Cat - Diagnosing and Treating Aggression

Aggression can be a serious and dangerous behaviour problem for cat owners.  There are many different motivations for aggression and making a diagnosis, determining the prognosis (the chances of safe and effective correction) and developing an appropriate treatment plan are usually best handled by a veterinary behaviourist or feline behaviour specialist (with appropriate qualifications).  In very rare circumstances, aggression has no identifiable aetiology (cause) usually referred to as idiopathic aggression, and no particular stimuli that initiate the aggressive displays.  There may be a genetic predisposition to such aggression.

To treat aggression, it is necessary to determine whether there is an underlying medical reason, whether the behaviour is the result of an emotional reaction and subsequent learning, or whether both are playing a role. For this reason, before a behaviour consultation is held your cat should have a thorough physical examination and possibly blood tests to rule out organ dysfunction, since in some cases medical conditions can contribute to aggression. It is therefore best to talk to your general practice veterinary surgeon in the first instance and then arrange referral to a specialist behaviourist if appropriate.

It is important to determine the circumstances in which your cat shows aggression and whether the aggression is directed toward family members, strangers, other pets in the household, or unfamiliar pets.  Keeping a diary of the behaviour can be particularly useful in evaluating the nature and severity of the problem. 

Behaviour modification techniques and/or changes to your cat's environment will be necessary to correct most aggressive problems.  Drug therapy can be a useful part of treatment for some forms of aggression but it is never the complete answer and should only be considered after in depth discussion with a veterinary behaviourist.

Fear motivated aggression:  what is it and how is it diagnosed?

Fear motivated aggression can arise when a cat is exposed to people, other animals, places or stimuli (e.g. noises) which the cat is frightened of.  The fear may result from previous unpleasant experiences which are associated with the stimulus, or from a lack of experience of the stimulus in the past.  The primary defence strategy of the cat is flight and many cats retreat from a situation when they are fearful.  However, when a cat is prevented from retreating because it is cornered it may change its strategy to one of fight.  If the stimulus (person or animal) retreats or the cat is harmed or further frightened in any way (e.g. the person or other animal becomes confrontational), the aggressive response is likely to be reinforced and potentially the fear can be further aggravated. 

People or animals that do not approach in a calm, confident or friendly manner are more likely to be met with a fearful response.  Fear motivated aggression toward family members might arise as a result of the use of punishment or due to other experiences associated with them which the cat has perceived to be unpleasant.  Fearful body postures in conjunction with aggression are useful indicators of a diagnosis of fear motivated aggression.  Behaviour therapy will be the main component of any treatment programme but drug therapy may be considered necessary as an adjunct to the treatment in some cases.

Play or aggression: which is it?

When cats play, aggression may be seen as part of that interaction, but in some cases the aggressive component is excessive or out of context.  Young cats may begin to use teeth and claws in their interactions with people or other pets in the family and sometimes the reaction to those attacks serves to perpetuate rather than control them.  Overly rambunctious play, along with grabbing, stalking, pouncing, nipping or biting of people or their clothing are common signs of such inappropriate play.  Although play is a normal behaviour, these extremes of aggression, albeit in a playful context, can lead to injuries.  If handled incorrectly it could lead to more serious aggression as your cat matures.

Defending the territory

Aggression can be exhibited toward people or other animals (usually other cats) that approach or reside on your cat's property.  Such aggressive responses may be a perfectly natural way of defending the territory from intruders but in some cases it is not outsiders, but rather cats that live in the household who are the victims.  Aggression is often manifested when a new cat is introduced or when resident cats reach social maturity at 2-3 years of age.  When aggression is being directed toward people or other animals entering the property fear or anxiety may often be involved in the motivation for the behaviour.

Pain and aggression

Aggression that is only elicited by handling or contact may be associated with pain and, while the source of acute pain may be very obvious, it may take some time to identify the causes of chronic pain.  Even if your cat is not obviously exhibiting pain responses it is important to remember that cats are very adept at masking their pain and the symptoms are often passive. Also, certain medical conditions (endocrine (hormone) imbalances, organ disease, etc.) may make the pet more irritable and prone to aggression during handling even when pain is not a component of the condition.  Fear and anxiety (caused by the expectation of pain in a specific situation) can further compound many of these cases. If your cat is showing other behaviour changes, such as reduced time spent in high places, this may be very significant as it could indicate a reluctance to jump or climb due to arthritic pain.

