Here are some links that i found on pine causing repiratory problems in
ferrets...
 
Ten Tips to Help Keep Your Ferret Happy and Healthy - ... Do not use
cedar or pine chips as litter for the litter boxes or as bedding in the
cage.  These products may cause respiratory problems in ferrets.  ...
 
Frequently Asked Questions - ... No.  Cedar and pine chips will cause
respiratory problems in ferrets.  You should use a ferret specific
"pelleted" recycled paper litter in litter boxes.  ...
http://www.everythingferret.com/faq.htm
 
Potty Training Ferrets - ... 1.  Use a dust free litter like Scamp 99%
dust free clay, Feline Pine pellets, Pine Fresh pellets, Cat ... These
can cause respiratory problems over a ...
http://www.ferretcentral.org/for-others/litter.html
 
Billy...
[Posted in FML issue 4422]