Feline aggression     See psychological problems

Aggression can vary from a cat pouncing on you as you walk past it, to outright nastiness (hissing, biting and scratching) when you go near it. The former is usually due to either anger transference or a form of anti-social play (bullying).

The link between aggression and nutrition seems obvious in many species and is related to the role of  neurotransmitter serotonin. Tryptophan is the precursor of serotonin, and some authors have hypothesized that dietary supplementation of tryptophan should be beneficial in case of aggression. This has been studied in dogs in complex studies including different kinds of aggression and different kinds of diet. No such studies exist in cats, but clinically we do see a link between food and aggression. Many of these aggressive incidents occur in the hour just before the meal in cats that are fed only once or twice a day. Whether variations in the level of serotonin explain this state of irritation in unknown; however, we do know that frustration and hunger (one can be linked with the other) can trigger arousal and aggressiveness. Therefore, when a cat exhibits aggression, the first approach to therapy may be to check the cat’s feeding schedule. When the cat has only one or two meals a day, the first change prescribed will be to increase the number of meals without increasing the total daily amount of food. It is also important to use motivating food or to distribute in a motivating way. We advise owners to hide some food in different locations and to encourage the cat to find it. In simple cases, this modification, which attempts to approximate natural feline feeding behaviour, can be sufficient to improve behaviour, further illustrating the link between nutrition and behavior¹. When faced with feline behavioural disorders, nutrition is obviously not the only tool for the practitioner, but it can play an important role in the prevention and treatment of many behavioural (and medical) conditions.

Physical diseases can contribute to changes in temperament and these should be excluded as part of a routine physical examination. Diseases which can cause significant changes to a cat's temperament include:

Mild aggression

Mild aggression takes many forms and has many causes, but two basic types occur.

1) Anger transference - This is usually a result of the cat being angry about something and taking it out on you. It can occur at any age, and is seen in all breeds of cats. It may not necessarily be your fault, but as we know in all relationships, it is usually those closest who get hurt. Sometimes the cat can be angry because there is another cat terrorising it outside the house and it can't go outside and sort the problem, so instead it takes out this pent-up anger and vents it on its owner. It can also be caused by the cat having a physical problem such as arthritis or cystitis which causes it physical pain and frustration and because of this, lets out its frustration at the owner. Sometimes treating this problem involves just looking at what could be causing the cat to be angry. Is there a stray cat hanging around? Is there a new baby in the house, or have you moved house recently? Often finding the source of the aggression can be the first step to find a solution or at least understand why your cat is acting strangely. Products such as Feliway® which is a pheromone can help reduce anxiety when it is due to other cats causing it to feel anger.

2) Anti-social play - this is a common problem with younger kittens that are either used to bullying the other kittens or is a kitten that has been reared as a sole kitten and hasn't learnt its own strength. The best way to change their behaviour is either to lock them in a separate room when they do it, or to use a water spray. This behaviour is normally something a cat grows out of by the time it is eighteen months of age. 

Moderate aggression

This aggression usually shows as a reluctance for the cat to want to behave, to bite or scratch unnecessarily and when being handled or groomed becomes highly aggressive. Such aggression can be caused by pain, inherent personality problems (a naturally 'agro' cat), because of another cat being present that threatens it, because it is scared (e.g. the presence of a new baby in the house), if it is a queen that has just had kittens or if it just the sort of cat that doesn't like being patted. The borderline between moderate aggression and severe aggression often depends on how much the cat is provoked. Obviously any cat that is cornered or made to experience something unpleasant such as being tormented by children or being given an injection by a vet will show various amounts of aggression, but when it can't be predicted or controlled by the owner, this is usually called moderate aggression. Such cats required a firm hand (but not aggression by the owner) and a strong tone of voice. Cats that are habitually aggressive a lot of the times require medication as it is difficult for the owner to walk around wondering when the cat is going to strike next. It is not unusual for cat owner to sometimes wondering whether their aggressive cat should be on Valium or they should take it themselves. Obviously when it gets to this point, the use of drugs is warranted, at least in the short term. Drugs such as Valium, Clomicalm and Prozac (Fluoxetine) do have some degree of reducing aggression but often the vet will prescribe a drug called MPA (Medroxyprogesterone acetate). This is an injection of a pregnancy hormone which has the effect of making the cat feel relaxed. The advantage of MPA over drugs such as Valium is that it has no sedating effects, so the cat is not sleeping all the time.

Severe aggression

If a cat is severely aggressive and has only been so recently, it usually has to be managed with medication. Cats that do not show signs of a response to medication usually require euthanasia because of the risks of injury to people. Many cats that are euthanased at cat shelters and veterinary clinics are put to sleep because of serious aggression problems where it is unlikely that proper control of the cat can be achieved.

It is inhumane to imprison a cat in a outdoor run for the rest of its life because it has an aggression problem, but many cats suffer this fate because the owners do not wish to part with their beloved moggie. It is understandable where the owner is coming from emotionally, but one must ensure that the cat has sufficient quality of life in such a prison. Obviously it is a better fate than being put to sleep, but only if the owner has had veterinary advice about the matter and ensures that the cat had access to a suitable run area, with toys and scratching posts in order for it to have a decent life.

1. Beata, C. (2007) FELINE BEHAVIOR: CAN NUTRITION REALLY MAKE A DIFFERENCE? Max' Annual Rescue Newsletter. www.maxshouse.com