Why does a cat suddenly attacks for no reason?

Has your cat ever attacked you, another cat or your dog for no reason? At least, for no apparent one? There may be several explanations, but so-called redirected aggression is the most common one.

Redirected aggression in a cat
Photo by Brianda Zuñiga, cc

Redirected aggression happens when a cat is aroused by some stimulation but then directs his annoyance toward the closest unrelated target. For example, if a cat is stressed because he saw a neighborhood cat through the window, since he could not attack it, the cat discharges his energy by attacking anyone who gets in the way.

See any parallels in human relationships? People who are not allowed to yell at their bosses or clients often requite their family members by being grumpy with or yelling at them.

How to identify redirected aggression

Cat aggression is complex due to the fact that it has various possible causes. If you came here because your cat is showing apparently unprovoked aggression, know that there are several possible explanations.

Medical conditions, either those affecting the brain or causing pain, can drive aggression that, to an owner, appears unprovoked. If a cat shows defensive signs, such as hissing, flattening the ears, and thumping the tail, before attacking, aggression is more likely to be caused by fear. Confident assault, on the other hand, could signal territorial aggression.

The surest way to confirm redirected aggression is identifying the source of agitation. Possible triggers are mentioned below, but keep in mind that an event that leads to aggression can occur up to several hours before the aggression takes place. You are also likely to notice your cat’s nervousness prior to the attack.

How to deal with redirected aggression in cats

Knowing what is going on is one thing, but can you stop your cat from directing his anxiety toward you or others? The key solution lies in identifying the source of arousal, and limiting it.

What causes redirected aggression in cats

Cat glaring through a window
Seeing other cats or prey through a window is the most common reason for arousal in indoor cats.

Common triggers of redirected aggression in cats include the sight and odor of an unfamiliar cat, often a neighborhood cat seen through a window. A cat can also be wound up by seeing prey, such as birds or squirrels, outside.

To deal with these issues, you can either block your cat’s access to a window, such as by placing flower pots or double-sided sticky tape on the window panes or by moving the cat tree away. Alternatively, you can cover the lower part of the glass with paper or, for a more sophisticated look, an opaque window film. Deterring cats from your garden or moving bird feeders out of sight can be an equally successful strategy.

Other things can set your cat off, too. Unpleasant sounds, strangers, or unfamiliar environments or items can all cause redirected aggression. Basically, any source of stress can make a cat high strung.  We can’t discuss every single one of them, but there is likely something you can do to limit your cats’ exposure to these stressors.

Unfortunately, the situation may end badly. A cat that becomes anxious regularly might easily learn that his tension can be relieved through an attack. Thus, it’s not rare for a cat to deliberately seek out his victim whenever he is upset.

If the cause isn’t avoidable, you can train your cat to stop stressing about the cause. The principle is to pair the arousal stimuli with something positive, such as feeding time. However, this is something you should do with the assistance of a professional animal behaviorist.

It’s possible that more than one source of agitation exists. You might not be able to limit all of them or even identify them all, but removing several of them, and the most significant ones, is likely to reduce your cat’s agitation and aggression toward you and other pets.

Learn to recognize an agitated cat to prevent fighting

It might not be easy to limit the source of your cat’s agitation. Actually, most cats become stressed and wound up at one point or another, so it’s helpful to get to know your cat.

Alerted, nervous cat
Pricked ears, a fixed gaze, and apparent nervousness are telltale signs of an alerted cat.

If the cat directs his aggression toward you, you must learn to recognize an alerted cat and avoid contact with him during this time. Signs include nervousness, agitation, piercing ears, nervous pacing, thumping of the tail, and fixed-stare low vocalizations.

If your cat is alert most of the time, you likely need to consult with your veterinarian or an animal behaviorist.

If the cat attacks you, it’s best to place an object between you both, such as a wood board or a pillow. If the following works, you cam startle your cat with a loud noise or revert his attention toward a toy. Use either a toy on a string or a ball or mouse you can throw.

If you have time before the cat attacks, walk away. IMPORTANT: Do it emotionlessly. If you scream and run, your cat gets a signal to increase his effort next time. Remember, fear shown by the target, be it human or a cat, encourages more aggression.

If your cat attacks another cat, you must break up the fight and separate them both. When cats are fighting, the best way to stop the fight is to throw a blanket on them, or stuff a pillow between them.

Then, physically separate the cats as they become calmer. Place an aggressive one in a closed room. Make sure that he has water and a litter box in the room. Basically, you will now have to go through the lengthy process of re-introducing both animals as if they had never met before.

Start by keeping them completely separate, allowing interactions through sound and smell. Later, you should gradually add some visual contact, simultaneously giving food rewards to both animals. The process of introducing two cats is described here.

Do not punish your cat for being aggressive

Of course, you have to restrain your cat or push him away if he attacks you. However, once the situation gets under control, do not yell at, throw things at or chase after the cat. Aggression will only cause more aggression.

Think about it: If your cat attacks because he is aroused, yelling at him will only make him aroused even more. Instead, you need your cat to calm down. And yourself, too.

If you can, lure your cat inside a separate room. if not, just leave him alone and remove the victim from the scene. That is, if it’s another cat. If it’s you, then just walk away.

Increase your cat’s activity

Cat playing with an interactive toy
There is no better target for your cat’s anger than a toy. Tambako The Jaguar, CC BY-ND 2.0

When a cat redirects his agitation toward an innocent target, you can make him choose a more appropriate cat toy.

Think of it: A cat gets wound up, it does not matter why, and is willing to literally kill someone. You can let him attack your other cat or you, or you may dissolve his energy during playtime.

Even more, don’t wait for your cat to become aroused. Develop a habit of playing with him regularly; this is best because it resembles natural hunting behavior in cats.

Playing helps to relieve tension and remove the necessity to attack in the first place. Besides playing, there are other ways to keep your cat active.

Nevertheless, the most important thing is that you learn to recognize and predict those moments when your cat is aroused. Avoid handling your cat when he is nervous, and/or remove other pets from the site until you manage to calm him down.

And, because of the complicated nature of feline aggression, consider involving a veterinarian or animal behaviorist in solving it. If your cat has other behavior problems, you can check our list of their solutions here.

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