Arthur the dog's tale of dogged determination
25 November 2014 Last updated at 13:49 GMT
A team of Swedish extreme adventurers on a 10-day race through the Amazon rainforest took pity on a stray dog and gave him some scraps of food.
The dog was so grateful, he started following them wherever they went - swimming rivers, climbing mountains and wading though knee-high mud.
Now the team have given him a name, Arthur, and have taken him home with them.
Richard Lister reports.