Also check our rat terriers. They are much smaller and can have markings and fur color very close to that of a jack russell terrier. Behavior is also very similar lots of energy and smart. I myself have a full size JRT and even other JRT owners think he is big for the breed as they do vary in size a lot and I know mine is pure bread. He weighs in at 27 lbs and is 16.5 inches tall.
They are a wonderful dog, but require someone with a lot of time and energy. Always research any pet thoroughly before purchasing to insure they match your type of life style. You'll both be happier.
Mar 14, 2008 Rating
Possibly A Shorty? by: Marc Neveux
Perhaps what you are looking for is a "Shorty Jack Russell".