I usually use my weight circles to get the vet checks. I usually have enough to pay for at least part of the annual shots, etc. for my crew. There is a space at the bottom of the weight circle form that you fill in with the vet's info and they issue the checks made out to the vet. I haven't used them for food in a while. I also have a couple of nice jackets that I've gotten with the weight circles.
I do believe that there is a different form for cat food and you have to fill in another membership application. I have a cat food membership but I haven't sent in any weight circles. Maybe I'll do that over Thanksgiving.