I have a new puppie that is a little over two pounds .it appears to me the cat[20lbs.] is trying to kill it. The cat seems to have been in a hunt /alert behavior since we brought it home. It watches it intently and from time to time they sniff each other and the pup will chase him. However,when they sniff the cat sneaks under the dog and, it seems she is trying to bite it's throat. I don't know if this is territorial,dominace or more of a kill position for the cat . There is no hissing or swatting just that move to sniff the nose and then move under the pups throat and bite.