Ultimately, you will not need to know; that is what you are hiring me to know. It is important though, for you to know that you still have a claim against a dog-sitter, e.g., where the dog-sitter is the one with assets and/or insurance, and the dog owner does not. Maybe you do not want to press a claim against the owner, for whatever reason, but you feel that the dog-sitter is the greater threat.
Another reason for us to be concerned as to how to proceed, is that you are concerned about a potential provocation defense succeeding under the statute, leaving you empty handed. By making a claim under common-law negligence as well, you might well be protected from being tossed out of court by a provocation defense under MCLA §287.351. However, bear in mind that if you are concerned about a provocation defense, you will also need to be concerned about the damages reduction provisions of MCLA §600.2955a and MCLA §600.2959.