empty clean litterbox

Cat Not Using Litter Box All Of A Sudden? Why & What To Do About It

As a cat owner, there is nothing worse than your cat not using their litter box.

Unfortunately, it is also a common issue; cats are notoriously finicky creatures and there are many reasons why they have stopped using their litter box, from something as simple as a dirty litter tray to more serious illnesses.

Reasons Cats Won’t Use Their Litter Box:

Below are the primary reasons why a cat may not use their litter box all of a sudden and what you can do to fix the problem.

1. They Don’t Like Their Litter Box

The most common reason that your cat isn’t going to the bathroom in their litter box all of a sudden is because something small has changed which they have decided they don’t like. 

Some examples of what could be putting your cat off include:

  • Incorrect Amount of Cat Litter: If there is too much or too little litter in their litter box, your cat may decide they prefer to go to the toilet elsewhere as they can’t effectively dig and cover up their excrement.
  • Too Small: Your cat’s litter box may also be too small, meaning it can be uncomfortable for your cat to use and that there isn’t enough space for them to find a clean spot and do their business. As a rule of thumb, the litter box should be 1.5x the length of your cat.
  • Wrong Location: Your litter box may also be in the wrong location and not offer your cat enough privacy or escape routes.
  • Wrong Style: From regular litter trays to top entry litter boxes and hooded designs, there is a range of different litter boxes available on the market, and the issue could be that your cat doesn’t like the one you’ve gone for.

If your cat is not using their litter box all of a sudden, think if you have changed any of the above factors.

Have you recently changed your cat’s litter box to a new one? Have you changed the amount of litter you put in it? Have you moved the location of the litter box in your home?

If so, try switching back to the old litter box and seeing if this helps. 

2. They Don’t Like Their Cat Litter

If you have recently changed the type of litter you use, this could also deter your cat from using their litter box.

three different cat litter types side by side

There is a range of different cat litters to choose from, including:

  • Clay Clumping Litter
  • Pine Litter
  • Silicone Crystal Litter
  • Recycled Paper Litter

Each of these cat litters are made from a different material and have different textures and smells. If your cat is not using their litter box all of a sudden and you have recently changed the types of litter you use, that could be why!

Also, even if you kept the type of cat litter the same but changed the brand, such as switching from one brand of clay clumping litter to a new one, it will have a slightly different formula that your cat may turn their nose up at.

3. Their Litter Box is Dirty

Cats have an extremely good sense of smell with 40x more odour-sensitive cells in their noses than humans, and they are exceedingly clean creatures. 

Therefore, it follows that cats are particularly sensitive to bad smells, and if their litter box is dirty, they will be deterred from using it.

In fact, this is the most common reason why cats suddenly stop using their litter tray. Have you stopped cleaning your litter box as regularly as you used to?

As a minimum, you should be sure to scoop up any clumps of litter or faeces from the litter box once per day and empty, clean, and refill the litter box at least once per week. 

This will ensure the litter box is clean enough at all times for your cat to be happy using it.

4. They Are Sharing a Litter Box

Have you recently got a new pet? If you have assumed they will be happy using the same litter box, think again! 

Another reason why your cat is not using their litter box all of a sudden is that they’re sharing it with another cat.

For one, shared litter boxes will get dirtier a lot quicker than litter boxes that are being used by a singular cat, which will deter your cat from going in their tray.

cats may become territorial about their litter box if a new cat is introduced

Additionally, your cats will be able to smell each other’s presence in the litter box. Cats are independent creatures and love to have their own space, and this means their own toilet each.

As a minimum, you should have at least one litter box for every cat you have. 

However, if you have space, 1.5 litter boxes per cat is better – for example, three litter boxes for two cats – as this provides plenty of options for them to go.

5. They Are Stressed & Anxious

Cats are very sensitive to the world around them and love their everyday comforts and routine. 

If something in their environment or routine has changed, it could be acting as a stressor and the reason why your cat has stopped using their litter box all of a sudden.

Possible causes of stress could be:

  • Moving house
  • New guests, a new baby, or pets in the home
  • Unfamiliar cats intruding into the home
  • Competition for resources in a multi-cat household
  • Changes to your usual routine

If your cat is suffering from stress or anxiety, you will likely notice other symptoms alongside their reluctance in using their little tray. This includes diarrhoea and vomiting, loss of appetite, increased tiredness, or poor coat condition.

There may also be other behavioural changes too, such an excessive meowing, spraying urine on the furniture, excessively scratching, or acting aggressively towards you or your guests.

6. They Have a Urinary Tract Infection

Another reason why your cat is not using their litter box all of a sudden could be because they have a urinary tract infection (UTI), which causes painful and frequent urination.

You should be able to tell if your cat has developed a UTI as they will frequently refuse to use their litter box but will only ever urinate small amounts, as well as other symptoms such as crying for pain when passing urine or a strong ammonia smell in their urine.

UTIs can be caused by a range of different things, including the accumulation of debris in the bladder or urethra, bladder infection or inflammation, injury to the urinary tract, or even stress. Hyperthyroidism and diabetes mellitus may also act as risk factors.

You will need to take your cat to the vet so that the UTI can be diagnosed as there is a huge range of causes and conditions.

Your vet may recommend antibiotics to fight the infection, dietary changes, or potential surgery if a urinary blockage needs to be removed.

7. They Are Incontinent

If you have an elderly cat that is not using their litter box all of a sudden, it could be that they have become incontinent with old age, so they may leak urine or faeces involuntarily.

Incontinence could be caused by cognitive impairment and they may simply have forgotten where their litter tray is, but also that your cat has aged it has lost control over their urinary muscles and cannot hold their urine and faeces in.

old cat on bed

Caring for an incontinent cat is difficult and can be frustrating, but switching to a shallower litter tray and providing multiple around the home could be all it takes to make their accidents less frequent. 

Your vet may also be able to offer muscle stimulants or specific dietary changes to help with the condition.

How to Help Your Cat Use Their Litter Box

If your cat is not using their litter box all of a sudden, there are some simple changes you can make to diminish this bad behaviour:

  • Ensure that their litter box is large enough for them to use comfortably
  • Ensure that if you have multiple cats, each cat has its own litter box as a minimum
  • Ensure you put 1-2 inches of cat litter in the base of the tray
  • Keep the litter box clean by scooping daily and cleaning weekly
  • Ensure your litter box is in a quiet yet easily accessible location with lots of escape routes
  • Go back to using your old litter tray or old cat litter if these have recently been changed
  • Take your cat to the vet so they can check for any urinary symptoms or other medical causes
  • Clean any accidents outside their litter box with an enzymatic cleaner to neutralise odours
  • Make any places they commonly go outside of their litter tray less appealing, such as placing double-sided sticky tape in the area

Regardless of why your cat is not using their litter tray all of a sudden, if you ensure you do all of the things on the list above, they should start using their litter box again in no time at all. 

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