Join Date: Apr 2008
Location: Orange County, NC
This is the info I found...
Moxidectin has been the subject of controversy and for good reason. It is the only horse wormer that is capable of killing the above larvae in a single dose, which is a very impressive feat. CAUTION: Its liability is that the overdose tolerance threshold is far less than other wormers; 5 times the standard dose can cause significant damage to your horse. Whereas it may be difficult to give an adult horse an overdose 5 times the standard dose, it's extremely easy to make this mistake when worming a foal. As such, at no time would I recommend using this wormer on foals or weakened horses.
The most popular Moxidectin-based wormer is Quest.
On the sixth day, God created the Quarter Horse.
On the seventh day, he Painted the good ones.