Instructions
Observe the cat's body language. If the cat's tail is puffy, or the fur is sticking straight out from the skin, her ears are back or flattened, her tail is thrashing about, her back is arched and she is backing herself into a corner, the cat is probably growling. While cats can purr because they are trying to calm themselves, a purring cat's body language is very different from a growling cat's body language.
Listen carefully to the sound your cat is making. If the sound is not something you can easily imitate, she is probably purring. If the sound is one you can imitate by making low sounds in the back of your mouth and throat, the cat is probably growling.
Attempt to approach the cat. A growling cat is generally unapproachable and will try to swat and back away from you. She might run under a chair, table or bed in an attempt to hide. Purring cats are usually easily approachable and will purr louder once you begin to talk to them and pet them. A cat might flop down on the floor or a bed so you can pet her stomach or rub her face against your hands as well. She also might rub her body against your legs or want to get in your lap.
Listen for other sounds and signs of upset, such as hissing, spitting and yowling. Once you have determined that the cat is growling, it is best to let the cat be until she calms down.
How to Know If Your Cat Is Purring or Growling
Almost all types of cats purr, whether domesticated or wild, though those that roar, such as lions and tigers, do not purr. Big cats that do purr include mountain lions and bobcats, though neither of these species roar. While purring was once thought of as a sign of contentment only, cats may purr to calm themselves when stressed or over-stimulated, such as when going to the veterinarian. Despite this, it is generally very easy to tell the difference between a purring and growling cat, as growling cats display other signs of being angry or upset. Both purring and growling sounds come from the throat and do not require the cat to open her mouth.