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Hello. Thanks for the question.
I think a fast is ok, but I would only do 8-12 hours. 24 is a little excessive. When feeding the next time, try to elevate his front feet off the ground. You can sit him up while you're in a chair or you can put his foot a few steps up on some stairs.
If he continues to regurgitate, then I would get some x-rays. In that case, I'd be worried about megaesophagus. This is where the esophagus doesn't contract down normally to move food to the stomach. It can be part of a nerve disorder (Myasthenia Gravis) or it can be idiopathic (unknown cause). If we don't find a cause, and we normally don't, feeding elevated is the best way to prevent this. There is something called a Bailey Chair that helps a lot with these dogs.
Here is a nice write up on the condition in dogs:
I hope this helps, let me know if you have any other questions.