Dear Sonya:
 
>I'm concerned (worried) about their exposure to the evaporating (copper)
>water.  Could inhaling this "copper water" be harmful?  Could it lead to
>respiratory infection/damage or to copper poisoning (Wilson's Disease...
 
Now that's a ferret-proofed house.
 
The risk from copper tubing is minimal - to my knowledge it has not been
incriminated in copper toxicosis in animals (certainly not Wilson's
disease), and only once in the human literature - a relatively sketchy
case report on three children.
 
Copper toxicosis in ferrets is rare, and like in dogs, a genetic metabolic
defect has been incriminated (although there are so few reports of copper
tox in ferrets that nothing definitive has been proven.)
 
I suppose that if it was kept out of their reach, and exposure was minimal
and occasional, you likely have little to worry about here.  However, if
you adhere to the zero risk principle - it;s back to the return line!
 
With kindest regards,
Bruce Williams, dVM
[Posted in FML issue 3281]