bald spot developing on my drake's head?

[sunlotus]

My Beautiful Ganesha is going bald...I don't think its a mechanical thing, although perphaps he scrapes his head against the door jam as he goes in and out of the house (seems too infrequent to cause this though...don't you think?) is there any known condition which leads to this? or should I assume its the door being too low? thanks