My experience (and my vet, who sees a lot of ferrets and keeps up with
the latest chemo, etc.) has been that if the ferret is under two years
old, nothing helps, over two years old, some success.  I have had five
ferrets w- lympho, and that has been my experience - three at or under
age two, who all passed quickly (two were given aggressive treatment),
one about 4 yrs old, treated aggressively, who lived another 18 months,
and one 8 yrs old, treated only with pred who lived another 4 months.
Hope someone else has had better luck.
[Posted in FML issue 5262]