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October 2022
2022 AAHA Canine Vaccination Guidelines
These guidelines update and extend the 2017 AAHA Canine Vaccination Guidelines, providing a current and comprehensive resource for making informed decisions when designing vaccination protocols for dogs. Such protocols promote team commitment, consistent implementation, and effective client education.
A good rule of thumb is, “When in doubt, vaccinate.”
Executive Summary
These guidelines were prepared by a task force of experts convened by the American Animal Hospital Association. This document is intended as a guideline only, not an AAHA standard of care. These guidelines and recommendations should not be construed as dictating an exclusive protocol, course of treatment, or procedure. Variations in practice may be warranted based on the needs of the individual patient, resources, and limitations unique to each individual practice setting. Evidence-based support for specific recommendations has been cited whenever possible and appropriate. Other recommendations are based on practical clinical experience and a consensus of expert opinion. Further research is needed to document some of these recommendations. Because each case is different, veterinarians must base their decisions on the best available scientific evidence in conjunction with their own knowledge and experience.
This Executive Summary is not a replacement for reading the guidelines in their entirety. The full guidelines are published in the (J Am Anim Hosp Assoc 2022;58:213–230. DOI 10.5326/JAAHA-MS-Canine Vaccination Guidelines)
Vaccination is a cornerstone of canine preventive healthcare and one of the most cost-effective ways of maintaining a dog’s health, longevity, and quality of life. It serves a public health function by forming a barrier against several zoonotic diseases affecting dogs and humans. And vaccination is an important means of nurturing a long-term veterinarian-client-patient relationship.
Universal, routine vaccination for high-morbidity or high-mortality diseases such as canine distemper, canine parvovirus enteritis, and rabies is necessary for individual health and to maintain herd immunity, thereby reducing the risk for disease spread and outbreaks. As has been clearly demonstrated, reductions in population-level vaccination rates without eradication of the pathogen inevitably result in outbreaks.
The 2022 AAHA Canine Vaccination Guidelines provide updated vaccination recommendations and dosing schedules for canine vaccines licensed in the United States. The guidelines have been revised from prior versions to provide consolidated and updated clinical information, allowing the veterinarian to select the best vaccines and protocols to fit individual patient needs.
Overview
Before presenting specific recommendations, the guidelines provide an overview of canine vaccines, defining and discussing important topics such as vaccine efficacy and effectiveness, causes of vaccine failure, and duration of immunity.
To complete the overview, Table 1 describes key characteristics of the four general categories of canine vaccines based on the physical attributes of the immunizing antigen: attenuated, inactivated, recombinant, and toxoid. (For Table 1, see the guidelines in the Journal of the American Animal Hospital Association referenced above, or online at aaha.org/guidelines.)
Shelters that vaccinate all animals on entry provide optimum herd immunity within their population.
Recommendations for Core and Noncore Vaccines
Based on existing data and Task Force expertise, the Task Force separated vaccines into two categories: core and noncore. Core vaccines are defined by the Task Force as recommended for all dogs irrespective of lifestyle, unless there is a specific medical reason not to vaccinate. Examples of core vaccines include canine distemper virus, canine adenovirus type 2, canine parvovirus type 2, and rabies. Noncore vaccines, which are just as essential as core, are recommended for some dogs based on lifestyle, geographic location, and risk of exposure. Canine leptospirosis vaccine, canine Bordetella vaccine, canine Lyme vaccine, canine influenza vaccine, and the Western diamondback rattlesnake toxoid are considered noncore.
The designation of a core vaccine was unanimously supported by all members of the Task Force, but there was not always consensus regarding noncore vaccines. For example, some members of the Task Force asserted that the canine leptospirosis vaccine should be considered a core vaccine based on the increasing geographical prevalence of the disease. However, others preferred to leave this decision up to the veterinarian. For regions where noncore pathogens are endemic, like canine leptospirosis and canine Lyme disease, these vaccines may be considered core vaccines. As travel with pets becomes more popular and vector-borne diseases spread, patients should be carefully assessed at least annually to determine their vaccine requirements.
