming pool, so imagine what they can smell in a dirty litter tray!

Note: Be sure you are using cleaning products that are safe for use around cats.

The Litter Box Is Not In A Good Location

Sometimes your cat’s litter box is somewhere that causes him an extra effort to reach.

A cat with joint problems is unlikely to want to climb to reach his litter tray, step over a high side, or go up or down stairs to pee.

Cats also prefer to pee in safe, private locations, away from their food, water, sleeping areas, or toys.

Be sure the litter box isn’t near anything noisy like a washing machine.

The Litter Box Has the Wrong Kind of Litter

Some cats prefer sandy or clay-based cat litter, while others like crystals or wood pellets.

Kittens usually learn about cat litter by observing their mothers, forming their litter preferences as young as 3 weeks old.

It could be your cat wants the same litter they had as a kitten.

You can set up boxes (cardboard, if you like) with a different litter in each one to see what your cat prefers.

Make sure the litter is at least 6 cm deep because cats need to be able to dig.

Read more: Best Pellet Cat Litter [Top Picks & Buyers Guide]

Note: Avoid clumping cat litter, as it is more likely to stick to a cat’s paws and be ingested while self-grooming. Scented cat litter is also a no-no – it may smell appealing to us, but odors like lavender, citrus, or cinnamon can actually repel cats. Unscented litter is best for their sensitive noses.

You Have The Wrong Type of Litter Box

If you’ve changed your cat’s litter box recently, it could be the new one is:

  • The wrong size. The litter tray needs to be at least 1.5 times the length of your cat so they have room to dig, turn around, and squat. Many commercial litter trays are actually too small! You can make your own, though, using plastic storage containers.
  • The wrong type. Older cats may find it difficult to climb into a litter tray with high sides, so they would do better with open, uncovered trays. Some cats prefer covered trays as they feel safer, whereas other cats find covered trays intimidating because they can’t escape quickly.

This is the cat litter box I personally use and recommend.

Problems With Other Pets In The House

Sometimes one cat can bully other cats to the point where they don’t allow them access to the litter tray (or even the cat flap to go pee outside).

If you have several cats and they use litter trays, have one tray per cat, with each tray being placed in a different room.

Covered trays are best avoided if you have multiple cats because some timid cats want to be able to see if other cats are around.

The more you can give each cat its own toys, food and water bowls, litter tray, and space to sleep, the better (for most cats).

How Do I Stop My Cat from Peeing In The House?

The methods you choose to stop your cat from peeing in the house depend on the cause of the problem and your cat’s individual circumstances.

For a Medical Issue

If your cat has a medical issue, the priority will be to address that first:

  • UTIs and other infections or inflammations. Once your vet knows the type of bacteria that’s causing the infection, they’ll be able to prescribe the right antibiotics and other treatments to help your cat recover.
  • Crystalluria. In addition to the treatment prescribed by your vet, you’ll need to make sure to give your cat more water (perhaps using a cat fountain, as these tend to encourage cats to drink more). Your vet will also recommend an appropriate “dissolution diet” that can help slow the formation of – or even dissolve – some of the crystals.
  • Bladder Stones. If your cat has bladder stones, your vet will decide whether a prescription diet is enough to dissolve the stones. In some cases, surgery is required before the stones can block the urinary tract (with possibly fatal consequences).
  • Arthritis. Cats who suffer from arthritis can often experience improved quality of life with pain medication and/or cat joint supplements, so discuss these options with your vet. If neither of these is possible for your cat, you may have to put an easily-accessible litter box where your cat likes to hang out (but not by her food; see above).
  • Kidney Disease. If your cat has kidney disease, this is a chronic condition, although the progress of the disease can be slowed down with kidney supplements, antioxidants, diet changes, and possibly fluid therapy given at home. Discuss your options with your vet.
  • Hyperthyroidism. Your vet will diagnose this condition through blood tests, and they’ll help you get the right medication to give to your cat to help them lessen the symptoms and manage the condition.

For Anxiety or Stress

Dealing With the Source of the Stress

For an anxious or stressed cat, the quickest and most obvious solution is to remove the source of the stress, although this is not always possible.

