It is normal for dogs to vomit dog food after taking anthelmintic drugs. Because anthelmintic drugs are relatively irritating, they will cause certain irritation to the dog’s gastrointestinal tract, which can lead to vomiting, poor spirits, etc. The situation usually improves in about two days. It is best to fast for about four hours before giving deworming medicine to your dog. This will not easily cause the dog to vomit, and the deworming effect will be better.