Do I need to worm again in 14 days?

[Chewie]

My vet gave me Fenbendazole to worm 36 chickens by mouth for 5 days. Do I need to worm them again in 14 days? She didn't say anything about that. If so , what should I use next? I've read posts that say I should use Wazine first. So confused.

 

[CoopCrazy]

Not sure but lets see if someone can help...