Norbert Wu / Sam and Ange walking each other, Golden and Yellow Labrador Retriever (Canis familiaris) mix, Carmel, California

John Beatty / 2020VISION / Two friends walking dog on moorland track.

Florian Möllers / Dog (Canis familiaris) and puppy on a walk. Zhouzhi Nature Reserve, Shaanxi, China, October.

Peter Cairns / A man feeds Mute Swans (Cygnus olor) - a juvenile with drab plumage and an adult - while people walk their west highland terriers. Fife, Scotland, November.

Ernie Janes / Three people taking English Springer Spaniel and terrier for a walk, spaniel in harness walking on backlegs, UK, September 2009

Mark Raycroft / German Shorthaired Pointer (Canis familiaris) walking

Petra Wegner / Girl training Cavalier King Charles Spaniel to walk to heel, tricolour

Aflo / ic-04507 Child taking Golden retriever puppy for walk.

Aflo / ic-04504 Girl taking dog for walk on lead.

Aflo / ic-04404 Child taking Golden retriever puppy for walk.

Suzi Eszterhas / African Wild Dog (Lycaon pictus) walking, Okavango Delta, Botswana

Mitsuaki Iwago / Kishu Inu (Canis familiaris) in the snow

Jane Burton / Owner, drying a front paw of her German Shepard Dog / Alsatian, 11 years old, after a walk

Jane Burton / Agility competition: Jack Russell Terrier walking along the dog walk in the Mini Class

Jane Burton / Golden Retriever bitch sitting down and carrying her lead, begging a walk

Pete Oxford / African Wild Dog (Lycaon pictus) pack walking together, endangered, Africa

Mark Raycroft / Soft Coated Wheaten Terrier (Canis familiaris) girl taking pair for a walk

Mark Raycroft / Bloodhound (Canis familiaris) walking through grass

Mark Raycroft / Border Collie (Canis familiaris) in mid-stride, fall

Mark Raycroft / Border Collie (Canis familiaris) adult laying on brick walk

Mark Raycroft / Black Labrador Retriever (Canis familiaris) on a walk with its owner

Mark Raycroft / Yellow Labrador Retriever (Canis familiaris) adult playing in park

Mark Raycroft / Golden Retriever (Canis familiaris) woman walking three adult dogs in grassy field

Mark Raycroft / Golden Retriever (Canis familiaris) woman walking three adult dogs in grassy field

Mark Raycroft / Miniature Smooth Dachshund (Canis familiaris) puppy wading in shallow water

Gerry Ellis / African Wild Dog (Lycaon pictus) male with tracking collar, Moremi Wildlife Reserve, Botswana

Mark Raycroft / West Highland White Terrier (Canis familiaris) walking on bridge

Mark Raycroft / Vizsla (Canis familiaris) puppy

Onne van der Wal / Mother helping young child to walk towards the sea with a dog behind them. Model released.

Richard Du Toit / Fisherman and dog walking on beach, Cape Agulhas, South Africa

Richard Du Toit / African Wild Dog (Lycaon pictus) pack on the hunt, Moremi Game Reserve, Botswana

Petra Wegner / Cavalier King Charles Spaniel, puppy, black-and-tan, 6 weeks, learning to walk on lead

Petra Wegner / Cavalier King Charles Spaniel, puppy, black-and-tan, 6 weeks, learning to walk on lead

Petra Wegner / Cavalier King Charles Spaniel, three puppies, 6 weeks, learning to walk on lead

Petra Wegner / Woman and Cavalier King Charles Spaniel, black-and-tan, entering home after walk in the rain.

Mitsuaki Iwago / Domestic Dog (Canis familiaris) with security guard

Pete Oxford / African Wild Dog (Lycaon pictus) pair running, endangered, Africa

Pete Oxford / African Wild Dog (Lycaon pictus) pack walking together, endangered, Africa

Heidi & Hans-Juergen Koch / Domestic Dog (Canis familiaris) walking alone on the beach in the evening, Monte Gordo, Algarve, Portugal