Well the dog's fever can be treated easily but you need to look at your dog's age. If you have a baby dog then I will not recommend you medicines like Panadol. It can be risky for puppies. However, if you have adult dog then give it Panadol. Check its temperature to know intensity of fever and treat that accordingly. Giving Aspirin is also a good way to reduce fever. Fever causes vomiting, in some cases. Treat fever. The vomiting will be gone automatically.
My dog is running a fever and vomit her food. She had puppies last Sunday ( 6 days ago). I did not check to see how high the fever was. Her nose is very dry and her eyes seem weak (barely open).