Often you will have to find other ways of calming your cat (see below).

For example, if you have two cats in your household and one of them is taken ill, the other one might start peeing in the house because they’re concerned about their friend.

This happened to someone I know – one cat had had a hip problem and had to rest inside a large cage so that they weren’t tempted to walk and hurt themselves.

His brother was so worried about his littermate that he started peeing in the house.

It was only once he was allowed time inside the cage with his brother that he calmed down and, although he still wasn’t happy with the situation, he stopped peeing in the house.

For Feline Idiopathic Cystitis (FIC)

If your cat has developed FIC out of stress, you’ll need to apply medical treatment as recommended by your vet to help heal your cat’s bladder problems (see UTIs, above).

At home, do what you can to calm your cat. You can try pheromone sprays (make sure these are for cats) as well as behavior modification medications (if your vet feels they are necessary).

Ways To Calm Your Cat

In addition to pheromone sprays or behavior modification medications, you can also try the following to help calm your cat:

  • Make sure your cat has their own resources (litter tray, food bowl, toys, etc.) if they’ve been previously competing with other animals.
  • Give your cat lots of love and attention (on their terms, of course).
  • Try soothing music for your cat – there are specialized YouTube channels, for instance, which offer tailored music that cats love to help them relax.
  • Establish a secure routine for your cat so they always know what to expect (especially around mealtimes and playtimes).

Other Things To Know About Your Cat Peeing In the House

You’ll need to thoroughly clean the area where your cat has peed so that they don’t go back to the same place and form a habit of peeing there.

Cats Will Pee In The Same Spot

Cats will usually pee in the same spot, whether it’s indoors or outdoors, since they use peeing to mark their territory.

If your cat has peed inside, you need to clean the mess effectively so that they don’t go back there and do it again.

Some cats prefer certain types of substrates – carpet, wooden flooring, etc.

Restrict your cat’s access to the type of substrate they prefer while you’re dealing with elimination problems.

You can also try putting a litter tray in the exact spot where your cat has peed inappropriately to make the most of their love of routine.

If your cat uses the tray there, leave it in that spot for at least one week.

Then you can slowly move it inch by inch back to where you want it, making sure your cat still pees in it each time.

Some people have had success by turning the spot into an area with a different purpose – a feeding, sleeping, or playing area, for instance.

How To Effectively Clean Cat Pee

Homemade Remedies

You can get rid of the smell of cat pee using baking soda and vinegar.

Vinegar may be smelly, but as an acid, it neutralizes the alkaline salts that form with dried pee stains.

Here’s how to do it on carpets:

  1. Get an old towel or rag to soak up as much cat pee as possible. When you’re done, throw the towel away (outside).
  2. Sprinkle liberally baking soda over the whole area.
  3. Let the baking soda sit for ten minutes.
  4. Pour some vinegar over the baking soda and let it fizz for a few seconds.
  5. Using a fresh rag or towel, blot the entire area.

For walls and floors, make a vinegar solution with one part water and one part vinegar.

Note: Make sure you avoid bleach or ammonia-based cleaners, as these can tempt your cat to go back to the same spot even more!

Odor Neutralizers

You could try odor neutralizers, which are effective for removing the urine smell (and lessening your cat’s interest in peeing there again).

If you do use odor neutralizers, make sure the ones you choose are safe for use around cats.

Cats mark places by rubbing themselves against them with their cheeks or anus, which contain scent glands.

If a visiting cat has been in your home and has marked certain spots, your cat may pee there to cover the visitor’s scent with their own.

Do your best to eliminate any traces of scent from the visitor to avoid this problem.


A cat peeing in the house suddenly indicates that something has gone awry.

How severely, or whether it’s something that requires veterinary support, is subject to context though.

Not every cat who begins to do this has developed a medical issue, though it is plausible, and you likely cannot rule it out without further investigation.

Unless something has abruptly changed, like you have started to use a new litter box, changed the location, changed the litter or introduced a new pet to your home.

Otherwise, if you can rule out any significant environmental changes, then I would personally suggest you contact a vet.

Get your cat checked over. Just to be sure.   

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