Risk Assessment and Prognosis of Feline Aggression

Key Points

Cat bites are not trivial; they often become infected and can cause severe disfigurement to the hands and face. Aggression is usually predictable, based on the pattern of events and stimuli that precede it, unless the stimuli are internal and not obvious to the observer (such as pain). To safely treat aggressive cats the motivation for the behaviour must be understood and the pattern of stimuli and events that elicit aggression must be identified.

Human Injury Caused by Cat Bites and Scratches

There is limited available data on the prevalence of cat bite/scratch injuries. One Italian study using emergency department treatment records found a rate of 17.9 cases per 100,00, compared with 58.4 pr 100,000 in dogs. Whereas dog bites cause crush, laceration and puncture wounds that become infected on 3-18% of occasions, cat bites usually cause a penetrating injury and 28-80% result in an infection that more often involves Pasteurella multocida and/or Staphylococcus aureus. Human facial injuries due to cat bites are particularly serious, as surgical repair cannot be carried out until microbial infection is eliminated and damaged tissue debrided. Injuries to the hands and feet can result in serious complicates, such as osteomyelitis. Another factor is the rising incidence of sharing of methicillin resistant Staphylococcus aureus between animals and their owners, with infection cycling between the animal and its various human acquaintances, which could become a significant problem infected cat bites

Cat scratch disease is a common and mostly benign condition caused by post-scratch infection with the gram negative bacteria Bartonella henselae or Bartonella quintana. Symptoms are usually seen within 7-14 days of injury, but can take up to 2 months. Symptoms include headache, joint and muscular pains, but severe cases can result in menigioencephalitis or endocarditis. Cats are generally less likely to cause injury to people than dogs, as their primary response to threat is escape and avoidance. The greatest risk of injury is when handling cats, but some cats will actively seek out and attack people.

Risk Assessment

Risk assessment in aggression is a subject that requires proper investigation. There is also little scientific data to provide a reliable means of prognostication. However, the following factors should be taken into account:

• Frequency of aggressive incidents, which have resulted in physical injury, in the past.
• Level of physical damage caused in previous incidents.
• Predictability of aggressive incidents (what events and stimuli elicit aggression, and whether the cat provides adequate warning of its actions).
• Manageability of the behaviour: what measures can be taken to minimise risk of injury.

If bites/scratches have been frequent and unpredictable and with little warning, and it is difficult to institute measures that alleviate risk of injury, then risk is high. Unless the damage caused by previous bites has been minimal, and the underlying cause for the aggression can be treated effectively then the prognosis if poor.

Making an assessment of the owner's willingness and ability of comply with treatment and management instructs if critical; poor compliance can lead to serious injury. After a problem has been successfully treated, there may still be an ongoing risk of incidents, and risk management may need to be continued for the remainder of the cat's life.

In many cases cats show inhibited behaviour and subtle initial signs of fear or anxiety. Clients must be able to identify these in order to fully understand the cat’s behaviour.

Predictability

The apparent predictability of attacks is crucial to the safe management and treatment of aggressive cats. It is very rare for aggression to be truly unpredictable, unless the animal has an impulse control disorder or the stimuli that elicit or contribute to aggression originate internally (e.g. pain or dysphoria). However, the behavioural changes that warn of an aggressive attack are often missed or misinterpreted by owners, leading to an escalation of behaviour that surprises the owner.

Discerning patterns associated with aggression

To safely treat aggressive cats, the motivation for every aggressive incident must be thoroughly understood and a pattern of behaviour identified if possible. The owner should be asked to describe what happened at each event, and not to interpret what happened. The first priority is to use this information to prevent injury.

Signs that a cat is becoming likely to react aggressively include:

• Avoidant behaviour: Running away or hiding, struggling whilst being held and freezing.
• Signs of increased arousal: Pupillary dilation, increased respiratory rate (including panting), trembling, agitation.
• Defensive signals: Flattened or rotated ears, low body posture, body rigidity, growling, hissing, spitting, tail thrashing, rolling onto back.
  

Owners should be taught to identify the above signs and react appropriately (stop handling the cat, move away and avoid eye contact).

It is then important to identify contexts, stimuli, and events that are associated with aggression:

• Contexts: particular places where aggressive incidents have occurred
• Stimuli: noises, movements, unfamiliar people, other cats.
• Human actions/interactions: Handling, grooming, picking up or corning the cat. Shouting/shrieking at the cat, pushing the cat away, sudden movements, threats (raised hand).
• Interactions with other cats: play, competition around resources (food, water, latrines, cat doors).
• Relationship to events or activities: Arrival of a visitor, entry of another cat, play, grooming, feeding, owner departure from the house)
• Timing: The times of day when aggressive incidents, or near misses, have tended to occur.
  
  

One problem with aggression dogs and cats is that the actual number of aggressive incidents may not be large enough to properly identify a pattern. However, "near misses" are as important as actual aggressive attacks; once owners understand the signs that are typical of the build up to an aggressive attack they can usually provide a much more extensive list of incidents that came close to an attack. This is a better guide to the underlying cause of the problem and the triggers for aggression.

If the pattern of aggressive incidents is inconsistent, with the same events leading to completely different patterns of response from the cat, then it is likely that there is either an underlying medical cause, or unidentified stressors are altering the cat's state of emotion and arousal so that it responds variably.

Prognosis

Prognosis depends upon the owner’s commitment to carry out what may be a lengthy course of behavioural therapy, alongside making potentially permanent changes to the cat’s husbandry and environment.

In cases where cats are being asked to live in large feline groups with several unrelated individuals it is important to consider the welfare implications for the cats concerned. In cases of inter-cat aggression within the household, re-homing should be considered as a viable treatment option rather than a sign of therapeutic failure. Despotic cats that terrorise the neighbourhood carry a poor prognosis unless there is considerable co-operation between owners with regards to confinement, either permanent or on a rota basis.

The nature of the aggressive behaviour is important. Defensive behaviour has a better prognosis because it is possible to reduce the perception of threat and to provide the cat with alternative opportunities to deal with fear (such as through escape or avoidance behaviour). Offensive aggression carries a more guarded prognosis unless full recovery from some underlying medical pathology can be achieved. Hyperthyroid cats, for example, carry a good prognosis for reform once the underlying pathology has been treated.

Other indicators of a good prognosis include selection of alternative coping strategies, such as retreating and hiding in cats that are fearful or anxious, and improvements in effective feline communication between warring cats in the same household. Decrease in both the intensity and the frequency of the aggressive incidents should be seen as favourable prognostic signs. Owners often find it difficult to be objective regarding progress in cases of feline aggression and there can be a considerable differential between actual change and the owner’s perception of alterations in the cat’s behaviour. It is therefore essential to persuade owners to keep a daily diary and to record all aggressive incidents, together with notes about the context or trigger for the behaviour. Likewise a record should be kept of affiliative behaviour because a shift in the balance between these types of behaviour is a strong indicator of change.