Yes is is nice to have a really be haved dog. Be careful of your Jack Russel my daughter had one plus a yorkie, and her yorkie and Russell played together for close to a year no fighting or nothing. Then one day the Russel must of had enough and snapped, tore into her and hurt her bad. they had to have the yorkie put down, their was no helping her. my daughter said she was laying eyeing the yorkie then all of a sudden grabbed her. and started growling and shaking her. didn't mean to over take this page ,just thought you should know.
Anne/Luci