Will Falconer, DVM Moderator
When I said, "there are currently no letters…" above, I was speaking about the link you provided. There were no boilerplate letters for those entities.
And sure, holistic vets (or any open minded vet) will be able to write a waiver letter for more vaccines that should fly with all but the most stubborn of kennels, groomers, etc. I've been doing that for years for my clients.