Size and Structure
The Jack Russell Terrier is a small breed, generally standing between 10 and 12 inches at the shoulder for both males and females, and weighing between 14 and 18 pounds. Despite their compact size, they possess a robust, muscular build with compact bodies that exude strength and agility. Their structure includes a level back with a slight loin dip, deep chests with oval ribcages, and powerful hindquarters, supporting their lively movement and endurance.
Coat and Coloration
This breed can have either a smooth or rough coat, both with softer undercoats that provide weather protection. The primary base color is white with distinctive black and/or tan markings, as outlined in the Kennel Club standard. Acceptable coat patterns include white with black markings, white with black and tan markings, and white with tan markings. Seasonal shedding occurs, more pronounced during spring and autumn, requiring regular brushing to maintain coat health.
Unique Characteristics
Notable features of the breed include a flat and moderately wide skull narrowing towards the eyes, which are small, almond-shaped, dark, and expressive with a keen, alert look. Jack Russells have black noses and tight black lips, with ears that may be button or dropped, carried close to the head. The tail is set high, thick at the base, carried upright when alert, and relaxed when resting. Their gait is free-moving and straight, demonstrating efficiency and drive without exaggeration.
Differences Between Genders
Males are typically slightly larger and more muscular, though size overlap is common due to breed standards allowing some variation. Temperamentally, males and females share similar traits, though individual personality differences may occur. Both genders require equal mental and physical stimulation.