Vaccination is the single highest-value thing you do for a dog’s health, and it is also the part of veterinary care people understand least. Here is the structure behind the schedule your vet hands you.
This is general information. Protocols vary by country, by region and by individual dog, and your vet’s plan reflects local disease risk in a way a website cannot.
Core versus non-core
**Core vaccines** are recommended for essentially every dog, everywhere, because the diseases are severe, widespread, or transmissible to people. In most of the world these are distemper, canine adenovirus (hepatitis), parvovirus, and — depending on the country — rabies.
**Non-core vaccines** are recommended based on lifestyle and geography: leptospirosis, kennel cough (Bordetella and parainfluenza), Lyme disease, canine influenza. A farm dog who swims in ponds and a flat-dwelling city dog do not need identical protection.
What the core vaccines actually prevent
**Parvovirus** attacks the gut lining and bone marrow of young dogs. It causes bloody diarrhoea, collapse and death, spreads through faeces, and survives in soil for months to years. Treatment means days of intensive care and it is not always successful. This is the disease the puppy series exists for.
**Distemper** is a virus that hits the respiratory system, gut and then the nervous system. Survivors are frequently left with permanent twitching or seizures.
**Adenovirus** causes infectious canine hepatitis, a severe liver disease.
**Rabies** is invariably fatal once symptoms appear, in dogs and in people. Where it is present, vaccination is usually a legal requirement rather than a choice.
Why puppies need a series, not one shot
This is the single most misunderstood thing about puppy vaccination.
A puppy takes in antibodies from its mother’s first milk. Those maternal antibodies protect the puppy for a few weeks — and they also block vaccines, because the puppy’s immune system never sees the vaccine long enough to respond to it.
The problem is that the antibodies fade at different ages in different puppies. In one puppy they are gone by eight weeks; in another they persist past fourteen. Nobody can tell which puppy is which without blood testing.
So the series exists to cover that unknown window. Doses are given every two to four weeks through the risk period, and the aim is to have at least one dose land after the maternal antibodies have gone.
A typical schedule
- **6 to 8 weeks:** first core dose, often given by the breeder
- **10 to 12 weeks:** second dose
- **14 to 16 weeks:** third dose — the important one
- **Rabies:** usually from 12 weeks, where applicable
- **6 to 12 months:** booster
- **Adult:** core boosters every three years is now common practice for distemper, adenovirus and parvovirus; leptospirosis and kennel cough are annual because immunity is shorter
Socialisation during the vaccination window
There is a real tension here: the window where puppies learn what is normal in the world closes at around twelve to sixteen weeks, which is before the course finishes.
The answer is not to keep the puppy indoors. Behavioural problems from under-socialisation kill more dogs than parvovirus does, through relinquishment and euthanasia for aggression. The answer is to socialise carefully:
- Carry the puppy outside to watch traffic, crowds, buses and bikes
- Visit clean private homes with healthy, vaccinated adult dogs
- Attend a properly run puppy class that requires proof of first vaccinations
- Avoid public parks, pavements heavily used by unknown dogs, pet shop floors and anywhere unvaccinated dogs toilet
Side effects
Mild and short-lived is normal: a day of being quiet, a sore lump at the injection site, mild fever, a reduced appetite. That is an immune system doing its job.
Contact your vet urgently for facial swelling, hives, repeated vomiting, difficulty breathing or collapse. True anaphylaxis is rare, happens within minutes to hours, and is treatable when caught quickly.
Titre testing
Blood titre testing measures existing antibodies and can tell you whether a dog is likely still protected against distemper, adenovirus and parvovirus. It is a reasonable option for adult dogs whose owners want to avoid unnecessary boosters. It does not work usefully for leptospirosis or kennel cough, and it does not satisfy legal rabies requirements.
