Id just call the vet and ask, we have a few animals that come into the clinic who have mild reactions to the drugs, the Doc normally gives a "pre" shot in the future before vacinating. But for the first reaction he normally prescribes a shot to ease the reaction..... though I dont really know the name or the amount. But I do know that you must be careful with medication after the reaction due to fact it can make it worse or even counteract the vaccine... so its best to just call your vet and ask their advice.... Always better safe than sorry! and most vets will chat on the phone with you and discuss what needs to be done, and if there is something that you can self prescribe most of the time the vet will direct you how to medicate your dog.