here's the funny thing - I have stedman's medical dictionary (27th ed, 2000) sitting right here in front of me on my lap, and it does NOT state what you have said. Stedman's is a MEDICAL (not veterinary) dictionary, and doesn't typically address dogs. I also have MVM in fromt of me, and it also does not state what you have quoted. MVM is not the bible on drugs - it is a brief overview of MEDICAL conditions, and doesn't mention a ton of drugs, PERIOD. in addition, the quote you have is talking about HUMANS, not animals. The "bible" on drugs is Plumb's and the Plumb's veterinary drug handbook does not have an entry for vitamin A. Your true sources? http://www.peteducation.com/article.cfm?cls=2&articleid=710 Please, leave out the half-truths.