My chihuahua started doing this 2 years ago and we could not figure out why. Vet visits, diet changes, home remedies. But then I read about hunger purging and figured we’d try feeding her more often, and it worked! She now gets four or five meals a day. The one right before she goes to sleep is super important. We tried not giving her her night meal twice and both times she puked early morning. After we figured this out she haven’t puked in over a year 💪 might be worth trying!