Acid reflux?

Good day po. I have a three shih tzu. Nagpalit po ako ng brand ng dog food nila nito lang nakaraan, I mixed it with their old dog food. However, one of my dog kept vomiting. Kahapon po ay yellow yung vomit nya at ngayon po ay white na medyo mabula. I think she might be having an acid reflux. What can I do? Anyone here experience the same thing with their dogs? Thank you po!