Expert Summary
- The AAHA 2022 canine vaccination guidelines recommend starting core vaccines at 6–8 weeks, with boosters every 3–4 weeks until 16 weeks of age.
- Puppies need food formulated specifically for growth — not adult food — with a calcium-to-phosphorus ratio between 1.2:1 and 1.4:1 to support bone development.
- The socialization window closes at approximately 12–14 weeks, making early positive exposure to people, sounds, and environments the most time-sensitive task in a puppy's first months.
Getting your puppy's first year right matters more than any single decision you'll make as a dog owner. The habits, health foundations, and social experiences your puppy builds in months two through six shape their behavior and health for the next decade. This guide covers the actual timeline, real numbers, and evidence-based recommendations for vaccines, nutrition, and vet care.
The First 72 Hours: What to Do Immediately
Before anything else, schedule a vet exam within 48–72 hours of bringing your puppy home. Even if the breeder or shelter provided health records, an independent exam serves three purposes:
- Parasite check — roundworms and giardia are common in puppies even from reputable breeders
- Congenital condition screening — heart murmurs, cleft palates, and umbilical hernias need early identification
- Baseline record — establishes your puppy's initial weight, temperature, and health status with your own vet
Bring any paperwork from the breeder or shelter, including previous vaccine records and deworming history.
The AAHA 2022 Puppy Vaccine Schedule
The American Animal Hospital Association (AAHA) updated their canine vaccination guidelines in 2022. Here is the core schedule:
| Age | Core Vaccines | Notes |
|---|---|---|
| 6–8 weeks | DAP (distemper, adenovirus, parvovirus) | Start series |
| 10–12 weeks | DAP booster | 3–4 week interval |
| 14–16 weeks | DAP booster + Rabies | Final puppy series |
| 12–16 months | DAP booster + Rabies booster | Completes first-year series |
DAP (also called DHPP or DA2PP) covers distemper, adenovirus type 2, and parvovirus. This is the most critical combination for puppies — parvovirus kills unvaccinated puppies at a high rate, particularly in urban environments.
Rabies is required by law in all 50 US states. Most states accept vaccination at 12 weeks, but some require 16 weeks. Your vet will know your state's requirements.
Non-Core Vaccines to Discuss With Your Vet
| Vaccine | Recommended For |
|---|---|
| Bordetella (kennel cough) | Puppies attending daycare, training classes, boarding |
| Leptospirosis | Puppies with outdoor access, especially near water or wildlife |
| Lyme disease | Puppies in tick-endemic regions (Northeast, Midwest, Pacific Coast) |
| Canine influenza | Puppies in high-dog-density areas, boarding facilities |
Non-core vaccines are not optional if your puppy's lifestyle puts them at risk. Ask your vet to assess your specific situation.
Important note
Do not skip the 3–4 week booster intervals in the puppy series. Maternal antibodies from the mother can block early vaccines, so the series is designed to catch puppies at the right immunological window. One dose is not sufficient for parvovirus or distemper protection.
Source: AAHA Canine Vaccination Guidelines, 2022
The Socialization Window: Your Most Time-Sensitive Task
The primary socialization period for dogs closes between 12 and 14 weeks of age. During this window, experiences — people, sounds, surfaces, animals, environments — become normalized at a neurological level. After the window closes, novel stimuli are more likely to trigger fear responses.
What to expose your puppy to before 14 weeks:
- At least 100 different people (men, women, children, people wearing hats or uniforms)
- Loud sounds: traffic, thunder recordings, vacuum cleaners, construction
- Surfaces: grass, gravel, metal grates, stairs, slippery floors
- Other animals (healthy, vaccinated dogs and cats)
- Being handled: paws, ears, mouth, and body touched regularly (essential for future vet and grooming visits)
The Puppy Socialization Checklist published by the American Veterinary Society of Animal Behavior (AVSAB) recommends starting this process as early as 7–8 weeks, well before the vaccine series is complete. The risk of behavioral problems from under-socialization outweighs the marginal risk of disease in controlled environments.
