Yes, many people buy cute little fuzzy chicks because they are cute, but when they get older, they don't want the responsibility.
Same as when people get their children Easter bunnies. Our local shelter had so many rabbits surrendered this year, it was awful.
Anyway, if the girls have a heavy load of worms, they will not thrive. The worms take nutrients away from the bird; they are basically eating 90% of the chickens daily food intake.
Worms can be seen in their poops, as was the case with my girls. We treated them with Wazine for roundworms then used Ivermectin pour-on (5 drops per hen) for other worms and lice.
Egg withdrawal period is 14 days. Re-treat the chickens again in 2 weeks.
note: this method will not treat active gapeworm.