Lubricate well with K-Y or petroleum jelly and insert into rectum. Hold in place for 1 minute, remove and wipe clean with tissue. Read temperature and clean with rubbing alcohol. Vomiting Intermittent vomiting is usually not serious as the dog's natural reflexes cause periodic vomiting to totally empty the stomach of debris. Vomiting more than twice during a 12-hour period warrants a call to your vet.
Dogs commonly eat grass to force themselves to vomit.
A Reference for Dog Breeders and Owners by Karen J. Wolfsheimer, D.V.M., Ph.