My dog used to be my sisters and before my husband and I owned him my parents were dog-sitting him and my sister's other dog. The dogs broke into my side of the house and killed my cat. I was the one that found him and was devastated (I adored this cat) but even then I knew it wasn't a malicious death, there was absolutely no blood. The cat's neck was broken and we knew my dog was prone to grabbing the neck and shaking when he wrestled, so we assumed he was the one that had killed my cat. A few months later my sister told me the dog wasn't doing well at their house and so he came to live with me and my husband. He's doing very well with us and is the best dog ever. He is affectionate, quiet, obedient, and very gentle. He gets along especially with smaller dogs and is always very gentle and careful with them. My question is, ever since my cat died, I have not seen him grab and shake like he used to, is it possible that when my cat died he felt bad and so stopped doing it?