
Perhaps they should in an area where there has been outbreaks, probably would not need to where the herd effect had been well maintained and many owners would find the addition cost prohibitive.
I don't think we should forget that until a couple of years ago hundred of thousands, if not millions, of dogs were boostered every year for the full raft of diseases and yet only a tiny proportion of them experienced problems due to an intolerance or the possibility of already harbouring disease or whatever. Under that regime too, the antibodies in the system at the time of booster could be expected to be considerably higher than at the current 3 yearly protocols.
We none of us know in advance exactly where our individual dogs will fall in all this but what we can do is look at the probabilities or risk and benefit. Anyone not confident of working it out can look to the British Veterinary Association's policy as represented the majority view of the profession.