Thanks for the advice Judy... I have tried contacting numerous vets from Canada and the US and as yet (weeks) not heard anything back. Certainly if his condition stops improving or worsens a redoubled effort is called for.

The polysporin ointment has several antibiotic ingredients, and have greatly improved his appearance. My question regarding his bleaching colour was hinting at the possibility of a systemic infection... and still waiting to hear from anyone with experience on that. Otherwise, a topical ointment like polysporin and improved husbandry should be the cure.