Boundless energy, insatiable curiosity and a manic urge to play with other dogs means exposure to infectious disease is just part of being a young dog.
Many serious illnesses can be prevented by vaccination. Some of these diseases have a very poor response to treatment and some are potentially fatal - especially for very young animals - making the primary vaccination course essential for every puppy.
As long as the mother has been vaccinated, puppies receive natural protection against disease through Maternally Derived Antibodies (MDA) in the womb and more significantly shortly after birth from their mother's first milk (colostrum).
This maternal immunity declines quickly and by the time puppies are a few weeks old they start to become susceptible to disease and infection.
To ensure there is no gap between the maternal and the vaccine immunity, the initial part of a puppy's primary vaccination course should start no later than when the puppy is 6-8 weeks of age.
The concluding part of the primary vaccination course is usually given at the 10-12 week stage.
Vaccines work by introducing a tiny dose of the bacterium or virus to the immune system. The immune system then generates a protective response against that disease and remembers and activates that response whenever the disease is encountered in future.
That's why vets check that puppies are healthy when they are vaccinated, in order to ensure their immune systems can respond as expected.
The second part of the primary vaccination course is necessary because for some puppies the MDA may interfere with the efficacy of the initial vaccination.
Also, some vaccines for disease, like Leptospirosis, which can be fatal in dogs need both courses to deliver maximum immunity.
Your puppy should not be considered 'immune' until at least one week after the full primary vaccination course is complete.
Until this time, and while the vaccine takes full effect, your puppy should avoid contact with other dogs and places where other dogs may have been.
It is very important to maintain your puppy's protection. Some vaccines are now licensed to protect pets for up to three years against particular diseases. But for other diseases, again Leptospirosis for example, annual booster vaccination is essential as protection declines after 12 months.
Your vet will advise the best vaccination protocol to maintain the optimum protection for your pet while minimising the number of vaccine components needed.
Current veterinary best practice recommends vaccination against Canine Parvovirus, Canine Distemper (Hard Pad), Infectious Canine Hepatitis and Leptospirosis. For puppies going into kennels, vaccination against all of these is usually compulsory.
You may also have had your puppy vaccinated against one or more of the infectious agents that cause Kennel Cough such as Bordetella. Protection here is particularly useful if showing, boarding in kennels or for young dogs, attending training or obedience classes.
Your vet may have protected your puppy against Canine Coronavirus - a mild intestinal infection that may go unnoticed but can increase the severity of diseases caused by other viruses in puppies.
Keeping pets fully vaccinated not only safeguards them but also prevents the spread of those infectious diseases to other dogs.
Furthermore when breeding puppies, the mother can only pass on MDA to the puppies if she has been properly vaccinated with regular boosters and has immunity herself.
If you are unsure or concerned about any aspect of vaccination, always ask your veterinary practice. Your pet is their patient and they will recommend the appropriate preventive care programme.