I prefer when they give me advice about the dogs' health than when they are giving me health advice.
For the most part, I don't mind people making suggestions about the dogs I've learned some stuff along the way that I'd never have known if people hadn't suggested stuff. Other stuff was crazy and no I've never used it. Then again do to personal health issues I've gotten used to working around people who know someone who did X and it made them much better and won't leave you alone when you don't go along. Sometimes you have to get creative in what you tell them to get them to leave you alone if you can't out right avoid them.
I'm honest enough to admit I knew very little about dog chiro, massage, and certain nutrition issues that I got suggestions from a number of people associated with the dogs over the years that has proven to be very useful. I'd never have know to look if someone hadn't said have you thought to try... Sometimes people are ignorant about their audience. DH and I have a friend who is rather traditional about dog treatments. His dogs have had long and prosporous lives. He isn't comfortable talking about some of the stuff we do with the dogs so we don't say have you tried... When other family/friends have had issues I have said have you tried? It isn't my nature to approach strangers so I can't imagine going up to a stranger for much of anything. Discussing alternate dog treatments would be a bridge too far for me.