What a horrible thing to say to you! You were trying to do your best for him. On saying that, I think many dogs die far earlier than they should because of all the harsh chemicals pumped into them through vaccinations, collars, and parasite treatments, (not to mention what they're exposed to in gardens). It's a huge industry and money is the top concern, not pets.
It enrages me that in Australia we're still advised that dogs need annual vaccinations, when much evidence proves that a single shot for parvo can last a lifetime. My dog only got a few vaccinations, and occasional heartworm treatments in summer. We also tried to limit his exposure to weed killer etc because I don't believe these products claims of being 'pet friendly.' He lived to almost 18 in excellent health until the last 6 months and I believe this is due to limiting his exposure to chemicals.