Height

The height of the terrier shall be between 8 and 12 inches as measured at the withers with the dog standing fully erect, with 10 to 12 being ideal.

Body

Sturdy, balanced terrier. Body length slightly longer than length of leg. Length should not exceed function. Straight back with high tail set carried erect. Chest should be spanned by two hands behind the shoulder blades. The rear should be well put together with strong muscle and good angulation. Well laid back shoulder.

Neck

Well laid into shoulder.

Head

Strong boned with powerful jaws and strong cheek muscles. Dark almond-shaped eyes, pigmented eye rims, dark black pigment on nose. Small, v-shaped ears carried close to the head. Prick, semi-prick and rose ears are acceptable.

Teeth

The points of the upper incisors slightly overlapping the lower. May be missing up to four teeth.

Legs

Straight as is consistent with the short legs for which we aim.

Feet

"Hound-Like", "Fox-Like" and "Hare-Like" are all acceptable. All three are considered sound working feet for a Jack Russell.

Gait

Free, lively, well-coordinated.

Coat

Smooth, rough or broken without coat being wooly. Smooth should not be sparse. Belly and underside coated.

Color

Predominantly white with tan, black or brown markings. Ticked or mottled acceptable. Brindle not acceptable.

Faults

Nervousness, cowardice, over-aggressiveness, week bite, unsound movement, minor physical deformities.

Disqualifications

Extreme viciousness, shyness or major physical deformities (these are considered such serious traits that dogs having them are not to be used for breeding.) Undershot or overshot bites, rye mouth.