Puppies are protected against many infectious diseases through compounds called antibodies, which they receive in the first few hours from their mother's milk (colostrum). Early vaccination is pointless because these antibodies prevent vaccines working properly. However, by about six weeks the immunity provided by the mother begins to wear off. Therefore, puppies should be given their first vaccination at about 6-8 weeks and then given a second vaccination at about 8 - 10 weeks. The last set of vaccinations should be given around 12 weeks. Once puppies are vaccinated they can mix with other dogs. Early socialisation is beneficially for development. Until your puppy has received all its injections (and for a few days after), it should not mix with other dogs unless you can be certain that they are fully vaccinated and free of disease.

Kittens are given their initial vaccinations when they are about 6-8 weeks of age, with the final booster being given no sooner than 12-16 weeks of age. For cats older than 16 weeks of age, two doses of vaccine are given 3-4 weeks apart. Thereafter, booster vaccinations are annually here in tropical climate with so many stray animals. In temperate countries or in areas with low risk of exposure, revaccination is suggested every 3 years.