NeverMore, a cat's "Meow" is very much like a dog's bark. It can be a greeting, it can be a sign of annoyance, it could mean the cat's unhappy about something, or it can even be a sign of agression. It al depends on the tone of the "meow." A dog's bark is the same thing. The dog can bark to greet you, the dog can bark when he needs to go out for a bathroom break or he's hungry, and it can also be a warning bark to all strangers, human and animal alike, not to tresspass on his terf.