I have a problem with my dog.?

I have a Jack Russell Terrier and lately she has been throwing up her food right after she swallows it. I can see that the food is still whole. I recently switched her food to Beneful by Purina. Before she used to eat another brand and I wasn't having the problem that I am having with her now. What can be some of the causes? Should I switch back to the other brand? Thank you for your help everyone.