Vets at the Blue Cross thought that a stray dog brought in needed pet medication as almost all of his hair had fallen out.
Dougal was found wandering around Ireland and was taken into the Lewknor adoption centre.
He was very thin and subdued, his remaining coat was matted and he was almost completely bald on his back and rear. The reason for his hair loss was investigated through a number of tests.
Animal welfare assistant Jess Hollis says: "We carried out lots of tests to find a cause for the hair loss but they all came back negative."
After Dougal was adopted his hair quickly started to grow back and he now has a full coat.
"Dougal now has a thick, full, glossy coat and obviously has a very close bond with his family. This story just goes to show how a little bit of TLC can make a whole lot of difference to a dog's life," she said.