My dog is 2 now, last year I didn't pay much attention when he had his routine vacs, but this time checked product info online to see what was due. He had Nobivac Lepto 2 and Nobivac DHP last year.
Info said said DHP should be given 3 yearly and Lepto 2 every year, so should only be due Lepto 2 this time.
Went in to have vac, saw vet had 2 vials so asked what he was giving - DHP and Lepto 2 - I said I understood DHP only needed to be given 3 yrly and would he mind checking the package insert. He said he'd speak to a colleague.
Came back a few minutes later and said I was right, the manufacturers recommend it be given 3 yearly but I should consider having it done today as Parvo was a very dangerous disease 
. I said I'd rather follow the manufacturers guidelines and my dog was given the Lepto.
When I went to pay the receptionist looked confused and said "only one vaccine's been given, that can't be right, they always have more than one". So it seems it wasn't just this particular vet getting confused but a general policy.
I work in child health and manufacturers guidelines for vacs are always followed. If immunity has been shown to last 3 years it's pointless giving a vaccine every year and could increase risk of side effects.
I don't understand why a vet would advise this, surely it can't just be because they want the money?