The Jack Russell Terrier takes its name from the Reverend John Russell, a nineteenth-century hunting parson in Devon, England, who wanted white working terriers that could keep up with hounds and bolt foxes from their dens. Today's dogs are compact, mostly white, about 10 to 15 inches tall, with black or tan markings and smooth, broken or rough coats. The taller show type is registered in the United States as the Parson Russell Terrier.
Many Jack Russells are bold, clever, tireless and funny, with a big prey drive and a talent for digging, climbing and escaping. They can be wonderful companions for people who enjoy training and outdoor time, but they are rarely couch dogs. Daily vigorous exercise, mental challenges and firm, positive boundaries make the difference, and many Jacks end up in shelters because their energy was underestimated.