Puggle Puke

Advice needed:

Mr. Puggle will puke a foamy yellow liquid, about 1-2TBSP worth. But he runs to his crate and pukes in there. He doesn't do it anywhere else. He does this every few days. We don't give him people food or change his feed. Is this a puggle thing? Does your puggle do this? Why does he only do it in his crate? Thanks for any feedback.

Jennifer-the lady that feeds Mr. Puggle