Dogs do not need to fast for deworming. When using oral deworming drugs, it is recommended to feed a small amount of food to prevent the deworming drug from irritating the dog's gastrointestinal tract and causing the dog to vomit. Internal deworming requires strict control of the dosage, and the appropriate dosage is selected according to the dog's weight, usually once a month.

Precautions for deworming dogs:

1. Take it at intervals. Internal anthelmintics need to be taken 3 hours before and after the dog eats. This can reduce the probability of the dog vomiting. The amount of anthelmintics should not be too much.

2. Regulate the intestines and stomach. If there are worms in the dog's body, diarrhea may occur after oral anthelmintic drugs. You need to pay more attention to the dog's condition, which can be improved with oral probiotics.

3. Take it again. Some anthelmintic drugs can cause gastrointestinal reactions and cause vomiting in dogs. If the dog vomits out the drug, he will need to take the drug again.

4. Pay attention to the medication cycle. The medication cycles for therapeutic deworming and preventive deworming are different. Generally, therapeutic deworming may require short-term continuous medication.