Maybe I'm missing something but when I read your first post I took it as yall feed the dog once while it is in doggie day care. This would tell me the owner would then feed it again later at home. That's what I would do if I was in that situation. Is this not the case?
He was boarding so when he stayed with us (overnight for 3 days) we were instructed to feed him once at 6AM and to take away his water at 4PM. We were also given a bag of dirt to sprinkle over his food?