Each week, our chief photographer Anita Ross Marshall chooses her favourite picture from the archives. She writes:

Friendship is one of the things that helps make the world go round. It comes in many forms and as a photographer  - you should not assume it only exists between humans.

Some of the best images I have ever taken have been because of those small but telling moments between us and, some say our best friend, the dog. 

The reason dogs are so good to photograph is they never hide their feelings, unlike some of us humans.

Image: Charity 5k dog walk for Stokenchurch Dog Rescue 

Camera Data: Canon EOS 1D Mark 3, Lens EF 70-200mm f/2.8 IS USM. Focal Length 90mm, Exposure 1/250th sec, f5.6, ISO 800