I'm not sure exactly what is meant by using ACV instead. I do know that if it is a replacement for the parvo vaccine, there could be horrible consequences. This is not standard of care, is not supported by most vets, and is not scientifically proven. It seems to be based on anecdotal evidence which should be extensively questioned.
Even if we are talking about doing one year boosters and then using ACV in lieu of yearly vaccines, I'm not sure what the point would be. Dogs can get parvo even if vaccinated, but that is not common, So I trust that the vaccines that my dogs have received are protective and there are no further steps I need to take to stop them from getting the disease. And no, I don't vaccinate yearly...nor do I trust breeder given vaccines for many reasons.
And it is commonly transmitted from feces to mouth. ACv on the skin could not prevent this.
__________________ Crystal  , Ellie May (RIP)  , Rylee Finnegan  , and Gracie Boo🐶 |