Been a few years since I've had a litter, so bear with me! I don't want the debate on whether or not to booster to begin with if that's ok, that's a whole different can of worms. :-) Assuming that I usually do boost the dogs, is it generally thought best to hold off if you plan to mate the bitch - she's decided to come into season just when I'd made an appointment for the booster! I don't want to risk anything with a possible mating or litter, but I also don't want to find the vets saying she has to restart as if she was a puppy. Assuming my vague thought is right that you hold off, do I boost before the hopeful litter is born or wait until after they are weaned and gone?

I'm not sure about boosters and mating a bitch but I think you can usually run over by about 3 months before the vet says you must go through the puppy course again (Ive been late getting boosters done in the past due to forgetting!)

I always made sure mine were utd with their boosters BEFORE being mated.    Ditto with worming - but I wormed the bitch again when the puppies were 2 weeks old, when they had their first worming because if the pups had any worms, mum cleaning them up could mean she'd be reinfested.

Unless your bitch is way overdue with her boosters, there should be no question of 'starting over' with vaccination.   Don't let this happen!!!    You do realise that boosters are only needed now every 3 years, apart from for Lepto which does drop off during a 12 month period, and rabies where appropriate.

If she's not boostered before being mated, then you just have to trust she has enough natural immunity to pass on to her litter (?) - I'd certainly not booster until she was well off the litter, or during pregnancy.

I'd booster her at the start of her season, before being mated.

I agree with JG, do it BEFORE mating. I had the one problematic litter where the pups ended up just not normal -two are already dead by the age of 6, there's been serious behaviour issues etc -and that was the one and only litter where I mated the bitch one day, boostered the next and mated again the day after. Could be complete coincidence but I would never risk it again.

She started her season a bit early, and really I would have preferred to mate the older bitch who isn't due for a month, but the timing is just right to fit between family commitments with this one, so it's a slight change of plan from the original. So would it be ok to boost her now which will be the best part of a week before mating? She has never shown any problems whatsoever with the booster.

Yes, I'd go for it asap.

>but I think you can usually run over by about 3 months before the vet says you must go through the puppy course again

No dog over 12 weeks old that has been fully vaccinated, EVER needs a full puppy course again.  A booster is a  booster is a booster.

If you have given puppy vaccinations, no you should never have to start the course again.  You really do not need to vaccinate a dog again after puppy vaccinations.  If you are not sure she is covered get her vaccine checked by titre testing.  You might have to seek a vet out but it is better than chemicals being given that are not needed. Too many vaccinations are given to dogs.

Lucy DID say she did not want the debate on whether to booster or not.

Another here agreeing with JG.  I had a bitch have her booster on day 2 of her season.  She was mated on day 8 and day 10, had her litter with no problems.  In fact I was so pleased with the pups, I kept the litter for myself (breeders prerogative.)  :-)

All vets should now be working to the WSAVA Guidelines which say dogs should not receive core vaccinations more frequently than 3 years. If they are recommending annual vaccinations they are going against the leading experts in the field of immunology.
Have a look at your dogs vaccination card and see which product was used last time. Then go and have a look at the vaccination manufacturers website, recommendations for most of the vaccines commonly used are now 3 yearly for core vaccines. So if the vet is suggesting using the product more frequently they are also going against the manufactures instructions.
Immunity does not just run out 365 days after the last vaccination and research has shown that in most cases it last a minimum of 7 years and in many cases the lifetime of the dog. You cannot boost immunity, if your dog already has it, giving a vaccination is not like topping up fuel in your car.

Have a look at some of the articles written by Dr Shultz or Dr Jean Dobbs. They are the leading experts in the field. Dr Shultz was instrumental in producing the current WSAVA guidelines, which a lot of vets choose to ignore for purely economic reasons.
It is not in the bitches best interest to over vaccinate just before becoming pregnant as it could compromise her immune system and those of any puppies she subsequently carries.
If you would like any links to current scientific studies please PM me and I will be happy to supply them. 

No don't vaccinate, annual vaccinations for core diseases are no longer required and in fact over vaccination could be detrimental to the bitch and the subsequent litter.
See WSAVA Guidelines.
Also check which product was used last time and have a look at the manufactures website. Most of the vaccinations currently used are licensed for 3 years so if your vet is using them more frequently he is going against the manufacturers instructions as well as the WSAVA guidelines.

Have PM ed you
Diane