What are Vaccinations?
Vaccinations are a very important tool in keeping your pet happy and healthy, by providing significant protection against a number of contagious infectious diseases. Vaccinations work by presenting the immune system with antigens, tiny pieces of a bacterium or virus (pathogen). While the antigens cannot by themselves cause infection, they stimulate the immune system. This stimulation helps the immune system to remember the antigen(s) for later use if needed. If the immune system is later exposed to the actual virus or bacterium, it recognizes the antigen(s) and mounts a full response to the entire pathogen. The goal of vaccination is to prevent illness altogether, or reduce the duration and severity of symptoms should the animal be exposed.
What Vaccinations are Commonly Available?
Vaccinations are generally divided into two categories: core and non-core. Core vaccinations are generally recommended for all animals of a given species to protect them against diseases considered to be especially serious or potentially fatal. These diseases are known to be present throughout North America and present significant concerns for transmission. Non-core vaccines are reserved for cats and dogs that are specifically at higher risk for certain infectious diseases based on age, location and lifestyle.
The American Animal Hospital Association (AAHA) has published guidelines for which canine vaccines are considered core versus non-core, while the American Association of Feline Practitioners (AAFP) has published similar guidelines for pet cats. These categories break down as follows:
• Canine Core: Rabies (required by law); Distemper; Hepatitis; Parvovirus
• Canine Non-Core: Leptospirosis; Lyme; Bordetella (commonly referred to as “Kennel Cough”; Canine Influenza Virus (CIV)
• Feline Core: Rabies (required by law in most states); Panleukopenia; Herpesvirus; Calicivirus;
• Feline Non-Core/Core: Feline Leukemia Virus (FeLV)
o Traditionally considered non-core but recommendations are gradually changing, particularly for kittens
As noted above, vaccination recommendations are made in large part based on an animal’s lifestyle. Age, breed, and medical history are also taken into account. A dog who attends training classes with other dogs regularly, boards while its owners are away, goes to the groomer, or is otherwise regularly exposed to other dogs is considered at higher risk for Bordetella and CIV; vaccinating against these diseases is thus generally recommended for those dogs. At Deepwood, we consider Leptospirosis to be a core vaccine, because it is a contagious disease that can not only cause severe (potentially fatal) liver and kidney disease, but can be transmitted from an infected dog to their owner(s). In the Mid-Atlantic, Lyme Disease is widespread, and for many dogs vaccinating against Lyme is also recommended.
It has long been recommended that outdoor or indoor-outdoor cats receive yearly FeLV vaccinations, but newer guidelines suggest that owners may wish to consider vaccinating indoor cats as well, at least as kittens, so that if they find themselves outdoors they have a higher level of protection.
What About the Risks?
Vaccinating your pet is a medical procedure, and as such, does carry some inherent risk. Every pet is different, and not all pets should have the same vaccine protocols. Vaccine reactions and side effects are uncommon, but they do occur, and you should always monitor your pet after vaccinations for any signs of trouble. The vast majority of vaccine reactions are mild and self-limiting, such as: mild discomfort and/or swelling at the injection site, low-grade fever, and/or slight reduction in appetite. Such reactions, if they do occur, typically last no more than a few hours, but if they are prolonged, a recheck with your vet may be warranted. More serious reactions are considered allergic or hypersensitivity reactions, such as vomiting, diarrhea, swelling of the face or feet, or difficulty breathing (the last of these is extremely rare). Allergic reactions should be addressed by a veterinary professional as soon as possible. They generally respond well to outpatient supportive care, although in rare instances more aggressive treatment is needed. If your dog or cat displays any unusual symptoms after receiving vaccinations, please call us right away!
Research indicates that the more vaccines a pet receives at a single visit, the higher their chance of a vaccine reaction. This pertains primarily to small and medium-sized dogs. While a 60-lb Labrador Retriever can generally handle four vaccinations at one time, the same can often not be said of a 5 lb Yorkshire Terrier. Vaccination protocols for smaller dogs generally involve spreading the vaccine visits out with no more than 2-3 vaccines at once, to minimize the chance of reactions. If your pet has previously experienced a vaccine reaction, you can take the following steps down the road to decrease the chance of it happening again:
• Spread out vaccines. If your pet had a reaction after receiving more than one vaccine at once, next time consider having your vet give vaccines individually. This decreases the stimulus for the immune system.
• Pre-medicate with diphenhydramine (Benadryl). Talk to your veterinarian or vet tech about whether your pet should receive an antihistamine dose at home prior to their appointment, or whether an injection should be given at the visit (before vaccinations). Do not give any medication without first speaking to a veterinary professional.
• Skip it. Some pets have immune systems that react badly to specific vaccines. The decision to eliminate any vaccine from your pet’s protocol should be made only after a thorough discussion with your veterinarian of your pet’s particular lifestyle, as well as of the pros and cons of giving versus not giving the vaccine.
In extremely rare instances, vaccinations can trigger immune-mediated conditions that affect the body, leading to severe and potentially fatal illness. The risk of these conditions occurring after vaccination is very low, and does not outweigh the benefit of protection provided. However, if your pet already has a documented immune-mediated condition, a modified vaccination protocol will likely be recommended. This also applies to animals receiving chemotherapy affecting their immune system, as well as animals with other conditions that may alter their body’s ability to process vaccinations.
Vaccine-Associated Sarcomas/Fibrosarcomas are a rare tumor of connective tissue that have been documented to occur at the site of vaccination in some cats. While this response to vaccination is exceedingly uncommon, it generally necessitates a prompt, aggressive surgical response, and the tumor may recur if not completely removed. Again, as the risk is extremely,. low, it is considered to be outweighed by the tremendous benefits of protection against infectious diseases. However, if you are a cat owner and have questions or concerns about Vaccine-Associated Sarcomas, please do not hesitate to discuss the issue with your veterinarian.