Dear Laura:
 
>Yesterday I noticed that on the upper half of his belly, progresssing all
>the way up to his neck, is what looks like extensive bruising.
 
A picture would be very helpful, however, let me venture a guess -
 
I hear this not too uncommonly - ferrets turning blackish or bluish several
weeks after adrenal surgery.  In many cases, this is the follicles starting
to grow new hair.  Usually if there is brusing as a result of surgical
scomplications, it appears as tiny hemorrhages rather than one diffuse
bruise.
 
With kindest regards,
Bruce Williams, dVM
[Posted in FML issue 3317]