Changes in Litter Box Habits – What Do They Mean?

The litter tray can be a source of frustration for both cats and cat lovers when a cat suddenly starts going to the toilet outside the tray. There can be several reasons for a cat to abruptly stop using its litter tray which can be loosely divided into behavioural or medical.

The first thing to take the cat to a veterinarian to evaluate its health. Several medical problems can be a reason why the cat is suddenly going to the toilet elsewhere. This can be because the cat starts to associate the litter tray with pain, or fecal/urinary incontinence.

Questions to ask

  • Has anything changed in the home? A new family member or pet?
  • Does the urine or feces appear normal? Is there blood, mucus, diarrhea, a strong odour?
  • Have you noticed any behavioural or medical changes? Loss of appetite, frequent genital licking, hiding?
  • Is the cat getting along with all other pets in the home?
  • Have you made any changes to litter trays? Taken one away, changed cat litter or location of the tray?
  • How has the weather been lately? If your cat goes to the toilet outside, has it been raining a lot, or especially cold?
  • Does the cat have any underlying medical conditions?


Cystitis is the inflammation and/or infection of the bladder and a common cause of lower urinary tract disease in cats. It can be caused by infection, bladder stones, diabetes, holding on for too long, dehydration, which concentrates the urine and long-term steroid use. There is a higher incidence of cystitis in female cats.


  • Straining to urinate
  • Crying in the litter tray
  • Blood in the urine
  • Urinating outside the litter tray
  • Smelly urine


The goal of treatment is to find and address the underlying cause and manage symptoms. This can include antibiotics to treat bacterial infection, increase fluids to dilute the urine, dietary changes to diet to keep the urine pH below 6.5 and multimodal environmental modification (MEMO), such as switching to unscented cat litter, providing places to hide, enriching the environment and switching to a wet diet to increase fluid intake.


Constipation is the infrequent passage of hard and dry stools. There is no set number of bowel movements a cat must take in a day, but one to two is average. Constipation can affect cats of any age, although it is seen more commonly in middle-aged to elderly cats.

Chronic constipation can lead to a condition known as megacolon, in which the colon becomes abnormally dilated and enlarged and loses its ability to contract. This may ultimately lead to obstipation, which is a complete blockage.

Causes of constipation include dehydration, which leads to dry, firm stools which are difficult to pass, reluctance to defecate due to pain, obstruction, certain drugs, neurological damage to the nerves in the colon and anus, narrowing of the pelvic canal which may be congenital or due to trauma, low blood potassium levels and idiopathic (no known cause).


  • Defecating outside the litter box
  • Straining in the litter tray
  • Crying in the litter tray
  • Abdominal pain
  • Depression
  • Loss of appetite
  • Genital licking
  • Depression
  • Hunched over appearance


Treat the underlying cause where possible.

Mild cases of constipation in cats can be treated at home by adding fibre to the diet. This may include boiled pumpkin or products such as Metamucil (psyllium). Increase water by switching to a wet diet and if recommended, laxatives.

Severely constipated cats will need an enema to unblock the colon and fluids to correct dehydration.


Diarrhea is an intestinal disturbance characterised by the rapid movement of abnormally loose or watery stools (feces). It is not a disease in itself, but a symptom of an underlying disease or disorder.

Diarrhea can affect the small intestine, the large intestine or both. It may be acute (sudden onset), chronic (over a long period) or intermittent (come and go). There may be an increase in the number of bowel movements, an increased amount of feces or watery feces.

There are many causes of diarrhea including dietary allergies or intolerances, dietary indiscretion, a sudden change in diet, bacterial, viral, protozoal or fungal infection, gastrointestinal worms, certain medications, poisoning, systemic diseases such as hyperthyroidism, liver disease or kidney disease and cancer.


Small intestine diarrhea: Volume is increased, frequency 2-3 times normal, no mucus, urgency may be normal to mildly increased. Cats with chronic small intestinal diarrhea lose weight and body condition as they are not absorbing nutrients.

Large intestine diarrhea: Volume is normal to decreased, mucus and blood may be present, the urgency is increased, and frequency is more than 5 times normal.

  • Defecating outside the litter box
  • Feces may also be yellow and frothy in appearance, be mixed with blood (dysentery) and/or mucus.
  • Loss of appetite
  • Dehydration
  • Increased thirst, due to fluid loss
  • Flatulence (farting)
  • Abdominal pain
  • Lethargy
  • Blood, fat or mucus in the stool
  • Weight loss
  • Increased urgency to defecate


A bland diet to rest the gastrointestinal tract, supportive care such as fluids and nutritional support and specific treatment depending on the underlying cause.


Feline lower urinary tract disease is a group of conditions affecting the cat’s lower urinary system and bladder, including urolithiasis (stones in the urinary tract), cystitis (inflammation of the bladder), urinary tract infection and urethral obstruction.


  • Urinating outside the litter box
  • Straining to urinate
  • Blood in the urine (hematuria)
  • Frequent visits to the litter tray
  • Excessive genital licking
  • Crying when urinating


A completely blocked cat will need to have his bladder emptied, fluid therapy, stone dissolving diets, antibiotics, and encourage water consumption to dilute the urine.

