
Is a wagging tail always the sign of a friendly dog? If your cat rolls on her back, does she really want you to rub her tummy?If your dog is “smiling” does that mean he is happy? As a veterinary behaviorist, I have to tell you, the answers to these questions might surprise you.
There are some common behaviors that our dogs and cats exhibit that many people often misinterpret. Let’s review some canine and feline body language in order to help you determine what your pet is really trying to tell you.
Weigh the Wag
For example, tail wagging is not necessarily a sign of friendliness. In dogs, a wagging tail is an indication that the dog is willing to interact, but that interaction can be either aggressive or friendly. In order to determine what the dog is “saying,” you need to look at the rest of the dog’s body posture to figure out if he is approachable or not. Are the dog’s ears pinned back and flat against the head, sort of like a seal’s? Is his body and/or head lowered? Is he avoiding direct eye contact? Is he holding his body still or is he perhaps leaning away from you? These are all signs that the dog is uncomfortable and wants to avoid further interactions. Also keep in mind that a dog may not always choose to leave your vicinity in order to avoid a confrontation. Just as some people might just turn away from someone to avoid a conversation rather than move all the way across the room, a dog might try to stand, turn his head or hold his body away from you if he is uncomfortable. On the other hand, if the dog is being friendly, you might observe that he comes over to you and presents his side or hindquarters to be petted or scratched. He may nudge your hand for attention or press his body up against you. Or, when you look at the dog or speak to it, he may move closer to you for more attention and not bark or growl as he approaches.
In cats, a “wagging” tail is definitely a sign of agitation. Cats don’t really wag their tails like dogs do. When relaxed, they tend to hold their tails quietly with minimal movement in comparison to a dog. So if a cat is moving her tail back and forth quickly two or three times in a motion I describe more as “whipping,” this might indicate agitation. It means something has caused the cat to be aroused, and it is best to give her some space and not interact with her until she has calmed down.

Tummy Troubles
Another behavior that we as humans often misread is when an animal rolls over onto its back. This is not always a sign that he or she wants a tummy rub. When a dog lies on his back, he is showing a sign of utter submission and appeasement in the dog world. People have chosen to interpret it as a sign the dog wants a belly rub. Many dogs may simply like attention, will take it any way they can get it and have learned to love their belly rubs. Other dogs, however, may feel really threatened by someone leaning over them while they are showing their most ultimate form of appeasement. Submissive behavior is deferential behavior used to tell the other dog that he wants to avoid conflict or a confrontation and that he needs space. When a dog rolls over onto his back, I typically ask him to sit up first before I give him attention to avoid this potential problem. Some people are really surprised when they try to pet a dog’s belly and he growls or snaps. While some dogs have been conditioned to receive attention in this manner and maybe even have learned to like it, always keep in mind that in the natural order of things, this is actually a signal saying, “give me space” or “do not hurt me.”