Pills all have to carry information stating if they carry any of the 14 main allergens. For example, when my DS3 gets older, if he took Piriton tablets to try to calm an allergic reaction, he could actually end up with a more severe anaphylaxis (to an antihistamine!) because it contains Lactose.
He is allergic to Cows Milk Protein in all it's forms, and in the minutest of traces.
I have to do extensive research on bloody mince before I feed it to him.
He currently hasn't had his MMR, despite being 21mo, on the advice of his Allergist, as we are unsure if it will provoke an allergic reaction like his second DTP did. He is too young to have been tested for all 14 major allergens, but he goes into anaphylaxis from CMP and Nuts, and is also highly allergic to soy.
I CAN understand medicines needing to be clearly labelled for even the minute chances of cross contamination of the 14 major allergens.
What I can't see is that labelling a medicine as vegetarian when vegetarianism is not a life threatening issue, is being entirely sensible.
And if we have Mad Cow disease, it'll be from the prion-riddled burgers we ate in the 80's, not from modern herds.