Not every cat is a lovable ball of fluff, even if she looks the part. Cats are naturally aggressive animals, so it is not uncommon for a feline to become violent toward you or other animals. An aggressive cat is not a lost cause though, so don't give up.
Fear
A scared cat is a violent cat. No matter how tame or gentle your kitty is normally, his claws will come out when he is afraid. A cat may experience fear aggression when a strange person or animal enters the house or if you take him to an unfamiliar place, like the vet's office. Some cats will flee when they are scared, but some will attempt to attack the source of the unpleasant stimulus. Remove the source of your cat's fear from the area if possible. You can encourage a positive association with that stimulus in the future by offering your cat treats or playing with him during the experience, according to Maddie's Shelter Medicine Program.
Competition
Cats violently compete with one another over mates, food and places in the social hierarchy. Like most feline species, domestic cats often establish a roughly pecking order among themselves. While the social order can be created peacefully, there will be at least a few physical altercations here and there as your more ambitious kitties try to move up the ladder. Some cats may also display food aggression, threatening nearby cats during mealtime. Feeding your cats separately, especially if you're dishing out something tasty like treats or wet food, can help mitigate this problem.
Play-Fighting
Every cat owner knows that felines love to play, but not all of them know why. Felines don't just play for the fun of it. They play-fight to hone their senses, strength and agility. Since their play is actually practice for hunting, it should come as no surprise that claws and teeth may come out during a session of chase-the-string. Play-fighting is the most common source of "aggressive" behavior in cats, according to the Tufts Cummings School of Veterinary Medicine.
Managing Aggression
Don't console, pet or reward your cat while he is actively displaying any kind of aggression; doing so encourages undesirable behavior, according to Cornell University College of Veterinary Medicine. If your peaceful outdoor kitty comes home with battle scars, you may want to consider confining him to the house or keeping him in an enclosed area of the yard. Even if you can trust your cat to be diplomatic, you can't trust strange or feral cats to do the same.
Don't force yourself onto an unfriendly cat. Build trust with him by respecting his personal space. Stretch your hand low to the ground and allow him to walk up to it. You should also consider getting your cat fixed, especially if you have a male, to reduce the biological sources of aggressive behavior.
References
Writer Bio
Quentin Coleman has written for various publications, including All Pet News and Safe to Work Australia. He spent more tan 10 years nursing kittens, treating sick animals and domesticating semi-feral cats for a local animal shelter. He graduated from the University of Delaware with a bachelor's degree in journalism.