I have used ivmectrin as recommended once a month. I give each dog one tube safeguard( small tube) in three day period. 1/3 each dat for three days. Have done this ever since ivmectrin for dogs came in fashion. I never have a worm problem. You need to do it on schedule as close as possible. Use safeguard every 3 months.
Hunter, I think trained people drench medicine and de-wormers to cattle by putting the medicine down the animals throat using a hand held device. A drench gun or a balling gun. The medicine is not called drench but the method is called that. This medicine (wormer) can be drenched down the throat of some livestock....not dogs. Thanks for your reply.
Give minimum 1cc per 5lbs of body weight then add 2cc just on the safe side. Give it 3 to 5 days in a row. Then follow up in 2 weeks with another 3 days.