Yesterday in Animal Science Techniques Lab we were giving dairy heifers vaccinations (Bo-Se, pinkeye, and clostridial), some IM some Sub-Q. One of the heifers (will be 2 this summer) went into anaphylactic shock about 15 minutes later. It was a really slow reaction but was very interesting to watch (probably the heifer wouldn't agree). She got really frothy, you could hear her struggling with her breath, and she fell over twice (drew blood). We gave her an epi shot and she ended up being fine but it was an interesting process! I am curious about how frequently adverse reactions actually occur as the result of vaccinations (nothing like this ever happened at home). Anybody have a similar experience?