I'm pretty sure the only legally required vaccine is Rabies in the US and I think also in Canada (please correct me if needed).
That said there are Core Vaccines (Rabies is one of those) which most vets will, with good reason, want to give your pup. These include Distemper, Parvo and others.
The next level is called Non-Core Vaccines. These are sometimes called Lifestyle Vaccines. These include Lyme, Leptospirosis and others. Sometimes, due to geographic movement of the means of transmission, or change in lifestyle, these may shift to Core status.
(Naturally, I'll add some links lol.)
Research is showing that many/most of these vaccines remain effective beyond the old 1 year legal re-vaccination requirement (after the original and booster series), and many places will now accept a 3 year Rabies vac because of that.
Titering to check antibody levels is gaining ground in place of simply re-vaccinating yearly (or a longer interval) for non-Rabies vaccines but there is still discussion, not about validity in itself, but testing guidelines.
Core/Non-Core
Canine vaccination recommendations for general practice.
www.aaha.org
Vaccination Guidelines for Dogs and Cats How we can help Call 530-752-1393 to schedule an appointment with the Internal Medicine Service. Visit the Internal Medicine Service website Introduction The UC Davis veterinary hospital vaccination guidelines below have been based on...
www.vetmed.ucdavis.edu
Titering