My dog was playing with my daughter and nipped her . not hard and didn't break the skin but there is visible redness and it aches and she says it feels warm. It is on her wrist. Idk if this is cause for concern because it did not break the skin. She has an ice pack and aloe Vera on it. I did clean it just to be safe I think because he is a larger dog it was scary since we just got him. He was not being agressive when it happened either.