> I don't know any vet that would just give a booster after 17 months.
There is no scientific reason to give a dog with a mature immune system that has previously been vaccinated anything but a booster, whether the last one was a year, 3 years or 10 years earlier a booster is a booster is a booster.
In fact the vet in on of the dog papers wrote about this a year or so back and said this starting over again insisted on by many vets is tantamount to disgraceful conduct.
I also attended a seminar run by the South West Doberman club a few years ago, with a rep from Intervet present and this question was asked and the rep stated categorically that a booster was a booster and only one needed no matter how long since the last.
I have gone to my local vaccination clinic where they tried this on,a nd I argued it with them that I simply wanted a booster, yes I knew that the Lepto should have been yearly, but as it was a crap vaccine that didn't even give a years coverage, didn't cover the serovars most commonly found in the UK, and was the one most likely to cause issues, I would take my chances.
She gave up and gave me the booster as asked, I think one had been done three years earlier and another two.
I do the puppy vaccinations, the first booster, every 3 years and not at all once they are veterans.