The news that a homesick sheepdog made a 380km walk home has recalled previous remarkable canine journeys.
Pero travelled to his birthplace in Wales after leaving his new home in Cumbria.
In a story that echoes the classic story Lassie Come Home, the 4-year-old working dog is thought to have returned to the village of Penrhyncoch, Ceredigion by foot 12 days after escaping from his new owners in Cockermouth.
Tales abound of dogs' incredible loyalty and ability to track down their owners, from the fictional Lassie to the real life Greyfriars Bobby who is said to have spent 14 years guarding the grave of his former owner.
Nick Jones of Alpha Dog Behaviour said while "240 miles (380km) is in the realm of the fantastic", there were examples of dogs having made such journeys.
Legendary hounds include Bobbie the Wonder Dog, said to have made a journey of over 2500 miles (4020km) from Indiana to Oregon in 1924 six months after becoming separated from his owners on a road trip.
More recently, 3-year-old black Labrador Bucky reportedly astonished his owner Mark Vessels by travelling 800km from Winchester, Virginia to Myrte Beach, South Carolina, where Vessels had moved for work in 2012.
Last year it was claimed a dog injured in a hit-and-run accident in Russia walked nearly 320km just to find the woman who had nursed him back to health.
For most dogs finding their way home even a few km away is too much of a challenge, but Stan Rawlinson, a dog behaviourist said some dogs, especially working dogs, have an "amazing spatial memory" and "some sort of tracking mechanism to where they live".
He added: "How homing pigeons do it is they work on the magnetism in the earth, which is how we use compasses, so it's almost like a spatial compass they have in their head, and it is believed dogs could have the same thing."
For a sheepdog, 32km a day would be "very do-able", Rawlinson said.
"A sheepdog is used to running round and herding sheep and doing 40, 50 miles in some places. They travel miles and miles in a day."
He added: "The bond between a shepherd and his sheepdog is very close. "It needs to get back to the person it feels totally secure with and that's how it gets that far."