I've had a healthy, happy flock all summer, with no issues. A month ago, though, I saw our secondary rooster poop out a worm. We have never wormed our flock. We spent a week following chickens around looking at poop, but saw only 1 more instance of wormy poop. But we decided to worm them with Wazine17. Last Sunday was the first dose. My flock is split into 2 coops. All the adults, laying hens and mature roosters, including 8 or 9 birds that haven't matured are in the main coop/run. The other coop is a grow pen that currently has a mixture of Polish and pullets that we received from a hatchery in 2 shipments during May. The main coop has had no issues or reactions. However, the small coop has had 2 deaths in 4 days. The first was 4 days ago, a Polish, who was acting fine the day prior and then just got really weak. We moved it inside, dosed it with Tylan50, and it was dead the next morning. Today, when I opened the coop there was another Polish laying on it's side. I thought it was dead, but it was still alive, though barely. It was chilly this morning, so I laid it in the sun. About an hour later, it was sitting in the grass with it's head up, but hadn't moved from it's spot. I had time to better inspect it. What I found was a mound of poop on it's vent. It wasn't hard, but covering the entire vent area. I sprayed it off, and found the vent open to almost the size of a quarter, with more poop at the ready to come out. I say poop, and this might be important, but it wasn't really poop. It was mostly undigested food, including corn and feed. I thought that there might be a serious blockage, so I gave it's vent area a little squeeze, and about 4 normal poop sized worth of this undigested mixture came out. It was a lot. 5 minutes later it died. I'm totally clueless as to what happened here. There were no signs of illness or CRD, like sneezing or rattling or anything else. One minute they are fine, the next, they are close to death. All within days of being dosed with Wazine. So, I guess my question is whether or not anyone has ever had chickens have a bad reaction to Wazine, and does this sound like it could have been from the Wazine? As far as dosing, both flocks got 1 oz Wazine to 1 gallon water, for a day, and then emptied at night and given fresh water for 10 days. I plan on dosing again tomorrow, but I'm a little leery because of the 2 that died. Any opinions would be greatly appreciated!