I know it's pretty common for cats to not chew dry food and to throw
it back up, but this is getting ridiculous.  For the past 3 nights in
a row, my cat has started retching really bad.  The other night it
went on for 3 hours.  I half-suspect it's not the not chewing, as I
see whole pieces of food in it, but I'm beginning to wonder... the
last time I had a cat with an issue like this, he was dying of
leukemia.  Should I worry?

P.S.  He's going to the vet on Monday.  I'll will update on what I
find out.

- Winter