Cat Behavior Changes That Might Mean Something's Wrong

Atypical Behaviors Can Also Be Perfectly Normal

Brown striped cat laying down with partially open eyes

The Spruce / Adrienne Legault

When a cat's normal behavior changes subtly or dramatically, a conscientious owner can't help but feel concerned. Knowing what is "normal" for your cat will make it easier to recognize behavioral problems that arise. Some changes can indicate underlying health or social issues, while others are simply personality quirks that arise as your cat grows older. Learn the difference for both your cat's well-being and your peace of mind.

Aggressive Behavior Changes

Some cats have a stronger prey drive and will act out aggressively towards toys, children, other pets, or even their owners. This aggressive behavior is natural, but if a normally mellow cat suddenly starts acting aggressively, then this is a cause for concern.

Pain and fear are often the reasons for a cat to exhibit unprecedented—or unprovoked—aggression. Events that can cause a cat to be fearful include:

  • Negative veterinary or boarding facility visits
  • New animals in the household (or visible outside)
  • Negative encounters with people
  • New smells on you or your cat's belongings.
  • Pain from recent surgery, trauma, infection, or illness

Resolving the aggressive behavior may mean finding and eliminating the cause of the pain or fear, using medications and behavior supplements, and reassuring your cat. Discipline is not the solution for aggressive behavior in cats.

Brown striped cat biting hand aggressively

The Spruce / Adrienne Legault

Eating Behavior Changes

Cats are creatures of habit. They will quickly learn when it's meal time if you meal feed or that there is always food available if you elect to leave a bowl out. If your cat's speed of eating or the amount of food consumed changes drastically, then it may signal a problem such as:

  • Hyperthyroidism will increase a cat's appetite and the amount of food consumed without weight gain
  • Dental disease, illness, or stress may decrease a cat's appetite
  • A change of food may not appeal to your cat
  • Hairballs can make a cat feel nauseated, bloated, and uninterested in food

Playing Behavior Changes

Some cats are naturally more playful than others and, just like people, they have individual personalities. But when a regularly playful cat doesn't want to play like it used to, it may be cause for concern. A cat that doesn't feel well or is in pain may not want to jump around and chase toys. A veterinary visit may be in order if your cat does not return to a normal playful cat after a couple of days.

Brown striped cat playing with wired toy in front of black cat

The Spruce / Adrienne Legault

Hiding Behavior Changes

Cats that do not feel well or are scared are likely to hide, Stressful or traumatic events may also precipitate hiding, including:

  • Veterinary visits
  • Strangers or guests in the house
  • Family schedule changes

If the hiding is due to an event, then your cat should return to normal after a few days, If it is due to an illness or pain, the cat may need to be examined by a veterinarian.

Black cat with yellow eyes hiding underneath furniture

The Spruce / Adrienne Legault

Elimination Behavior Changes

One of the main reasons cats are relinquished, euthanized, or abandoned is the development of a urinary or fecal elimination problem. Behavior changes in the urination and defecation habits of your cat are most often related to stress, fear, or a lack of appropriate, clean, litter box options.

Some cats suddenly choose to defecate and/or urinate outside of their box, and this behavior is your cat trying to tell you something. They may not like the size of the box, the kind of litter, how dirty the litter is, the placement of the box, or the number of litter box options they have.

In some cases, cats may be trying to tell you that they don't feel well and that they have a urinary tract infection or pain from a digestive tract problem. If you notice abnormally large clumps of litter from urine, spots of blood in the litter box, absent or very small clumps of litter from urine, or your cat is straining, crying, or eliminating outside of the litter box, you should not hesitate to visit the veterinarian to address the potentially life-threatening infection.

Many other things can cause elimination behavior changes and even the experts do not fully understand all the reasons behind them. Medical reasons for elimination behavior changes should always be ruled out prior to fixing any environmental issues.

Scratching Behavior Changes

Scratching is a normal cat behavior, but if your cat suddenly starts scratching more, especially in one particular spot, it could be an indication that it is stressed. Nutritional supplements designed to relax your cat without sedating it, as well as pheromones, may help lower your cat's stress level.

Otherwise, think about any changes in the environment that may have negatively impacted your cat and do your best to correct them.

Brown striped cat scratching ear on patterned rug

The Spruce / Adrienne Legault

Sleeping Behavior Changes

Cats who are not feeling well may sleep more than usual. There is, of course, the simple possibility that your cat is just lazy and/or overweight, but if a cat starts sleeping more than it used to, you should schedule a visit to your veterinarian.

Brown striped cat sleeping on mint green-covered bed and tan pillows

The Spruce / Adrienne Legault

Grooming Behavior Changes

Grooming is a natural cat activity. They typically groom themselves and others when they are relaxed or feel as though their fur is messy. Cats that stop grooming or have a major decrease in self-grooming may be ill and should be checked out by a veterinarian.

Sometimes cats who are gaining weight are unable to reach certain areas of their body, therefore they are unable to groom themselves. This can be fixed by helping your cat to lose the extra weight with less food or a lower calorie diet.

Sore joints and muscles are also a contributing factor in grooming. Cats that have osteoarthritis or injuries may not be able to reach certain areas to groom that they were once able to reach.

Brown striped cat rubbing its head while grooming

The Spruce / Adrienne Legault

Vocalization Behavior Changes

Cats have many vocalizations and reasons for making them. Possibilities include:

  • Crying and yowling as indications of distress, confusion, fear, or pain
  • Night vocalizing (meowing or yowling), which may be due to cognitive dysfunction
  • Hissing or growling (indicators of pain or fear)

Assess the situation and think about what changes could be causing the vocalizations. If you cannot think of any reasons for the sudden noises your cat is making, consider scheduling a visit with your veterinarian to see if there is a medical reason causing distress in your cat.

When Is Cat Behavior an Emergency?

Any change in a cat's behavior could be considered an emergency, so if you're unsure, promptly schedule a vet visit. Sudden reclusive behavior, lethargy, or aggression are possible indicators of pain or illness that should be diagnosed and treated as soon as possible.

Minor changes in behavior, or those that appear and pass quickly, are rarely cause for concern and can be chalked up to cat "quirks."

Article Sources
The Spruce Pets uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Feline Behavior Problems: Aggression. Cornell Feline Health Center.

  2. Hyperthyroidism in Cats. Cornell Feline Health Center.

  3. Feline Inappropriate Elimination: How to Get Owners to Treat, Not Euthanize. VetFolio/North American Veterinary Community.

  4. Feline Behavior Problems: House Soiling. Cornell Feline Health Center.

  5. Cognitive Dysfunction. Cornell Feline Health Center.