Peter was a friend of mine and I do know he stopped putting vitimins in the drinking water a few years ago.Vetinary treatment is changing all the time as we gain knowledge,and Peter was the first to admit that treatments and drugs have to be constantly updated.A lot of Peters info is now out of date.I myself am always looking for better methods and trying alternatives.Peters research was second to none and the basics can still be trusted,and nothing he advised could do any harm.
I think instead of saying,one person says this and someone else says that,you have to know your own pig and do or use what your instinct tells you.Just remember that all info on the internet will quickly be updated.Having said that,a lot of the older meds are still the best.Ivermectin for instance has been used for years as a weapon against mites,and it is still the only efficient way to get rid of them.
I*f you think of it logically,vitimins lor meds in water are dangerous.You have no idea how much the piggy has drunk.,some pigs are big drinkers some hardly drink anything.In the case of meds they need to be given at the same time each day.Anything in drinking water is too hit and miss to be safe.
Peter also stopped using vits routinely quite a long time ago,.