Jack Russell Terrier are small sized dog breeds belonging to Terrier group, originating from the United Kingdom. It grows to a height of 15 inches and weighs in between 11-18 pounds. Their gait is smooth and far reaching. Their coat is short, smooth and glossy. They are aggressive and boisterous with strangers, other dogs, and pets. Their hunting instincts, make them wary of other pets. They are fearless and brave, known for their barking.