The breeder isn't entirely incorrect, although overvaccination is more likely to provoke allergic reaction and autoimmune disease than to weaken the immune system. Overvaccination has been recognised as an issue as understanding of duration of immunity has increased. Annual vaccinations certainly used to be recommended, but now a lot of vets are aware that an every-year-every-component vaccination is unnecessary at best, and are moving to more flexible vaccinations schedules. To the best of my knowledge, rabies and distemperare now recognised to have an immunity duration of at least three years, and in many dogs more, and canine adenovirus Type I and Type II immunities seem to last around seven years. Parvo immunity may be lifelong after the first booster shot. Our local vet is using a three-year interval for all those vaccinations now, and I understand many other vets are beginning to move to a three-year schedule as well without seeing any increase in disease. If your vet expresses discomfort with this idea, he should look up the work by Ronald Schultz at the University of Wisconsin-Madison School of Veterinary Medicine, and I believe there is something on vaccination practice in Kirk's Current Therapy XII. However, an annual physical exam simply to check for things like heartworm, tumors or tooth health isn't a bad idea at all.

And who IS this friend??? What are his credentials???

It's true. There is too much and too often, of vaccines being given. In 1998, the research started coming out that it actually can endanger the pets to be vaccinated often or even more than once in some cases. For many years we have been using titers as a judge to tell use if we should vaccinate again. It's a way of measuring what your pets' immunity level is to a certain disease and doing lesser things instead of a regular vaccine. Other than the required rabies, we've never had to revaccinate our dogs after their initial shots. And then earlier this year I read this report which really shocked me. Please read it and consider whether to vaccinate and how often you will. It's called The Science of Vaccine Damage http://www.dogsadversereactions.com/scienceVaccineDamage.html