I've found that a lot of pets don't like stainless steel, especially for water bowls. Ditto plastic.
Jamie has us trained: water has to be in onion soup bowls or a flat, wide pyrex dish, cat milk in china rice bowls, canned food on glass salad dishes, and dry food in china cat food bowls. It drives hubby spare when he's responsible for feeding every August!
Then again, our last dog ate and drank out of stainless steel pots. We started using them because he was tipping his bowls.
My parents used to have a cat who would only drink out of the toilet
or the dogs' water bowls, which were actually plastic buckets. Ginger would balance on the rim to drink, and ignore her own water bowls. The only food dishes she liked were china airline "dishes" that my mom had picked up at a factory outlet decades before.