A have a 25 pound 1/2 jack Russell/ 1/2 cattle dog. He does great with my two shepherds. He holds his own just fine. My brother has a full jack Russell who is more on the timid side but she gets along fine with my dogs. She doesn't have the standard jack Russell personality tho. My mix is more like a jack Russell than her. He can be very vocal, digs up the moles in the yard, has great ball drive, is smart, and can run 10 miles with me without getting tired. He is a fun little dog.
Kelby's Charlotte Rose "Charlie" CGC 04-15-07
Captain Von Der Staatsmacht "Dude" BH 10-26-11