Table 2 lists core and noncore vaccines as determined by the Task Force and their dosing recommendations. (For Table 2, see the guidelines in the Journal of the American Animal Hospital Association referenced above, or online at aaha.org/guidelines.)
These recommendations should be considered general rather than universally prescriptive. Veterinarians have the discretion to administer vaccines off-label when scientific data, local circumstances, or evolving standards of care support that decision. In those situations, informed consent from the client is still an important consideration.
The guidelines are to be considered discretionary recommendations. The Task Force emphasizes that practitioners should be aware of the importance of reviewing and following the manufacturer’s label instructions for specific vaccines, including instructions on proper mixing and use of diluents. Different types of vaccines for the same pathogen may induce different immunologic responses depending on vaccine technology, formulation, route of administration, and patient factors.
Vaccination Considerations
To augment the recommendations, a lengthy section of the guidelines discusses key vaccination considerations relevant to various antigens. The discussion is divided into six sections devoted to canine distemper virus (CDV), canine parvovirus (CPV), and canine adenovirus; rabies; leptospirosis; Borrelia (Lyme disease); Bordetella, canine parainfluenza, and canine influenza; and rattlesnake toxoid. The first five sections discuss the disease(s) caused by the pathogen(s), provide information about the relevant vaccine(s) and why they are categorized as a core or noncore, and state the guidelines’ recommendations for vaccination and revaccination. Detection of antibodies after vaccination and relevant information unique to each vaccine are also addressed. The sixth section, on rattlesnake toxoid, evaluates existing research into its efficacy.
Following are some excerpts from the discussion of key vaccine considerations. These excerpts are a small sample of what the guidelines have to offer. Reading the excerpts is no substitute for reading the guidelines in their entirety.
Most dogs in North America should be
considered at risk for leptospirosis.
In the case of canine parvovirus, although host-related factors may play a role, failure to complete primary vaccine schedules or errors in vaccine storage or administration may account for many or most “vaccine failures.”
For rabies, the guidelines note that legal requirements and exemptions may vary by jurisdiction. Veterinarians serving clients in multiple jurisdictions with varying requirements should generally apply the requirements of the jurisdiction where the animal resides.
The Task Force warns that most dogs in North America should be considered at risk for leptospirosis and that vaccination may be necessary to meet requirements for importation and transport of dogs. In addition, the Task Force recommends the use of the 4-serovar vaccines for protection against the most relevant pathogens because vaccines induce only partial or no immunity to heterologous serogroups.
There are four types of approved Borrelia vaccines, and the guidelines briefly explain the unusual way in which they exert their protective effect. Vaccination should be complemented with an ectoparasite control program as prevention of tick feeding prevents disease transmission. Predisposition to Lyme nephritis has been suggested for retriever breeds, and this may warrant additional consideration for vaccination for these breeds.
For Bordetella, canine parainfluenza, and canine influenza, there may be an immunological benefit in combining different vaccines and routes of administration in a primary series. The guidelines briefly describe and discuss this strategy, called “heterologous prime-boost.”
Finally, for rattlesnake toxoid, the guidelines call attention to the lack of peer-reviewed published data, adding that polyvalent antivenin therapy is an alternative to vaccination when a rattlesnake bite is suspected.
Shelter Dogs and Puppies
Animal shelters represent one of the most challenging environments for the prevention and control of canine infectious disease. The guidelines provide a detailed discussion of current recommendations for vaccination of shelter dogs—at presentation, as resident animals, or in case of a disease outbreak. Other high-density or high-risk environments, including foster homes, foster-based rescues, breeding facilities, sanctuaries, boarding kennels, and pet stores, should consider following the same vaccination protocol.
Shelters that vaccinate all animals on entry provide optimum herd immunity within their population. Conversely, shelters that do not vaccinate on entry or do not vaccinate all dogs are at higher risk for an infectious disease outbreak.
