If I bought a horse that has records for vaccines several years ago but nothing since, do I need to vaccinate as if he has never had vaccines (ie. initial dose and then second dose 4-6 weeks later, then annually after that)?
I am assuming I would as it's not even close to annual if the last one was about 3 years ago, but I just wanted to make sure.
"Be the change you want to see in the world."
In most cases even several years without regular vaccinations still leaves the animal with "memory" of the antigen, and a regular course of vaccination is sufficient to keep the immunity level up to snuff. You could even say that single yearly vaccinations ARE "boosters", really, unless you are using something where the strain is updated yearly, like with human flu shots.