Mark Taylor / Black and white Jack-a-poo, Jack Russell cross Poodle, pup, 8 weeks old, jumping up.

Florian Möllers / 'Jogi', a Jack Russell Terrier cross breed, male playing in the snow. Germany

Yves Lanceau / Dog, Jack Russell Terrier, three puppies with pumpkin

Jane Burton / Two smooth coated Jack Russell Terrier puppies, tan and white, 6 weeks,

Mark Taylor / Smooth coated Jack Russell Terrier puppy, black and white, 9 weeks, sitting, looking up

Jane Burton / Two Rough coated Jack Russell Terrier puppies playing with boot lace

Jane Burton / Rough coated Jack Russell Terrier puppy, black and tan, portrait

Jane Burton / Rough coated Jack Russell Terrier puppy, black, tan and white, portrait

Jane Burton / Rough coated Jack Russell Terrier puppy, tan and white, with a boot

Jane Burton / Smooth coated Jack Russell Terrier, black, tan and white, female with two 8 week puppies

Mark Taylor / Rough coated Jack Russell Terrier, tan and white, lying down, panting

Jane Burton / Smooth coated Jack Russell Terrier, white, looking up, standing on back legs

Ernie Janes / Jack russell terrier puppy resting on hiking boots

Ernie Janes / Jack russell terrier in box with Christmas tree

Ernie Janes / Jack russell terrier in wheelbarrow with apples, UK

Mark Taylor / Blue-and-white Jack Russell Terrier puppy, Scamp, wearing a party hat.

Petra Wegner / Jack Russell Terrier, puppy bitch, 4 month, sitting with back legs splayed

Jane Burton / Jack Russell Terrier puppy

Mark Raycroft / Jack Russell or Parson Terrier (Canis familiaris) adult jumping through agility tire

Pascal Pittorino / Jack Russel Terrier in garden, Provence,Var, France, July

Mark Taylor / RF - Two Jack Russell x Border Terrier puppies, sitting. (This image may be licensed either as rights managed or royalty free.)

Mark Taylor / RF - Five Jack Russell x Border Terrier puppies, sitting. (This image may be licensed either as rights managed or royalty free.)

Mark Taylor / RF - Chocolate-and-white Jack Russell Terrier. (This image may be licensed either as rights managed or royalty free.)

Mark Taylor / Brown Jack Russell x Border Terrier puppy, sitting.

Mark Taylor / Brown Jack Russell x Border Terrier puppy, standing with paw raised.

Aflo / Jack Russell terrier puppy indoors with bow tie.

TJ Rich / Jack Russell Terrier sitting, rescue dog, Wiltshire, UK

TJ Rich / Jack Russell Terrier, Wiltshire, UK

TJ Rich / Jack Russell Terrier running with ball. Wiltshire, UK

TJ Rich / Jack Russell Terrier listening to owner, rescue dog, Wiltshire, UK

TJ Rich / Jack Russell terrier shaking paws with owner, rescue dog, Wiltshire, UK

TJ Rich / Jack Russell terrier on lap of owner, rescue dog, Wiltshire, UK

Mark Taylor / Jack Russell Terrier puppy, Bertie, age 11 weeks, sitting and looking up.

Mark Taylor / Jack Russell Terrier puppy, Bertie, 11 weeks, sitting.

Mark Taylor / Jack Russell Terrier puppy, Bertie, 11 weeks, standing.

Mark Taylor / Jack Russell Terrier puppy, Bertie, 11 weeks.

Mark Taylor / Jack Russell Terrier puppy walking and licking her nose.

Mark Taylor / Jack Russell Terrier puppy sitting.

Mark Taylor / Jack Russell Terrier puppy.

Mark Taylor / Jack Russell Terrier puppy walking.

Mark Taylor / Jack Russell Terrier puppy sitting and looking up.

Klein & Hubert / Jack Russell Terrier puppy trying to lick kitten on old wheelbarrow.

Klein & Hubert / Jack Russell Terrier puppy licking kitten on old wheelbarrow.

Klein & Hubert / Sleeping Jack Russell Terrier puppy and kitten on old wheelbarrow

Klein & Hubert / Two Jack Russell Terrier puppies and tabby and white kitten in old cart

Klein & Hubert / Jack Russell Terrier puppy sleeping on old wheelbarrow

Klein & Hubert / Two Jack Russell Terrier puppies and tabby and white kitten in old cart

Klein & Hubert / Jack Russell Terrier puppy trying to lick kitten on old wheelbarrow.