Serological testing can help to manage disease outbreaks, particularly in the case of CDV and CPV, as opposed to depopulation or prolonged lockdown of the shelter.
Serologic Titers
Recognizing the limitations of existing research, no values for “protective titers” are indicated in these guidelines, although some commercial laboratories provide them. Altogether, routine titer testing to ascertain the necessity to revaccinate at currently recommended intervals is not usually advised, except in cases in which dogs have a history of adverse responses to vaccination, or there is a suspicion of vaccine-related autoimmune disease, or when owners hesitate or resist—in which case client communication and education may be warranted.
Postvaccination Adverse Events and Reactions
Undesired or unexpected consequences after vaccination include failure to provide protection from disease and adverse reactions associated with vaccine administration. Failure to provide protective immunity is primarily of concern in very young or very old dogs. Adverse reactions may be due to a number of causes, ranging from inappropriate administration of a modified-live product to genetic predisposition. Localized cell-mediated immune reactions or generalized systemic responses can occur after vaccination. Type I hypersensitivity reactions have been linked to vaccination, but vaccine associations with other immune-mediated diseases are less consistent. This may indicate that factors besides vaccine antigens are responsible for immune disease sequelae following vaccination.
Other topics addressed in this section include reducing the number of vaccines administered at a single office visit, whether to treat at-risk patients with diphenhydramine before vaccination, the importance of informed consent, and reporting adverse events.
The guidelines warn that reducing the administered volume of any vaccine below the manufacturer’s recommended volume (“split dosing”) is not advised. Doing so may result in legal liability.
Storage and Handling, Labels, and Licensure
Vaccine effectiveness relies on proper storage and handling. The guidelines provide recommendations for keeping vaccines in a temperature-controlled environment from the time they leave the manufacturer to the time of their administration. The guidelines also recommend use of new, sterile syringes and needles for administering vaccines and warn that delays in vaccine reconstitution and administration can decrease vaccine efficacy.
Vaccine labels have recently undergone considerable changes; veterinarians are encouraged to review individual manufacturer efficacy and safety data online. Licensure standards for fully licensed products are similar in the United States and Canada.
Client Education, Team Training
A well-defined vaccination protocol with consistent messaging provides a framework for the veterinary team. At minimum, a vaccination schedule should consist of anatomical location of vaccine administration, route of administration, age requirements and/or restrictions, and frequency of administration. A vaccination protocol should be created with the patient’s needs and lifestyle in mind, with buy-in from the client. Wellness plans often include recommended vaccines and help the healthcare team deliver a consistent message. Each practice should consider creating a source of client education materials, discharge instructions for practice teams, and brief statements about each vaccine and the disease(s) it prevents.
To counter hesitancy and skepticism, client education can play a key role by helping pet owners understand that vaccination is a safe, effective, and necessary part of their pet’s healthcare plan and that it acts as a barrier to zoonotic diseases. All members of the veterinary team should be able to communicate a consistent message about the importance of immunization. Protocols for baseline and individualized vaccination plans are useful tools not only for implementing vaccination practices but also for client education.
Licensed canine vaccines have a high degree of proven safety and efficacy. A good rule of thumb is, “When in doubt, vaccinate.”
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2022 AAHA Canine Vaccination Guidelines At a Glance |
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These guidelines update and extend the 2017 AAHA Canine Vaccination Guidelines, providing a current and comprehensive resource for making informed decisions when designing vaccination protocols for dogs. Such protocols promote team commitment, consistent implementation, and effective client education. Vaccination best practices are based on the individual patient’s history and risk of disease exposure, as well as general herd health considerations. These guidelines empower veterinarians to make the best possible personalized recommendations for their patients by determining which vaccines are essential for each individual dog, by:
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Constance Hardesty is an award-winning freelance writer living in Colorado. She is the former editor in chief of AAHA. |
Photo credits: Eva Blanco/iStock via Getty Images; PeopleImages/iStock via Getty Images