What happens if you drank water and oxytetracycline?

Fun question. So I have two animals who got sick. I did all my research and oxytetracycline (the powder you buy at the cattle feed store) could be used to help the issue.

Well. I made a bottle of the stuff and mixed it with plain raspberry tea (because I was told it was sour and animals wouldn't want to take the medicine).

I kept the left overs in a bottle that was wrapped in tinfoil in the fridge for the next day.

16 fl oz.... 2 table spoons of oxytetracycline mixed in.

Well. I went to refill the animals water and realized that someone must have chugged the whole thing because it was almost empty.

I am assuming the worst that could happen is a yeast infection from the antibiotics... but that's about it, should I be super concerned? No one is admitting to having drank it, but they also invited a bunch of friends over while I was at work. I don't believe my room mates would have done it. I told them what it was and not to touch it. But one is freaking out that his sleep-eating is starting up again.