A forlorn-looking hound is winning hearts and sympathy across the Internet after its owner abandoned him at a railway station with a suitcase full of its belongings.

The sharpei crossbreed dog is thought to be two or three years old and was left tied to a railing at Ayr railway station in Scotland on Friday with a suitcase that included a pillow, a toy, a food bowl and food.

His story started trending after the Scottish Society for the Prevention of Cruelty to Animals posted a picture of him on its Facebook page on Tuesday afternoon.

"The 2-3-year-old Shar-Pei cross is microchipped and we were able to find out his name is Kai," the charity said.

"We contacted the owner registered to the microchip, who stated they had sold him on Gumtree in 2013. Unfortunately they could not tell us the address of the person who bought him."

Gumtree is a free classified adverts website.

Says the SPCA: "This case highlights the potential consequences of selling an animal online as it often leads to the impulse buying of pets that people know very little about.

"Regardless of the fact Kai was left with his belongings, this was still a cruel incident and we are keen to identify the person responsible. If anyone can help we would ask them to get in touch as soon as possible.

"Kai is around two to three years old and is a lovely dog with a nice nature. We will look after him until we can find him a permanent and loving home."

Said Ms Kristine Coma on Buzzfeed: "Seeing him sitting there with his suitcase.. I'm definitely crying in my office. This is so cruel! If you are not able to properly care for a dog, that you wind up selling it online, don't get a dog in the first place."

"Why do people even do this? People should look at pets as an extension of their family... not something that can be disposed of," said another poster.