As the name indicates, redirected aggression is aggression towards a person or another animal even though the cat's original focus of aggression was on something else. For example, if your cat encounters a trespassing cat on her territory a territorial dispute will probably occur. This leaves your cat very agitated and aggressive. On returning to the house she still has not had time to calm down. Now a sibling/playmate pops out to play, or a human innocently tries to stroke the cat, and the cat lashes out, transferring her anger against the intruder to whichever unfortunate creature next happens to be in her way. Another classic example of redirected aggression is when an indoor cat watching the world through the window sees another cat in 'her' garden. She starts hissing and growling, but cannot get through the glass to launch an attack. Her frustration is at the point of spilling over when you come into the room to see what the fuss is about and try gently gently stroking the cat to calm her down. The cat goes for your hand because she is so angry and frustrated that she cannot dissociate you from the intruder on the other side of the window. And she can't get at the intruder, but your hand is well in reach. Because redirected aggression can be very unexpected the recipient might be left completely shell-shocked by this 'unprovoked' attack.
Below we discuss some techniques for dealing withredirected aggression, but in general this is not an easy character trait to eliminate.
The extent of redirected aggression varies according to the circumstances. A lot depends on what happens to the the cat after her aggressive move. Let's take the first example. The agitated cat comes into the house from the garden and takes her frustration out on an unspecting cat indoors. That cat now retaliates. The battle that started in the garden has now moved into the house. Both cats turn against each other and suddenly a friendly playmate becomes enemy number one. In such cases the cats have to be separated ASAP. Use a water pistol, a puff of compressed air or a loud bang. It's not a good idea to get between the two cats unless you want personal experience of redirected aggression - times two!
Once you have broken up the fight put the cats in different rooms to let them calm down. In most situations once everyone has calmed down the cats will be friends again. However, as with humans, a punch-up might permanently change a relationship and the cat's attitude to the other cats in the household might never be the same. In that case a longer seption will be required. You may have to go back to basics and start by re-introducing both cats as if they were just brought together. Do as you would do when bringing a new cat into a multicat household. This may take days or even weeks, but it is important not to rush the re-introduction. As soon as you see any signs of aggression, separate the cats again. Once they start tolerating each other, start feeding them in the same room, first making sure that the food bowls are well apart, and if that meets with success, over the next few days slowly bring the bowls closer.
With the second example discussed above, the redirected aggression was against a person. In such cases, prevention is better than cure. If your cat is agitated do not stroke her to calm her down. This may well have the opposite effect. Instead try to isolate and remove whatever is winding the cat up in the first place. This can be done in two ways, either take away what is agitating the cat (for example if an intruding cat is in the garden, chase it off) or get the cat away from the problem (by closing the curtains, cat flap etc). Wait for the cat to calm down before approaching her. If the cat has already attacked you, it is up to you to de-escalate the situation. Take a deep breath, remember that you are the homo sapiens and act like one. Above all, restrain your instinctive response to punish the cat. The cat is pumped full of adrenaline, and might well decide to take you on, leading to what might mildly be called a breakdown in relations. Cats tend to calm down more quickly in a darker, quiet room, so try to leave the cat to itself in one. The best thing to do is to draw the curtains, close the door and back off, leaving the cat to relax. Some cats take just a few minutes to calm down, others need hours. If your cat shows any further aggression towards a person by hissing and growling, put some food down and leave her to herself. It is important that the cat does not get into the habit of taking ill-temper out on you, so don't give her the chance.
If the cat remains aggressive for a number of days without showing any improvement, you might have to call the vet to discuss a calming medication strategy. However it is rare for the situation to progress to this point. Some cats show no redirect aggression at all, and positively seek human reassurance when agitated. The secret is as always - know your cat!