A probe has been launched after a badly injured dog had to be put to sleep after being abandoned next to a Scots road.The Scottish SPCA is appealing for information after the stray border collie was found in a layby on the B1377 from East Linton to North Berwick on May 13.The male dog had collapsed and was suffering from a painful wound to his back end which had become infected with maggots.He was rushed to a nearby vet but due to his level of suffering and poor condition, the heartbreaking decision was made to put him to sleep.Scottish SPCA inspector Emma Phillips said “The male dog was found collapsed with a wound to his back end.“He had fly strike and a maggot infestation in the open wound.“We immediately took him for veterinary