Once your cat learns that aggression is successful at removing the stimulus, aggression may recur when similar situations arise in the future, whether or not any pain or disease is still present.  Treatment requires that the medical or painful condition be resolved first.  Next it will be important to identify the types of handling and situations that have led to aggression in the past.  With desensitisation and counter-conditioning your cat can slowly and gradually become accustomed to accept and enjoy these situations.  Once your cat learns that there is no further discomfort associated with the handling, and that there may be rewards, the problem should resolve.  If it does not resolve you should ask your veterinary surgeon about referral to a suitably qualified behaviourist.

Redirected aggression:  what is it and how can it be avoided?

Aggression that is directed toward a stimulus (person or pet) that did not initially evoke the aggression is sometimes referred to as redirected aggression or frustration motivated aggression.  This is likely to occur when your cat is aroused (tense) and a person or other pet intervenes or approaches.  Cats that are highly aroused are best avoided.  Since redirected aggression can occur with any form of aggression, it is important to identify and treat the initial cause of aggression (e.g. fear, inter-cat conflict) or to prevent the problem by avoiding interacting with cats who are in a state of high arousal.  You can identify a high arousal state from behavioural signs such as dilated pupils, a rapidly swishing tail and the hair on your cat's back and tail being fluffed up.

Learned aggression: what is it and how can it be treated?

Learning is an important component of most aggression, regardless of its motivation.  Whenever your cat learns that aggression is successful at removing the stimulus, the behaviour is reinforced.  Some forms of aggression are inadvertently rewarded by owners who, in an attempt to calm the cat and reduce aggression, actually encourage the behaviour with patting or verbal reassurances.  On the other hand, cats that are threatened or punished for aggressive displays may also become even more aggressive each time the situation recurs.

Treatment is aimed at dealing with the underlying motivation for the aggressive responses and teaching the cat that the stimulus is not associated with any harm and that aggression will not successfully remove the stimulus.  With desensitisation and counter-conditioning, your cat is not only taught that the stimulus is safe, but also that it is associated with a reward.

Predation - a natural behaviour

Although not true aggression from an emotional perspective, this is included here for completeness. Predation is the instinctive tendency to chase and hunt prey.  Predatory behaviours include stalking, chasing, attacking, and ingesting of prey animals, but in some cases these perfectly natural behaviours may be inappropriately directed toward people or other pets.  Although the desire to chase can be reduced by using desensitisation and counter-conditioning in the presence of the stimuli, the aggression can be very severe in some of these cases and prevention is better than cure.  If the behaviour is directed toward small pets in the home such as hamsters, confining those pets to a room where the cat does not have access is the best solution.  If the behaviour is directed to animals and birds outside, then keeping the cat indoors has been suggested as a possible solution but it must be remembered that cats are finely tuned hunting machines and the behaviour is perfectly natural.  Keeping them permanently indoors when they have already enjoyed an outdoor existence can cause more behaviour problems than it solves especially if you do not adequately compensate for the change in lifestyle by providing your cat with adequate stimulation within the home.

Why should I speak to my vet if my cat is being aggressive?

Aggression associated with medical disorders may arise at any age, may have a relatively sudden onset and may not fit any feline species typical behaviour.  Some medical conditions can, on their own, cause aggression, but in many cases a combination of behavioural factors and medical problems cause your cat to pass a certain threshold at which aggression is displayed.  Infectious agents such as rabies, hormonal imbalances such as hyperthyroidism, psychomotor epilepsy, neoplasia, and a variety of genetic and metabolic disorders may cause or predispose a cat to aggressive behaviour.  Painful conditions such as dental disease, or arthritis, and medical conditions causing fever, fatigue or sensory loss might also increase the cat's irritability.