You can generally tell if your dog has a stressful nature or not. I'm not quite sure if it depends on the breed. For example, my family has had three dogs. Two were Dachshunds and one is a Labrador Retriever. The Dachshunds were very nervous dogs. They'd get excited and upset easily. One of them was cranky and the other was just crazy. I would say they were both very stressed out and kind of all over the place. However, our Lab is not like them at all. She is very calm and relaxed. She is super friendly and loving. She wags her tail most of the time. You can tell that she is a relaxed dog and not stressed out. Sure, dogs go through certain periods of stress. We took one of our Dachshunds to a kennel when we went on vacation and had to come pick him up. While we never took our Lab to one, I don't think she would have acted the same as he did.