Most often you will find that your dog is vomiting. In this situation do not panic. As dogs catch up out emotions fast and his situation might become worse. Therefore it is advisable to keep calm.
Fast your dog
Yes, fast your dog for eight hours. This might sound weird but it is true more you feed, more he vomits making him dehydrated. During this time do not give even water, but there is an exception to this. do not fast if your dog has become dehydrated.
How to know your dog dehydrated!!
Most often you dog becomes good if you fast your dog for eight hours. If not or you feel that dog is dehydrated to a vet nearby.