The two goats are about 30 lbs. and 50 lbs. My question, we bought Ivesco goat dewormer concentrate medicated. The active ingredient is MORANTEL TARTRATE 8,800 G/TON. Acording to directions it says 1/10 of a bag for each 100 lbs. Our problem since one is 20 lbs and the other one 50 lbs. how can we make sure each one gets the right amount? And can they be harmed if one get a little more than the other one. The small goat is not a picky eater and the bigger one is. This dewormer is the kind they eat.