Kirkland cat food - question and warning

Does anyone here feed their cats Kirkland Premium dry cat food? For
those who don't know it's Costco's store brand. I've been feeding it
to the stray cats in addition to Cat Chow. I realize it's not the best
food but it's better than nothing which is the alternative. Anyway,
the last bag of the Kirkland food that I purchased seems to either be
rotten or they've changed the ingredients or something. After using
half of the bag I noticed the food smelled like sewage (the top half
didn't smell like that). I've kept the bag tightly closed and no
creatures have gotten into it. The cats refuse to eat this food which
is odd considering they're all starving pigs who'll eat anything. So I
figure something must be wrong with it. Does anyone know anything
about this or has this happened to you? I've been wondering if it's
been recalled but I can't find any info so I guess it hasn't. I'll see
if I can find a phone number to make a complaint. I just wanted to
know if anyone else has had this problem with this food. It seems like
over the past 6 months or so that all the Kirkland brand foods (pet
and human) has really gone down in quality.

Mike,
There are no Costos in my state, but I have heard they have a wonderful
return policy (even without a receipt). I'd try bringing back the bag.
Perhaps there was a problem with that batch/shipment.

Rene