A Jack Russell terrier is a breed of small tan and white terrierdog. JRTs are lively, active, energetic and loyal to their owners. They can also be extremely 'yappy' and occasionally aggressive to smaller animals (eg cats, rabbits) because they were bred for hunting rats and small game.
The breed was developed by, and is named for, Rev. John Russell (1795 - 1883) of Devonshire.
