Pet Vaccination 101

Vaccinations are central to your pet’s overall wellness by preventing serious or fatal diseases and helping pets live longer, healthier lives. Each vaccine is considered core or non-core—all pets need the core vaccines, but only pets with certain lifestyle and risk factors need the non-core vaccines. These vaccine options can be confusing, but Mercer Street Veterinary Hospital is making them simple for you—we explain vaccine importance, and help you understand the diseases that vaccines can protect your pet against.

Why are pet vaccinations important?

Vaccines use small pieces or whole, inactive, versions of bacteria and viruses to stimulate your pet’s immune system to make antibodies against those pathogens. When your vaccinated pet becomes infected with the real thing, their immune system “remembers” the pathogen and quickly and effectively will fight the disease and prevent your pet from getting sick. Without vaccination, the immune response is too slow, and pets can become seriously ill or die while the pathogens invade their defenseless cells. Some diseases we vaccinate against, including rabies, are zoonotic—meaning they can spread from animals to humans—so vaccinating all pets not only keeps your own pet safe, but also reduces disease spread to other community pets and people.

Pet vaccination risks

Many people are concerned about vaccine side effects and over-vaccinating risks for their pets. Although vaccines are safe for most pets, adverse reactions, ranging from pain at the injection site to a severe allergic reaction called anaphylaxis, do sometimes occur. Severe allergic reactions are rare, but may result in hives, facial swelling, fever, diarrhea, shock, or death. If your pet does react to a vaccine, your veterinarian will evaluate their risk factors and determine if additional boosters are necessary, or if medications can prevent future reactions. Some autoimmune conditions can flare up after vaccination, so risks and benefits must be carefully weighed for these patients.

Our veterinary team will carefully assess your pet’s individual risk factors, health status, age, and lifestyle to determine which vaccines they need, and will weigh your pet’s disease risks versus vaccination risks to formulate their individualized protocol. A titer test, which measures antibody levels to determine when boosters are needed, rather than automatically giving vaccine boosters to all pets, can help reduce vaccine risks.

Dog vaccines

Dog vaccines are grouped into core and non-core categories. The core vaccines include rabies and the distemper combination, which may be called DAP, DHPP, or DA2PP. These vaccines protect against the following diseases: 

• Rabies — This virus attacks the nervous systems and kills nearly 100% of those infected, including pets, wildlife, and people. Rabies vaccination is required by law to help keep the community safe from this deadly disease. 
• Distemper — Distemper virus mostly affects puppies, causing serious respiratory and nervous system disease. Most unvaccinated pets who contract distemper don’t survive, and survivors are usually left with lasting neurological problems.
• Adenovirus — Also known as infectious hepatitis, adenovirus causes respiratory infections, liver or kidney failure, or eye problems.
• Parvovirus — Parvovirus is extremely contagious and causes severe vomiting, diarrhea, dehydration, fever, lethargy, and sepsis. Parvo often affects whole litters of puppies, and some will likely die, despite treatment.
• Parainfluenza — Parainfluenza may be included with the distemper vaccine or a separate kennel cough vaccine. This virus causes flu-like respiratory symptoms and can lead to pneumonia.

Non-core, or lifestyle-based vaccines for dogs include:

• Bordetella — This bacteria is one of many that cause infectious respiratory disease (i.e., kennel cough, or CIRDC) in dogs. Dogs who frequent day-care, boarding, or grooming facilities require Bordetella vaccination yearly or every six months.
• Leptospirosis — Leptospirosis is spread through infected wildlife or rodent urine, which may contaminate water sources. Dogs who swim, spend time near wildlife, or live in endemic areas may benefit from leptospirosis vaccination. 
• Lyme disease — The Borrelia burgdorferi bacteria that causes Lyme disease is spread through tick bites, so this vaccine is recommended for pets with frequent tick exposure.
• Canine influenza — Canine influenza causes fever, lethargy, cough and, rarely, leads to pneumonia. Vaccination may be required or recommended for pets in boarding or day-care facilities with other dogs.

Cat vaccines

Core vaccines for cats, which include rabies and a combination vaccine similar to distemper for dogs, called FVRCP in cats, protect against:

• Feline viral rhinotracheitis — Most kittens become infected with feline herpesvirus-1, which causes sneezing, congestion, conjunctivitis, and eye ulcers, and then becomes dormant. The virus can reactivate later in life, usually because of stress or concurrent illness, but vaccination can help reduce flare-up incidence and severity.
• Calicivirus — Calicivirus causes respiratory infection and mouth ulcers, and can lead to a chronic oral and gingival inflammation called stomatitis.
• Panleukopenia — Panleukopenia is similar to canine parvovirus, and causes vomiting, diarrhea, fever, and lethargy. This virus hampers immune system function by reducing white blood cells, so infected cats are vulnerable to secondary infections that may be severe or deadly.

Non-core vaccines for cats include:

• Feline leukemia virus (FeLV) —This retrovirus attacks the immune system and can leave infected cats vulnerable to infections, inflammatory conditions, or cancer throughout their reduced lifespan. All kittens should receive an initial FeLV vaccination series, but continued adult vaccinations are recommended only for cats who go outside or live with an infected housemate. 
• Bordetella—The same bacteria that infect dogs can also cause respiratory disease in cats who live in catteries or shelters, but rarely affect house cats.

Vaccination protocols may seem complicated, but your veterinarian can help you assess your pet’s risks to develop a customized protocol. Schedule a visit with Mercer Street Animal Hospital to update your pet’s vaccines, or to learn more about vaccine options, benefits, and risks.