I had a problem about 3 weeks ago with one chicken who I suspected of having worms. They are almost 2 yo. She was drinking alot and not eating much, lethargic. I didn't have Valbazen but did have Wazine and Safeguard. I opted for Safeguard while I waited for the Valbazen to arrive. It took only about 4 days and the sick one showed signs of improvement. Her poop is normal - she has more pep, her drinking has returned to normal. I treated all of them a second time 10 days later with the Safeguard since the Valbazen had not arrived yet. Tomorrow is my 10th day again. I had planned to go ahead with another round of tx but this time with Valbazen. Now I'm wondering - since I've already done a full round of tx - do you think I should go ahead and use Valbazen now? Or should I just wait and use Valbazen the next time in 6 to 12 months? And do worms build up any resistance to these meds? And I want to Thank YOU for your previous help on this.