Dog Vaccination Schedule by Age

Why Vaccination Schedules Matter

Dogs are susceptible to a range of serious, often fatal, infectious diseases. A well-structured vaccination schedule ensures your dog builds and maintains immunity at each stage of life. Vaccines work by training the immune system to recognize and neutralize pathogens before a real infection takes hold. Missing a scheduled vaccine — or giving it too early — can leave dangerous gaps in protection.

Veterinary organizations including the American Animal Hospital Association (AAHA) publish core vaccine guidelines that form the backbone of every reputable dog vaccination schedule. Your individual vet may adjust timing based on your dog's health status, lifestyle, and local disease risk. Use the schedule below as a starting framework, then confirm specifics at your next visit.

You can book a vet appointment at Happy Paws to get a personalized vaccine plan for your dog, or find a clinic near you for convenience.

Core Vaccines: Every Dog Needs These

Core vaccines protect against diseases that are widespread, highly contagious, or pose a risk to human health. The AAHA designates the following as core for all dogs regardless of lifestyle:

• Distemper (CDV): attacks the nervous, respiratory, and digestive systems; often fatal.
• Adenovirus / Hepatitis (CAV-2): causes infectious canine hepatitis and respiratory disease.
• Parvovirus (CPV-2): highly contagious gastrointestinal disease with a high mortality rate in puppies.
• Rabies: fatal neurological disease, legally required in most jurisdictions.

The first three are typically delivered together in a combination vaccine often called DA2PP or DHPP. Rabies is always given as a separate injection.

The Standard Schedule by Age

Here is the standard schedule your vet will follow:

• 6–8 weeks: First DA2PP combination (distemper, adenovirus, parvovirus, parainfluenza). Bordetella (kennel cough) may also be given here.
• 10–12 weeks: Second DA2PP booster. Leptospirosis vaccine first dose (in at-risk dogs). Lyme first dose if in a tick-endemic area.
• 14–16 weeks: Third DA2PP booster. First rabies vaccine. Second leptospirosis dose. Second Lyme dose if started.
• 12–16 months: DA2PP booster one year after the final puppy dose. Rabies booster (1-year or 3-year label depending on product).
• Every 1–3 years (adult): DA2PP (often every 3 years once adult immunity is confirmed). Rabies as required by local law. Annual non-core vaccines as needed.

Puppies need a series rather than a single shot because maternal antibodies — passed through the mother's milk — can interfere with vaccine response. The series ensures that once maternal antibodies wane, at least one dose lands on a fully responsive immune system.

Non-Core Vaccines: Based on Lifestyle

Non-core vaccines are recommended only for dogs with specific risk factors:

• Bordetella (kennel cough): Recommended for any dog that visits groomers, dog parks, boarding facilities, or training classes.
• Leptospirosis: Recommended for dogs in rural areas, those that swim in natural water, or those exposed to wildlife.
• Lyme disease: Recommended in tick-endemic regions.
• Canine influenza (H3N2 / H3N8): Recommended for dogs in high-density social environments or traveling to shows.

Talk to your vet about which non-core vaccines make sense for your dog's daily environment. You can use the TailRounds AI Triage tool if you are unsure whether your dog's exposure risk warrants a specific vaccine.

Keeping Track of Your Dog's Vaccine Records

Vaccination history is required for boarding, grooming, travel, and sometimes even dog parks. Keep both physical and digital copies. The My Pets on TailRounds section lets you view and store vaccine records in one place, so you are never scrambling to find paperwork at the last minute.

If you adopted a dog with incomplete records, your vet can either restart the puppy series or order titer testing to see if existing immunity is already adequate. Either way, do not delay — most of the diseases these vaccines prevent can spread before you even realize your dog has been exposed.