This is just my opinion, but part of zimectrin gold is ivermectin, which apparently has been losing it’s effectiveness on most chicken worms. I would get something else to treat most other chicken worms, such as Valbazen or SafeGuard liquid goat wormer or horse paste. The other ingredient in Zgold is praziquantel which treats tapeworms. If you need to treat for tapeworms, Equimax is less expensive than Z Gold and has twice as much praziquantel. Dosage is 0.03 ml per pound—0.15 for a 5 pound chicken.
So to really answer the question, I would use Valbazen or SafeGuard for most worms, and Equimax for tapes only.