Puppy Nutrition: What to Feed and How Much
Choose Food Formulated for Growth
Adult dog food does not meet the nutritional requirements of growing puppies. Look for one of these AAFCO statements on the label:
- "Formulated to meet the nutritional levels established by the AAFCO Dog Food Nutrient Profiles for growth"
- "For all life stages"
For large and giant breeds (expected adult weight over 50 lbs), choose food specifically labeled for large-breed puppies. These formulas have controlled calcium and calorie density to prevent too-rapid bone growth, which increases the risk of hip dysplasia and osteochondrosis.
Key Nutritional Targets for Puppies
| Nutrient | AAFCO Minimum for Growth | Why It Matters |
|---|---|---|
| Protein | 22% DM | Muscle and organ development |
| Fat | 8% DM | Brain development, energy |
| Calcium | 1.2% DM | Bone formation |
| Phosphorus | 1.0% DM | Bone formation |
| DHA (omega-3) | 0.05% DM | Brain and eye development |
Feeding Schedule by Age
- 8–12 weeks: 3–4 meals per day. Puppies have small stomachs and low blood sugar regulation.
- 3–6 months: 3 meals per day
- 6–12 months: 2 meals per day (transition to adult meal schedule)
Always use the feeding guide on the food package as a starting point, then adjust based on your puppy's body condition score. You should be able to feel — but not see — your puppy's ribs.
Expert tip
Overfeeding a puppy is more common than underfeeding. Rapid weight gain in large-breed puppies increases orthopedic disease risk more than almost any other controllable factor. Weigh your puppy monthly and track against breed-appropriate growth curves.
Source: Association for Pet Obesity Prevention, 2025
Deworming and Parasite Prevention
Most puppies are born with roundworms or contract them through their mother's milk. The standard deworming protocol recommended by the Companion Animal Parasite Council (CAPC):
- Deworm every 2 weeks from 2 weeks of age to 8 weeks of age
- Deworm monthly from 2 months to 6 months of age
- Begin heartworm prevention at 8 weeks (or as early as the product label allows)
Common puppy parasites and their symptoms:
| Parasite | Signs | Prevention |
|---|---|---|
| Roundworms | Pot belly, poor coat, vomiting | Pyrantel pamoate, regular deworming |
| Giardia | Soft/watery stool | Metronidazole, fenbendazole |
| Fleas | Scratching, flea dirt on skin | Monthly topical or oral prevention |
| Heartworm | No early symptoms (preventable only) | Monthly preventatives from 8 weeks |
Warning Signs That Require Immediate Vet Attention
Contact your vet immediately if your puppy shows any of these:
- Vomiting more than twice in 24 hours — can indicate parvovirus, ingested toxin, or intestinal obstruction
- Bloody or black stool — potential parvovirus or intestinal bleeding
- Lethargy combined with not eating — in puppies, hypoglycemia can become critical within hours
- Difficulty breathing, blue-tinged gums — emergency
- Seizures — emergency
- Pale gums — can indicate internal bleeding or severe anemia
Read our full Dog Nutrition Guide for life-stage feeding advice →
When should I take my puppy to the vet for the first time?
Schedule the first vet visit within 48–72 hours of bringing your puppy home. The vet will check for parasites, assess development, start the vaccine series, and confirm deworming status. Early exams also establish a health baseline.
What vaccines does a puppy need in the first year?
Core vaccines include distemper, parvovirus, adenovirus (DAP), and rabies. Non-core vaccines — Bordetella, leptospirosis, Lyme disease — are recommended based on lifestyle and regional risk. The full DAP series typically requires 3–4 doses ending at 16 weeks, followed by a booster at 12 months.
Can puppies go outside before they are fully vaccinated?
Puppies can go outside in low-risk settings — your own yard, the homes of vaccinated dogs — before completing vaccines. Avoid dog parks, pet stores, and areas where unknown dogs congregate until 2 weeks after the final puppy series dose. The socialization benefit of early exposure outweighs isolation risk when locations are chosen carefully.