Da Vinci may well have a gastric ulcer, or problem with kidney/liver. Please take him to a qualified vet for a check up!!! The nodes in the neck will swell if there is a heliobacter overgrowth which sometimes accompanies ulcer conditions. Only antibiotics will help in this manner.... also have the pred dose checked-- pred can effect the organs-- and may also be prompting the bad breath-- A very interesting note i found recently is that the FDA did agree about ethoxyquin being too high ( and that tests concluded in a canine study) it was harmful-- therefore they called for a reduction from 150 parts to 75 parts. Now this is from a study which showed hepatic livers and liver conditions--. How do you feel about your ferrets diet now???? Iams contains ethoxyquin-- and it may be a source of the numerous problems we see posted on the FML of ferrets with liver disease. I am not a scientist, but all fur clothed critters be it canines or ferrets bodies funbction in a similar manner-- if it has been deemed harmful to dogs, it also must be to others. Just a cautionary word, no I am not a scientist-- but I do significant research. Alicia a shelter MOm [Posted in FML issue 2125]