Bladder stones:

Also known as uroliths or calculi, bladder stones are rock-like deposits in the urinary bladder. The cause of bladder stones is concentrations of certain minerals in the urine. The most common types are struvite and calcium oxalate. Other less common bladder stones include ammonium urate, calcium-ammonium-phosphate, urate, cystine and compound (stones that contain different materials).


  • Urinating outside the litter box
  • Frequent urination which often produces only a few drops
  • Difficulty urinating (dysuria)
  • Crying in the litter tray
  • Blood in the urine (hematuria)
  • Genital licking



Antibiotics if a bladder infection is present, stone dissolving prescription diets, urinary acidifiers and increase water consumption to dilute the urine.


Surgical removal of the stones is 100% successful and has the advantage of confirming the type of stone involved. There are risks with any form of surgery, and there is recovery time. However, surgery is the only option if a diet fails to dissolve the stones or if they are the type of stones that diet alone can’t treat.

Bladder cancer:

There are several types of tumour to affect the bladder (and urethra), with the most common being transitional cell carcinoma (TCC). Other types of bladder tumour include benign mesenchymal tumours, squamous cell carcinoma, rhabdomyosarcoma, and lymphoma.

The exact etiology is unknown, in humans, bladder cancer is higher in people working in chemical industries, and it is speculated that chemicals used to treat fleas and ticks in cats (and dogs) may increase the risk of cancer, along with environmental pollutants and insecticides. Obesity is another factor, the theory being that the fat stores these chemicals, which are slowly excreted in the urine.



The treatment of choice is surgery to remove the tumour if it is in a favourable location.

Laser therapy to remove or debulk (reduce the size of) the tumour.

The nonsteroidal anti-inflammatory drug piroxicam (Feldene), has been shown to shrink and/or inhibit the growth of bladder tumours.

Behavioural causes:

Once the veterinarian has ruled out a medical cause, it is important to figure out why the cat is reluctant to use the litter tray. Common issues include:

Dirty litter trays:

Cats are fastidiously clean by nature, and that extends to their toilet. If a litter tray is dirty, a cat will find somewhere else to go to the toilet. There should be one tray per cat, plus one extra. So, a home with two cats should have three litter trays.

Scoop out solids twice a day. Once a week, disinfect with a 1:30 bleach solution (use warm water, not hot), rinse thoroughly (to remove poisonous chemicals and the smell of bleach), replace with clean litter. I always like to mop the floor under and around the litter trays too.

Unsuitable litter trays and litter:

Trays should be large enough to accommodate the cat. A small tray for kittens to climb into and out of, and a large one for adults.

Cats have different preferences, and it can take some time to find the right tray for your household. Some cats like covered trays; others don’t like to be closed in and prefer open litter trays.

When you bring a new cat into the home, if possible, stick with the cat litter they are used to and slowly switch to your preferred type once the cat has settled in. Do this over several days by mixing the new litter in with the old.

Avoid litter with a strong scent and don’t use any products on or in the tray with a strong odour. What may smell nice to us can be overpowering to a cat.

Litter box location:

Cats like privacy, but they don’t want to have to climb two flights of stairs to go to the toilet. If you live in a multi-story home, there should be at least one litter tray on each floor, more for multi-cat homes.

Place the litter tray in a quiet area, not directly next to food and water bowls, but within the same proximity.

Don’t line litter trays up next to each other, scatter them around the house, and as already mentioned, place a litter tray on every level of the home.

Inter-cat issues:

If there are cats who don’t get along, one cat (usually the less-dominant one) may resort to going to the toilet in other places to avoid being ambushed by the dominant cat.

How to clean cat urine:

Don’t physically punish a cat who has gone to the toilet outside the litter tray, I know it is frustrating, but the cat isn’t doing this to annoy you and won’t understand why you are yelling, hitting or rubbing his nose in it. All this achieves is to make the cat fearful of you, and a stressed cat is even more likely to go to the toilet elsewhere.

The quicker you can clean up urine, the better. Adult cats urine contains a sulfur-containing amino acid known as felinine; the hormone testosterone stimulates the production of felinine once the cat reaches maturity. Males and females excrete this chemical; however, males excrete more, especially intact males. Felinine is odourless until bacteria begin to break it down, at which time it produces its characteristic pungent smell. Felinine is a precursor to pheromones which serve to attract members of the opposite sex and to mark the cat’s territory.

Cat urine can be cleaned with a commercial urine remover or a homemade one. White vinegar and bicarbonate of soda are the most commonly used ingredients used to clean cat urine. Avoid ammonia-based products as cat urine contains ammonia, and the use of an ammonia-based product can encourage a cat to re-visit the area.


  1. Remove as much of the urine as possible by blotting the stain or wet area with paper towels. Don’t rub the area as you will push the urine further into the carpet. If the stain has already dried, moisten with warm water before beginning the stain removal process.
  2. Lay additional paper towels over the stain and gently press to absorb as much of the moisture as possible. Repeat several times until you have removed most of the urine.
  3. Apply any stain and odour removal product.
  4. For best results, choose a bacterial/enzyme cleaner that will remove all parts of the urine stain as well as the odour.
  5. Rinse with warm water and dry.

We have a selection of cat urine odour removal recipes on this page.


  • Julia Wilson, 'Cat World' Founder

    Julia Wilson is the founder of Cat-World, and has researched and written over 1,000 articles about cats. She is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. Full author bio