We also do a limited vaccine protocol as recommended by both our breeder and our holistic vet. Kea had her distemper/parvo combo protocol as a pup, rabies at 6 months, and we will be doing titers from here on out. The holistic vet believes she will not need another distemper/parvo combo until she is 6 or 7 (she's 2 now). We have never done bordatella, our breeder strongly advised against it, and after doing some of my own research, decided it wasn't worth the risks. We did have to take a letter to the doggie swimming pool from our vet saying Kea was healthy and we understood the risks, etc.
Regarding heartworm, our holistic vet recommended treating every other month instead of every month. She told me that during a veterinary conference back in the 80's when heartworm first reared its ugly head in Colorado, she learned that the heartworm parasite takes 90-120 days to mature. She raised her hand and asked why the preventative was to be given every 30 days, and was told that the 'average' pet owner is too STUPID to remember to give it every other month. Hmmm.
As I was researching all of this on my own after we got Kea, I came across a California breeder's website containing information about limited vaccination schedules as well as early spay/neuter that supported what my own breeder had told me. It looks like they're actually requiring their puppy people to agree to do titers... Preferred Vaccination Schedule
(I have no affiliation with this breeder but I really like the info they've included on their site)
I should also add that we have a conventional vet who we absolutely love in addition to the holistic vet. I think it's important to ask questions and seek answers from more than just one person. The field of veterinary medicine is constantly evolving, and not every vet will have had access to the same education in every area (vaccinations and nutrition are prime examples). I've found that this is the best way to stay on top of the latest advances to protect the health of my furbabies.