Booster vaccines for adult dogs
It's wise to have a titre (blood) test done to check levels of antibodies before repeating vaccinations. Puppy vaccines should last through to at least 3 years of age and may possibly last for life. Quote from VGG: Core vaccines should not be given more frequently than every three years after the twelve month booster injection following the puppy series, because the duration of immunity (DOI) is many years and may be up to the lifetime of the pet.
An annual health check is recommended, and that you should request titre (blood) testing before 'booster' vaccinations are given.
If this vaccine is considered necessary (the official stance is that lepto is now rare, and statistics show that usually only young working dogs who have never been vaccinated are susceptible) it should be given once yearly. The initial dose shouldn't be given with the puppy core vaccines - it should be started at 12-16 weeks, with the second dose 3-4 weeks later. Two types of lepto virus are covered.
The lepto vaccine can be very risky, especially for toy dogs - the greatest adverse reaction is acute anaphylaxis. Although your vet may offer a titre test for lepto vaccine, it can't actually be detected in a titre test as the bacteria are too small.
KENNELS AND VACCINATION REGULATIONS
Currently boarding kennels insist on proof of yearly boosters. Any kennels not aware of the new WSAVA regulations should be directed to the website.
THE PITFALLS OF OVER-VACCINATION
These hypersensitise the immune system, leading to sensitivity issues such as food intolerances, seizures etc.