The Marshall Farms Guarantee states that :
 
This warranty does not guarantee against colds, influena or any other
bacterial or viral disorder.  Also not covered are conditions caused by
parasites or other acquired diseases growths, tumors or cancers.  Any
medical or surgical expenses that fall under the Marshall Guarantee will be
reimbursed through the place of purchase and WILL NOT EXCEED THE ORIGINAL
PURCHASE PRICE OF YOUR PET.  (Emphasis mine).
 
The way I read this, if your ferret cost $100-$150, that is the maximum
reimbursement that the guarantee permits.  Most pet stores will offer to
'replace' your ferret with a new one.  Not much comfort, if you have
already bonded to the little fert.  I would not worry about invalidating
this guarantee--it is not worth much anyway.
 
Carol
[Posted in FML issue 3248]