Behaviour Changes In Cats and What They Mean

Changes in behaviour can be the first clue that there is something wrong with your cat. Cats are hardwired to hide signs of sickness but do provide subtle clues.

Cats should visit their veterinarian at least once a year for a health check-up, and cats over seven years of age should have bi-annual visits. A year is a long time in the life of a cat, who lives on average 12-15 years and annual health checks are important, even if your cat is otherwise healthy. Not only will your cat have his health evaluated, but it gives you and your veterinarian a chance to talk about your cat’s health in general including parasite control, vaccinations, nutrition and your cat’s changing needs as he ages.

Sleeping more

Most healthy adult cats sleep between 16-18 hours a day, which is more than twice that of their human caregivers. Kittens and seniors sleep more. However, most cats have periods of wakefulness during the day, and we should be aware of what is normal sleeping and what is excessive.

I find my cats are most active in the mornings and am greeted with hungry cats and complaints when I get up. After breakfast, they like to cause chaos, before spending most of the day snoozing on and off. They have a second period of activity in the evening, and I find that is when they actively seek out attention. NO doubt because they have a captive human audience who are relaxing.

Sleeping more can be quite subtle, but it is good practice to know your own cat’s routine, so if it does change, you will notice.

Meowing all the time

Some cats are naturally talkative; Siamese cats are famed for their chattiness. We are not talking about a cat who has always been on the vocal side. A usually quiet cat who becomes vocal can be a sign of an underlying problem. Some causes include:

  • An entire female cat in estrus
  • A cat crying in the litter tray can be experiencing pain, or an inability to urinate, this is more common in male cats who have a narrower urethra
  • Senior cats who cry for no apparent reason may have dementia
  • Grief, due to the loss of a family member or pet
  • Systemic diseases including hyperthyroidism and chronic kidney disease which are seen most often in middle-aged to senior cats
  • Pain which may be due to trauma, arthritis, cancer or other internal diseases
  • Anxiety, which has many causes including
  • Declining eyesight or vision

Urinating or defecating outside the litter tray

This is a common source of frustration for cat owners. Cats are fastidiously clean, and if they refuse to use the litter tray, there is always a reason why.

Sudden changes in litter tray habits always warrant medical investigation. The most common causes of inappropriate urination or defecation are:

Other signs to watch for include frequent genital licking, obvious signs of discomfort in the litter tray, passing small amounts of urine and blood in the urine. A blocked cat is a medical emergency, due to the build-up of toxins in the cat’s blood.

Aggressive behaviour

A normally happy and loving cat who suddenly displays aggressive behaviour is a definite sign something is wrong. Pain is the most common cause of sudden aggression in cats. In the absence of a known traumatic injury, pain may be due to arthritis, particularly in older cats, or something going on inside which may include:

Change in grooming habits

Cats are fastidiously clean animals who devote a large portion of their waking hours to grooming. Changes can either be a decline in grooming or in some case, increased grooming.

Grooming less:

  • Pain, especially arthritis in older cats
  • Dental problems
  • Obesity

Grooming more:

  • Hyperthyroidism
  • Parasites
  • Allergies
  • Psychogenic


Sick and injured animals are vulnerable to predatory animals, and it is natural for them to hide to reduce their chances of becoming the next meal to another animal. They will seek out dark, quiet and out of the way areas such as a wardrobe or under the bed.

Loss of interest

Has your cat suddenly stopped helping you around the house with household chores? Is he no longer waiting for you at the door when you come home from work? Is he no longer interested in playing or having cuddles? All of these subtle clues can be due to an underlying medical problem or depression.

Changes in activity

A sudden increase or decrease in activity can have an underlying medical problem. Most cats slow down as they age, but normal age-related changes happen slowly.

Decreased activity:

  • Pain
  • Arthritis
  • Pancreatitis
  • Heart disease
  • Dementia

Increased activity:



The veterinarian will perform a physical examination from you and obtain a medical history. Baseline tests including complete blood count, biochemical profile and urinalysis will be taken, which can show any possible abnormalities.

Depending on the results of baseline tests, along with your veterinarian’s index of suspicion, additional tests may be necessary.

Most of the diseases can be managed, if not treated, however, the earlier your cat is treated, the better the outcome.


  • 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

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