Id just like to say hes recovered now. I took him to the vets a bunch of times as he continued to loose weight and the vets extensively examined him with xrays and tubes down his throat and couldn't find anything obviously wrong with him so they said to carry on syringe feeding him. a few weeks later he passed a white runny stool and ever since then his green colour has returned and hes started gaining weight, so im not sure what was ever wrong. i think the green spots are a reaction to stress or some kind of illness but im not cetrain.