i rotate between three different kind of wormers. As different wormers kill differnt types of worms. zMost of the year o go between ivermectin and safegaurd. Then in the middle of the summer and after everyone kids they get eith valbazen or ivermectin injectable. Both can not be used on pregnant does. they are both really expensive but a little goes a long ways. I split it with another goat friend of mine. mainly use these kinds because they get round worms. ivermectin injectable is also good for liver flukes.