My wife and I took down an old fence made of 1"x 4"x 8' lumber and some 4x4s when we moved into our house. Recently I was tasked with making a feeder for her goats and used some of it to make the feeder. I'm unsure if the wood is treated or not but assuming it possibly is. What would this cause if they ate pellets out of it?

I ask this because a couple weeks after we started feeding them in it some of the goats got sick with low temps, wouldn't eat/come out of the barn, and had diarrhea. We medicated with probios, 2 different wormers(Safeguard/Ivamec), and Sulmet. After a week or so they get better, and it seems like another goats takes their place. So almost all the goats have gone though it now.

We first assumed the cause was one of our goats had bottlejaw and almost didn't make it. It was soon after she got better that the others started having diarrhea and we firgured with the recent wet weather around it could be worms.

Could it have been something else?