Don’t Discount Aggression in Cats


After house-soiling, aggression is the second most common behavioral issue we see in cats. Aggression in cats is not taken as seriously as in dogs, probably because cats are smaller and people simply dismiss their behavior as being normal for a cat or that the cat is simply grumpy that day. This is a big mistake – cat bites and claws can inflict serious harm to their people and other cats, leading to infections and even hospitalization. Key to preventing aggression is understanding the types of feline aggression, their triggers, and some measures to prevent this unwanted behavior.

First, what does cat aggression look like and how is it different than playing? It is not as easy to divine a cat’s intentions as a dog, but body posture and facial expressions are a good start. Aggression can either be offensive or defensive – with both being equally dangerous. An offensive posturing cat will usually have a direct stare, erect ears, straight-legged upright stance, directly face the opponent, and frequently growl. The pupils may also be small. Whereas defensive behavior includes eyes wide open, a crouched position with the head tucked in, ears flattened, hair raised on the back, turning sideways, hissing or spitting, and possibly striking with front paws – claws out.

Why is the cat showing aggression in the first place? First is the cat healthy? Medical problems such as hyperthyroidism, dental pain, arthritis, painful areas and infectious diseases, including toxoplasmosis, can increase aggressive behavior. If given the medical all-clear, carefully observe your cat’s behavior. Can you figure out what made her upset in the first place? Who did she attack? What happened for the thirty minutes before the incident? Where did it happen? These answers will help you prevent future incidents.

Aggression usually does not happen out of the blue: your cat has a reason. There is a purpose to the effort. The most common type is cat-to-cat aggression. Unneutered male cats will have aggression toward others as they stake out their territory. But aggression between members of a household can be more complicated. The instigating cat will posture, while the other cat will make itself look smaller. The reasons for household members to have a dust-up can include size differences, territory claims, redirected aggression (see below), lack of feline socialization, resource guarding, and more.

Cats will posture and display aggressive-type behaviors when they are frightened or threatened. This makes sense- they puff up and defend themselves. They usually assume a more defensive posture, but may become more aggressive should the cat not be able to avoid that which is making it fearful in the first place. Things which may make a cat fearful can include strange people, new objects, unusual smells, being startled, loud noises. If this behavior is seen, back away and give the cat space. If possible, eliminate the inciting cause. The cat should calm down.

Rough play can lead to aggressive behaviors. Kittens and younger cats play in order to learn behaviors essential for survival. The cats learn to not hurt each other when playing, but this inhibition may not be present in cats weaned young or raised by themselves. Therefore when the cat plays with its human, it may swat, chase, nip, and show predatory behaviors. Such behavior should not be encouraged, especially encouraging cats to chase peoples’ hands and feet. Cats also play rough when they have been inactive for long periods of time. We may think cats are solitary creatures and don’t mind being home for extended periods, but they too, require social interaction to have healthy behaviors. A tired cat is usually a good cat.

Redirected aggression can be the most dangerous form of cat aggression as the behavior is uninhibited and can result in serious bites and injuries. This behavior occurs when a cat is agitated or scared by another cat, animal or person, that it cannot reach. The cat will turn to the person or animal nearby and viciously attack them. The most common scenario is a cat watching another cat through a window or a screen door. It can also occur when the cat is frightened, smells another cat on a person, stalking another animal, or of a person tries to break up a cat fight. The time between the inciting cause and the incident can be hours, although it is frequently closely connected to the time of the cause. The attack usually occurs if the person approaches the cat – this cat does not seek out someone to attack. The behavior can be thought of as a reflex – this is why you should leave an agitated cat alone and also not break up cat fights.

The last type we will address is petting-induced aggression. Some cats like to be stroked, others don’t. The cat may tolerate it for a while, but then they are quite suddenly irritated and will let you know. To them, it may become annoying, or static may build up in their fur. Whatever it is, your cat wants you to stop. And you should respect their wishes.

Cats generally do not display aggression without a reason. Discerning the cause may help you and your cat live a more peaceable coexistence. Listen to your cat.

Dan Teich, DVM is Medical Director at District Veterinary Hospital Eastern Market.