Feline Aggression

Aggression is threatening or hostile behaviour, or behaviour that is intended to cause harm to a person, another cat, or animal. Aggression is not an uncommon behavioural problem seen by behaviourists. The causes can be complex in terms of triggers and targets, and the consequences can be significant. Cats can bite and inflict lacerations which can become infected, and in very rare cases cat scratch fever. Also, unfortunately, end with cats being surrendered to animal shelters. Working with aggression problems will take time and commitment, but many aggressive problems can be successfully resolved.

Understanding a cat’s body language during “normal” circumstances can help you identify when they are acting out of character. It enables cat parents to “read” their cats and understand their feelings and motivations for doing what they do. Knowing cat postures and what they mean can help owners deal with issues more effectively.

Signs of aggression (body language) include:

  • Ears flattened backwards
  • Tail held straight up with hairs raised
  • Direct stare
  • Piloerection (hackles up): including tail
  • Directly facing opponent, possibly moving towards them
  • An arched back
  • Growling, howling or yowling

Signs of Fear/ Defensive body language:

  • Head tucked in
  • Crouching
  • Tail curved around the body and tucked in
  • Ears flattened sideways or backwards, whiskers flattened to the face
  • Open mouth hissing or spitting
  • Eyes wide open
  • Piloerection (hackles up)
  • Cat may deliver quick strikes with front paws, claws out

Common types of Feline Aggression:

Cat to Human Aggression
Normally the root of human aggression is a result of the person. Cats, who as kittens were played with, or handled roughly by people. Another cause of human aggression is fear-induced or pain-induced aggression. If a cat is irritated, in pain or has certain medical conditions they may lash out at people to protect themselves. Cats with aggression problems should always be examined for underlying medical conditions, especially painful conditions such as arthritis, dental disease, and wounds/abscesses.
Play aggression

Young cats can be prone to playing vigorously, but when the play is directed toward people or becomes overly rambunctious, it can cause injury and damage to household items. Play aggression involves the cat approaching the target (stalking) and then leaping. There is usually no warning growl or hiss. It can also involve predatory behaviours such as, stalking, chasing, attacking, running, pouncing, leaping, swatting, fighting and biting.

Young cats as kittens who were not raised with littermates, or had a lack of opportunities to play, sometimes show play aggression. Cats learn with their littermates that if they are biting or scratching too hard, the other kittens stop playing or retaliate. Kittens raised on their own early on may not learn this.

Steps to help:

  • First, determine if there is a pattern to when and where the behaviour happens.
  • If there is a pattern, try to avoid trigger situations where possible. Try to pre-empt the aggression by distracting the cat with play or not allowing access to places that encourage the behaviour.
  • Do not encourage aggressive play. This means ignoring unwanted behaviour: not reinforcing it with attention if possible. 
  • Provide interesting toys and rotate them.
  • Teach bite and claw inhibition using positive reinforcement training. Do this when the cat is calm, not when motivated to play. Gently pat or play with your cat: don’t get them excited. As long as they stay gentle, let them nibble your hand. As soon as they put pressure on your skin, immediately stop playing and ignore them for some time. This will teach your cat to play gently. Just as a kitten would learn from another kitten. As time goes by, you reduce the amount of pressure that you tolerate. You can even teach your cat not to grab you with their mouth, and never to use their claws when they interact with you.
  • Rewarding a cat with a food treat for allowing brief light stroking without signs of aggression may also help.
  • Always supervise cats with children as they often miss the visual cues of impending aggression. Ideally, owners should prevent physical contact between children and a cat with a history of petting-induced aggression until this has been managed.
Patting Aggression
Many cats enjoy being stroked since it is like being groomed by their mothers, however, adult cats have a strong survival mechanism and they can feel vulnerable to attack if they allow themselves to become too relaxed and comfortable. They may develop a sense of conflict between pleasure and potential danger and this can result in a sudden aggressive gesture to escape from the situation.

For some reasons still unknown, some cats may suddenly become aggressive while being petted. Possible causes are overstimulation or an attempt by the cat to gain control when petting ends. Handling, bathing, grooming and nail trimming can also cause this type of aggression. Often the cat will have dilated pupils, tail lashing, and ears moved backwards on the head before becoming aggressive. Some cats don’t tolerate being petted for a long period. The cat tends to be content while being petted initially, then suddenly it attacks the person, jumps down, runs a short distance, sits, and grooms, with pupils, dilated.


