While Heinz bodies can be seen in any species when enough onion is given,
and of course cats are predisposed to the development of Heinz bodies
(precipitated denatured hemoglobin on the RBC cell membranes) -
 
I have never seen Heinz bodies on a ferret blood smear, nor does the small
amount of onion powder in Gerber's baby food appear to cause any problem.
 
Ferrets do develop a immune-mediated hemolytic anemia, but right now,
little is definitively known about it, and it does not appear to be
associated with the feeding of baby food - it is most often seen in
preciously healthy animals.
 
With kindest regards,
Bruce H. Williams, DVM, DACVP
 
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[Posted in FML issue 3411]