Canine vaccination guidelines in Israel

This article was written in order to provide Israeli veterinarians with general guidelines for the vaccination of puppies and adult dogs. It is based on the recent recommendations of expert opinions and the current knowledge on infectious diseases and their prevalence in Israel. Vaccinations are strongly recommended as they have been proven to benefit both the health of the individual dog as well as the canine community by inducing or providing protection and “herd immunity” against life-threatening infectious diseases. There are different types of vaccines including those that induce active immunization such as modified live virus (MLV) vaccines, killed/inactivated and recombinant viral-vectored vaccines, and other immunological products that provide passive immunization (e.g. immunoglobulins). The latter products are not in common use in small animal veterinary medicine. The type of the vaccine should be considered when planning the vaccination protocol. The use of MLV (rather than killed viruses) for the vaccination against viral diseases results in enhanced humoral and cellular immune responses and therefore in a longer duration of immunity (DOI). This insight resulted in a shift from yearly adult-dog vaccinations to three-annual vaccinations (i.e. vaccinations every 3-years). Challenge and serological studies indicated that most canine MLV vaccines have probable DOI of 9 years or longer, when given after 16 weeks of age. These guidelines should be considered as a recommendation and not as a standard of care. They allow some flexibility to the veterinarian according to the signalment and health condition of the dog, the designation of the dog (whether a pet, a working or a kennel dog) and its lifestyle, the dog’s habitat, geographic location and weather conditions, the occurrence or absence of disease outbreaks in the vicinity of its living area, and the economic condition of the owners. Accordingly, vaccinations are divided to core and non-core. Core vaccines are targeted against several severe life-threatening viral diseases and are recommended for all dogs regardless of their geographic location or other considerations. These include canine distemper virus (CDV), canine adenovirus type 2 (CAV-2) and canine parvovirus type 2 (CPV-2 variants). As Israel is endemic for rabies, rabies vaccine is also considered a core vaccine in our region. Non-core vaccines are those that should be given only when necessary, to dogs that are exposed or at risk of developing specific infectious diseases at certain periods and under certain circumstances according to their geographic location, habitat and life-style. These include vaccines against leptospirosis, canine infectious respiratory disease (Kennel cough) and canine influenza virus, among others. The list of permitted vaccines for 2020 in Israel can be found in the Israeli Veterinary Services website: https://www.moag.gov.il/vet/Yechidot/TachshirimTrufot/Pirsumim/2020/Pages/ tachshirim_chimim_2020.aspx. This list is updated by the Israeli Veterinary Services annually, and is also included in these guidelines (Table 1). Only approved vaccines should be used in Israel, other vaccines are legally not allowed for importation and use. Only healthy dogs should be vaccinated, following a complete physical examination. Some vaccines are safe for pregnant bitches but others not, it is therefore advised to carefully read the manufacturer’s “summary of product characteristics” sheet before their use. The guidelines below include information on each of the core vaccines, and some of the non-core vaccines, the diseases they can prevent and their usage recommendations. Vaccination failure may occur due to several reasons including the presence of maternal derived antibodies, an inadequately immunogenic vaccine, individual poor response to the vaccine-antigen, or poor handling and/ or keeping conditions of the vaccine. Maternal derived antibodies may neutralize the vaccine and interfere with proper and sufficient immunization, therefore it is recommended to vaccinate pups with a series of 2-4 (preferably 3-4) consecutive core vaccines until the age of 16 weeks (e.g. every 2-4 weeks starting at the age of 6-8 weeks). The final vaccination as a pup should be given at the age of 16 weeks or later (Table 2), when the maternally-derived antibody concentration is expected to decrease to low levels that are presumed not to interfere, and allow adequate immunization. When only one core vaccination can be afforded by the pet owners, the World Small Animal Veterinary Association Vaccination Guidelines Group (WSAVA-VGG) recommends vaccination at the age of 16 weeks or later. Thereafter, a booster vaccine should initially be given between the age of 6-12 months, and then not more frequently than every 3 years. This is because the DOI for most core vaccines is longer than 3 years and may even remain for the entire lifetime of the dog. Vaccination associated adverse effects may occur following vaccinations and therefore vaccination protocols should be wisely considered and administered. Adverse effects may range from anaphylaxis to autoimmunity as a result of hypersensitivity reactions to the vaccine components. Therefore, the dog should be inspected for at least 30 minutes following vaccination and its owners should be instructed to report the veterinarian of any changes in behavior or clinical signs in the days following vaccination.