10-12 week puppy shots: the second core visit

The 10-to-12 week visit is the busiest visit of the puppy series. The second DHPP dose anchors the appointment, but it is also where most US practices first introduce the lifestyle vaccines (Bordetella, Leptospirosis, Lyme), where the first rabies dose becomes possible in many states, and where the conversation about heartworm prevention and parasite control firms up. The UK second jab is typically given at 10 to 12 weeks as well, completing the two-jab primary course.

What is given at this visit

The second DHPP dose is the centrepiece. AAHA 2022 Table 1 calls for DHPP doses at 6-8, 10-12, 14-16 weeks, and a final at or after 16 weeks of age. The 10-12 week dose is the second of four. By this point in the series the puppy's maternally-derived antibody titre has dropped enough that a sizeable proportion of puppies will mount their own response to this dose, even if the 6-week or 8-week dose was blocked. The WSAVA 2024 Guidelines describe approximately 60 percent seroconversion to parvovirus after a 12-week dose, rising sharply with each subsequent dose.

Lifestyle vaccines are typically introduced at this visit because the puppy is now old enough that the product labels permit it and the immune system is mature enough that the reactogenicity profile is lower than at 6-8 weeks. The vet will work through the lifestyle vaccine menu:

• Bordetella bronchiseptica (kennel cough). The intranasal form can be given as early as 3 weeks per label, but most practices wait for the 12-week visit if no boarding has been booked. Injectable Bordetella product labels typically start at 6-8 weeks. Required by most boarding facilities, daycares, training classes, and dog shows.
• Leptospirosis. The first of two doses. AAHA 2022 classes Lepto as non-core but "strongly recommended for dogs at risk of exposure." In practice that covers most of the US. Lepto is given as a 2-dose primary series 3-4 weeks apart, so the first dose at 12 weeks pairs with a second at 14-16 weeks.
• Lyme (Borrelia burgdorferi). The first of two doses for puppies in tick-endemic regions (Northeast US, upper Midwest). See our Lyme vaccine guide for the region map.
• Rabies. The NASPHV Compendium of Animal Rabies Prevention and Control sets the federal-reference minimum at 12 weeks, and most states have adopted that minimum (California, New York, Texas, Florida, Illinois, Pennsylvania, Massachusetts). Some states (Michigan, Virginia) require 16 weeks. See our state-by-state rabies law pages.
• Canine influenza. Bivalent CIV-H3N2/H3N8 vaccines can be started from 8 weeks. Practices in metro areas with reported outbreaks may begin the series here.

Most vets will not stack all of these in a single visit even when indicated. AAHA 2022's reactogenicity guidance discourages giving more than two or three injectable vaccines in one appointment for small-breed puppies because the cumulative antigen load increases the rate of post-vaccination reactions. The common solution is to give the core DHPP and rabies in one visit, with Lepto and Lyme split into the next visit (or vice versa). For the reaction-rate context, see our small-breed puppy vaccination page.

How the second DHPP works

The first dose primed the puppy's naive B cells against canine parvovirus, distemper, adenovirus, and parainfluenza antigens. Some of those B cells differentiated into long-lived memory cells in the bone marrow and spleen. The second dose, given 3-4 weeks later, recruits those memory cells back into the active immune response, producing a much steeper and faster antibody curve than the first dose did. This is the immunological basis of every prime-boost vaccine strategy in human and veterinary medicine. The reason the puppy series uses four doses instead of two is not that the immune system needs four boosts, but that maternal-antibody interference still blocks the first one, two, or three doses in some puppies and the fourth dose is the safety net for the late-decay puppies.

The implication is that if the first dose was blocked by maternal antibody (the puppy did not seroconvert), the "second" dose is actually behaving as a primary dose and needs its own boost 3-4 weeks later. That puppy needs the 14-16 week dose and the post-16-week dose to complete a real two-dose primary series. This is why WSAVA emphasises the post-16-week dose as the "most important dose in the series": it is the one that catches every late-decay puppy.

State variation in when rabies starts

Rabies vaccination is the only canine vaccine mandated by law in the United States and the law sits at state (sometimes county) level. The NASPHV Compendium of Animal Rabies Prevention and Control is the federal reference document most state laws follow. The Compendium sets a minimum age of 3 months (12 weeks). Most states adopt this minimum directly. The notable exceptions where the state code sets a later minimum:

• Michigan: 4 months (16 weeks) per state code.
• Virginia: 4 months per Virginia Code 3.2-6521.
• Pennsylvania, New Jersey, Connecticut: 12 weeks but with local variation by county.

Even in 12-week-minimum states, vets often hold rabies to the 14-16 week visit to avoid stacking too many injectable vaccines at the 10-12 week appointment. For state-specific rules see our state pages (California, Texas, New York, Florida, Hawaii rabies-free).

Cost of the 10-12 week visit

The cost varies widely depending on which lifestyle vaccines are added.

UK pricing for the second jab is more uniform: £35-£55 at an independent vet for DHPPi+L (often included in a two-jab package of £80-£150 per the ManyPets 2025 UK vet-cost survey). UK rabies is not in the standard course and is only given for international travel under the Pet Travel scheme. See our UK cost guide for details.

Common questions about 10-12 week vaccinations