I have a 5 yr old shihtzu I also recently adopted a puppy. She is a terriorĂ— at 15 weeks she is 16 pounds. I have her the puppy enrolled in classes and she does quite well in public and class. However at home she bites and tries to eat my furniture. (Bed and couch). I have tried collar grab down, redirecting, time out... She continues to bite me and my room mate. Please help Im at my wits end.