I took two pictures of the boil thing, it used to be round and white but then one day i came home and it was "popped". Im not sure if this could be a problem or maybe this could be treated at home without any needance of a vet. he is about 10-11 years old and bicshon frise.
You really should take you dog to the vet asap cause it might get infected
Call the vet if its not healing. his age is advanced and can't fight infections as he used to. it is infected for certain.