COVID-19 Update: AAHA staff is currently working remotely and will support our members virtually. All orders are currently shipping as normal.
Click here for more information.

Managing dogs overdue for vaccines

Overdue for core vaccines

1. How many doses of vaccine should be given to a dog presented for their initial vaccine series if the patient is older than 16 weeks of age?

Two sequential doses, administered 2 to 4 wk apart, are conventionally recommended. Doing so is essential when initially administering a killed (inactivated) vaccine. Rabies is the exception to this rule (see the FAQs on RABIES).

Among dogs 16 wk of age and older, administration of a single dose of a core vaccine (DAP: distemper virus, adenovirus-2, parvovirus, +/- parainfluenza virus) is likely to immunize. However, given that a small number of dogs at 16 wks of age may still have interfering levels of maternally derived antibody, administering 2 doses, 2 to 4 wk apart, is a reasonable recommendation.

Overdue for noncore vaccines

2. When administering the initial doses of a killed (inactivated) vaccine that requires 2 doses to immunize (e.g., leptospirosis, Lyme disease, CIV), and the dog does not return for the second dose within 6 weeks after the first dose, does the 2-dose “series” need to be restarted?

Killed (inactivated) vaccines require 2 doses on initial vaccination. The first dose primes the immune system, and the second dose immunizes. While it is ideal to have the second vaccination given within 4 wk, the Task Force considers 6 wk to be the “outside limit” between initial vaccinations, beyond which the series would need to begin again (two additional doses, administered 2 to 4 wk apart).

Rabies vaccine is the exception. In states, jurisdictions, and provinces (Ontario) that require rabies vaccination of dogs, administration of a single dose of rabies vaccine, regardless of the time that has elapsed since the previous dose was administered, is considered to be an immunizing dose. Following revaccination, a dog is considered to be immediately “currently vaccinated” against rabies. See the FAQs within the section on RABIES.

These guidelines are supported by a generous educational grant from
Boehringer Ingelheim USA Inc., Merck Animal Health, and Zoetis.