The decision that determines when a pets vaccination schedule begins is often left up to the pet owner. Pet owners vaccinate pets to fight off bacterial and viral diseases, and generally, the origin or physical location of the pet will reflect on which immunizations are introduced shortly after birth, and those that will be booster shots that are given later in life. A veterinarian is able to define and regulate the dosages for each immunization and the immunization schedule that is perfect for each pet.

Pets that are obtained from a licensed breeder will come from a living environment that is more controlled and deemed safe from many diseases. The breeding practices will reduce the possibility of infectious diseases spreading because the bitch and dam are immunized on a schedule. The viral environment that surrounds a pet that was placed in an animal shelter shortly after birth offers a greater chance of pets being infected with all types of organisms and regular immunizations are often made part of the adoption agreement.

The immunization record should be included with all pet adoption contracts. A pet owner will be able to see if the puppy had received inoculations when they were 6 weeks old. If those inoculations were missed for some reason, then the immunization schedule will be disharmonious and the missed inoculations will have to be administered right away. The pet owner may have several pets to schedule for shots. They might find it necessary to stagger the inoculation schedule on each to make the care of pets more affordable, and more fitted to their financial needs.

Under normal conditions, a pet owner can expect to schedule dogs for inoculations when they are 6 weeks old, and again when they attain the age of 9 weeks. Booster shots are often administered again when the puppy attains the age of 12 weeks. The frequency of the inoculations can vary with the type of vaccine that is used and some pets, whose vaccinations met the required schedule at 6 weeks old can forego another round of immunizations until they attain the age of 16 weeks.

Some pet owners worry that the scheduling of vaccinations are too close. Some feel that the puppy will not need any vaccinations to fight diseases because they get certain antibodies from the parent. The concern for overdosing a puppy on vaccines of any type are unfounded, but pet owners must still be diligent about noticing any adverse reactions that pets get after they have received an inoculation. Booster shots are normally given on an annual basis, based on the date of the last shot date given of the vaccination series they were administered when they were mere puppies.

Some pet owners do not vaccinate their pets and will pay dearly for that decision. The Law requires every pet to be vaccinated against rabies and those that do not follow the Law may have to face penalties in court, and be subjected to lawsuits by any person who is bitten by the animal. The treatment for rabies in humans is quite painful. Treatment requires several injections over a certain period and the injection site is the person's abdomen. A dog might lose their life because the pet owner did not immunize them. Pet euthanasia is common because it is the only way the animal can be tested for rabies.