"My dog, specifically at nighttime, will randomly growl... I was just petting her gently, and she growled. Other nights, we will just simply move, and she will be lying in her crate, and she'll growl.

Not all dog growls are created equal. Most commonly growls are aggressive signals, however even here there are different meanings. One growl can mean, "Back off! This is mine," as in when a dog is ...