Generally speaking, the terms man and woman are reserved specifically for humans. I couldn’t tell you why, but I suppose it doesn’t really matter.

For pets, the use of boy/girl probably does have a lot to do with how people tend to infantilize their companion animals.

Additionally, the boy / girl terminology is often generalized to cover all animals, particularly when adults are interacting with children and by extension when children are interacting with each other. It’s not uncommon to have a child ask something like “is that a boy rabbit or a girl rabbit?” but it is a little unusual to hear an adult ask another adult that same question, unless it’s sort of tongue-in-cheek or maybe in the presence of kids.

nostupidanswers? cuz there are no man cats or woman cats. That’s some weird human-cat chimera shiz.

Because they are all fur babies. Always.

You can call your cat anything you want, they still won’t come.

My 16yo cat is definitely a prim and proper old lady. Oddly, I call the 4yo Maine Coon “little man” even though he’s easily 4x the old lady’s size

I’m probably forever going to call my dog “bestest girl”, but she’s starting to get a grey muzzle too

IMO:

Boy/Girl cat implies gender.

Man/Woman cat implies anthropomorphism.

Because that would be a cattasrophe!

because they stay smol!

Because they get neutered/spayed

My cat was an “old man cat” for a while before he passed.

Anyhow, a “man cat” just sounds like a cat who dresses up like a man and fights crime

My cats are gentlemen and ladies

I can hold onto many feelings and ideas at once.

My orange baby boy is an old man.

The only true man cat is Idris Elba in Cats

Because kitties are forever babies 🤗

Human/animal bonding is added because their faces retain neotenic features that remind us of babies.. So many are inclined to relate to them like children.

From that article:

Accumulating behavioral and neurophysiological studies support the idea of infantile (cute) faces as highly biologically relevant stimuli rapidly and unconsciously capturing attention and eliciting positive/affectionate behaviors, including willingness to care. It has been hypothesized that the presence of infantile physical and behavioral features in companion (or pet) animals (i.e., dogs and cats) might form the basis of our attraction to these species.

It has been hypothesized that both behavioral and physical infantile features present in companion animals might form the basis of our attraction to these animals and may bear some part of the responsibility for our motivational drive to pet-keeping and pet-caretaking (Archer, 1997).