You could also ask why cats growl when playing or why they growl at humans? I know why cats growl because my cat produces the definitive reason for growling. He does it rarely but when he does do it it’s because he has a mouse or a bird in his mouth and he has come charging into the home to play with it and devour it.
If I try to get it off him, rarely he may growl at me. It is abundantly clear what he is saying to me. I should go away or to put it more rudely, piss off. He is protecting his prey from other predators who might want to take it off him. Even if his growl is directed at a friend like myself. He knows me intimately. He knows that I am friendly and would not harm him or take prey from him but, by instinct, he protects it.
Demand to stay away
Therefore we can say that the reason why cats growl is to tell other animals including the human-animal to go away. It’ll be combined with a body posture which adds to the communication. It’s a form of vocalisation which is made in close proximity to other. My cat may also growl when he believes that a hostile creature is threatening him. That hostility may come from an unknown source. The growl is a sound which is often directed at other species and perhaps particularly the human.
Relatively rarely domestic cats may growl, hiss or scream during play with a person or another cat. Once again the growl means same thing: to stop, to go away because it hurts. Sometimes when young cats play with each other they can overdo it resulting in one cat complaining to the other. This teaches them how far they can go.
It is interesting to read an article online by a woman who said that her dog growled at her as she came up behind her dog while she was “working on a pig ear”. The same motivation applies. Her dog wanted her to leave her alone and not take that pig ear from her.
A lot of domestic cat vocalisations are learned to be directed at people; typically the meow which is often a request. Cats are very quiet towards each other unless they are engaged in some sumo style stand-off in preparation for a full-blown fight. Then they produce this strange ‘ohwah’ sound (a guttural yowl) which normally sends one of them away, which means they avoid being hurt.
Pain caused by another
Cats may sometimes growl when they encounter pain. This is more likely to occur, in my opinion, if your cat is in discomfort anyway (perhaps due to an illness causing tenderness inside the body) and by picking her up you cause direct and immediate pain. Under these circumstances the sound means the same thing. It means that you should go away or in other words let her go and don’t pick her up. Cats will not growl simply because they’re in pain but because the presence of another animal including the human-animal causes that pain. The reason here is the same as that described in play i.e. causing pain.
Most domestic cat calls function in close-range situations. These include the purr, hiss, spit, growl (as mentioned), meow and gurgle. The caterwaul is made in the context of sexual activity. There is a huge overlap in the vocalisations made by domestic cats and wild cats. For instance, tigers growl as well as do many other wild cat species.
If your cat has growled at you or another animal then please leave a comment and tell me about it.
SOME PAGES ON CAT SOUNDS: