But, they can live a long time and feel perfectly healthy...I had a cat
who lived eight years with the disease. I never thought about putting
him down until he came down full-blown with symptoms. It first appeared
like a URI with loss of appetite. The vet gave hime weekly shots after
those symptoms appeared -- I wish I could remember what it was, but
that was back in 1995. I think it was some kind of steroid but I could
be wrong. They helped boost his immune system and he overcame the first
bout of illness, and stayed healthy almost another year. Then another
bout of symptoms, that did not respond. He began to bloat and be
uncomfortable, and I had him euthanized then.
The #1 most important thing to keep a FeLeuk patient healthy is to
provide it a stress-free environment. We had an event that turned the
household upside down, and that's when he got sick.
Sherry

I beg to differ - at least where FL is concerned.  I have
lost two cats to the disease - the first I allowed to be
euthanized, but regretted it later.  Her grand-daughter
(with a more understanding vet) lived several ostensibly
"normal" and happy years after being diagnosed.  I have
never had any problem with having a cat "put to sleep" when
it was clearly suffering (I only wish we could do the same
for ourselves, when terminally ill).  However, FLV is not
ordinarily painful, except (possibly) in its final stages.
The cat will let you know when it's time - you just have to
be aware of it.