  • Don’t pat the cat for a prolonged period of time.
  • Wait for the cat to initiate the patting, then keep it short.
  • Look for signals the cat does not wish to be petted anymore.
  • Desensitise the cat by petting them for short periods and increasingly longer times, while giving a food reward for tolerating being petted.
Fear Aggression

This may be seen when a cat encounters unfamiliar stimuli, such as a new person, animal, or noise, or even when exposed to an unpleasant event such as a trip to the vet. Cats usually display fear aggression when they feel threatened, especially when cornered.

Ears will generally be turned back, and the tail and body lowered. Teeth can show and there may be hissing.

The best way to deal with fear aggression is to identify and avoid fear situations that produce a fearful response. Then you can attempt gradual desensitisation by briefly exposing the cat to the fearful situation, then reward non-aggressive behaviour with food and praise.

  • Give the cat a food reward while they are calm during the stressful situation. Rewarding with a food treat while calm reinforces relaxation during exposure to the fearful situation.
  • It is important not to retreat or show fear, as this may reinforce the behaviour if your retreat is what the cat wants. Lack of attention is a better way to handle the aggression.
  • Sometimes medication can be used in combination with behavioural modification (speak to your vet).
  • Synthetic hormones can also help with having a calming effect (Feliway® diffuser/ spray).
Re-Directed Aggression

Re-directed aggression occurs when a cat is aroused and agitated by an animal or person who they can’t get to due to a barrier (such as a window or door). Unable to get to the trigger, the cat may lash out to anyone (human or animal) nearby or approaching the cat.

  • Watching another cat through a door or window
  • Loud noises
  • An altercation with another cat in the house.
  • Watching or stalking birds or other prey animals.
  • Smelling another cat’s odour on a family member, a visitor or clothing.
  • Being frightened or harassed by a dog.
  • Having a person intervene in a cat fight.
  • Being in an animal shelter, surrounded by the sight and smells of other cats.


  • The best way to prevent this aggression is to avoid the stimuli: preventing access to window sills, covering windows or keeping stray cats away.
  • Avoid handling the cat if they appear stressed.
  • Gradually desensitise the cat by small amounts of exposure to the fearful stimulus.
  • Give the cat a food reward while they are calm during the situation. This reinforces relaxation during exposure to the situation.
  • Sometimes medication can be used in combination with behavioural modification (speak to your vet).
Pain-Induced Aggression

Cats that are in pain may act aggressively toward people or other pets in an attempt to avoid touch, movement or certain activities that might worsen the pain. For example, cats with osteoarthritis may resent having their joints touched, and may bite, hiss or scratch in response.

Owners can manage pain-induced aggression by working with a vet to establish a plan for pain management and refraining from touching painful parts of a cat’s body.

Territorial Aggression
Both male and female cats are territorial, but males defend larger territories than females. Territorial aggression is normally directed toward other cats, but sometimes can be directed to dogs and humans. A cat can show territorial aggression to some family members and not others, and some cats but not others. Cats mark their territory by patrolling, rubbing their chin and urine spraying.

Common situations that trigger territorial aggression:

  • New cat introduced into the house
  • Kitten reaches sexual maturity
  • Major changes (such as moving house)
  • Stray or roaming cats entering their territory.


  • Remember to not rush introductions (new cats) or re-introductions. New or returning cats should be kept in their own room with food, water and litter tray. After a few days, replace the new or returning cat with the cat at home (or aggressive cat) and close the door for 30 mins, then return the cat being introduced back to his own room and the aggressive cat back to the rest of the house. This step can be repeated for a few days.
  • The next step is to put the cats on opposite sides of the room so they can see each other but not interact: you can feed them at the same time: as long as the aggressor will not attack. This is so they associate a positive experience of being fed in the presence of the other cat. A leash or harness may help. If they won’t eat, move them further apart. This step should be repeated over days or even weeks, making the distance between them smaller. Once the cats are getting used to each other with restraint and feeding, release them in the same room at a distance and feed them. If any signs of aggression occur, restrain the cat and resume feeding at a safe distance until the cats calm down. This process can take weeks or months, depending on the cats’ temperaments. It is important to bring the cats further apart if any growling or signs of aggression. This process must happen gradually, otherwise if the new cat is attacked or frightened this can make the process take longer due to setbacks. Also be careful not to put your hands or body parts between the cats if they are fighting: use a barrier, such as cardboard or plastic to separate the cats.

If you would like more information on feline aggression, please contact your local Vetwest veterinarian.







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