It may be less expensive to just go ahead and worm them with either Valbazen (more expensive, but fewer treatments,) or SafeGuard Liquid Goat Wormer 5 day treatment. Here is the cheapest and best value Valbazen 500 ml (1000 doses)
https://www.jefferspet.com/valbazen-oral-suspension-500ml-w-cap/p
Dosage is 1/2 ml given orally once and repeat in 10 days.
Most all farm stores including TSC carry the SafeGuard Liquid Goat Wormer. It is around $40, and the horse paste is cheaper for fewer chickens. Dosage is 1/4 ml per pound given for 5 days.
https://www.jefferspet.com/valbazen-oral-suspension-500ml-w-cap/p
Dosage is 1/2 ml given orally once and repeat in 10 days.
Most all farm stores including TSC carry the SafeGuard Liquid Goat Wormer. It is around $40, and the horse paste is cheaper for fewer chickens. Dosage is 1/4 ml per pound given for 5 days.