Routine vaccinations are one of the cornerstones of keeping our pets healthy. Many of the diseases that we vaccinate against can cause severe illness in pets (and people), can be costly to treat, and can even result in death.

Different vaccines have different durations of action, so some vaccines need to be boosted three to four weeks after the initial vaccine. Some vaccines are administered yearly, while some are effective for up to 3 years. Typically, vaccines are separated into two categories: core (recommended for all pets) and non-core (based on lifestyle).

Core vaccines

No specific treatment for these diseases exist, and animals are supported with fluids and medications in hopes that their immune system eventually clears the disease. Many dogs and cats every year succumb to these viral diseases that can be prevented with vaccination.

For dogs

  • Rabies: This is a deadly disease with no cure that can be passed to people. Rabies is spread via bites.
  • Distemper/Adenovirus/Parvovirus (DAP):
    • Distemper is spread via the respiratory system, but infected dogs can shed the virus in most all bodily secretions. This virus can cause problems with the nervous and gastrointestinal system, as well as changes to the eyes, heart, and skin.
    • Adenovirus causes liver disease, but can also affect the respiratory tract, nervous system, eyes, and bloodstream. It is spread via contact with contaminated urine, saliva, or feces.
    • Parvovirus is spread via contact with feces and causes severe vomiting and diarrhea. The virus can survive for a long time in the environment.

For cats

  • Rabies: This is a deadly disease with no cure that can be passed to people. Rabies is spread via bites.
  • Feline Viral Rhinotracheitis/Calicivirus/Panleukopenia (FVRCP):
    • Feline viral rhinotracheitis is spread by contact with the respiratory system and causes clinical signs in the nose and eyes.
    • Calicivirus is usually spread via contact with infected saliva or secretions from the eyes or nose, although it has also been found in blood, urine, and feces. It can cause upper respiratory disease and/or lameness. A highly fatal form of calicivirus was first documented in 2020 and can cause bleeding disorders.
    • Panleukopenia is similar to parvovirus in dogs and is spread via contact with feces. It can survive in the environment for long periods of time and can cause vomiting, diarrhea, and neurologic disease.

Non-core vaccines

For dogs

  • Bordetella: This vaccination stimulates an immune response against the Bordetella bacteria and/or other viruses that cause upper respiratory infections, which typically manifest as coughing, sneezing, lethargy, and discharge from the eyes and/or nose. These diseases are spread by inhalation, so this vaccine is typically recommended for dogs that spend time around other dogs of unknown vaccine status, such as dogs that go to boarding or grooming facilities, doggie day care, dog shows, or dog parks.
  • Leptospirosis: This is a bacterial infection that can cause liver and kidney failure and can be spread to people. Dogs typically contract leptospirosis after contact with water that has been contaminated with urine of wildlife infected with leptospirosis. This vaccine is recommended for dogs that spend a lot of time outdoors hiking, camping, or swimming; although reports of leptospirosis-infected dogs living in cities has been documented via contact with puddles of water containing rat urine. Any dog owner with a dog that spends time outside should discuss this vaccination with their veterinarian.
  • Lyme: This bacterial disease is passed via tick bite and can cause lameness, kidney disease, lethargy, fever, and decreased appetite. The ticks that carry Lyme disease are most commonly found in the northeast US, so this vaccine is recommended for dogs that live or travel to this region. Tick prevention is also very important in the prevention of Lyme disease.
  • Influenza: This viral disease is passed via respiratory secretions and can cause symptoms that can range from mild cough to severe fever and pneumonia. This vaccine is recommended for dogs that travel to dog shows or spend time around other dogs of unknown health and vaccine status.

For cats

  • Feline leukemia: This viral disease is spread by mutual grooming and/or sharing food/water bowls or litterboxes. It can lead to suppression of the immune system, cancer, blood disorders, and problems with the nervous system. This vaccine is recommended for cats that spend time outside unsupervised, interact nose-to-nose through a screen door with stray cats, or share bowls or litterboxes with stray cats. Because kittens are more likely to become severely ill from feline leukemia, it is recommended that all kittens under one year of age receive two doses of the feline leukemia vaccine, regardless of their lifestyle.

Vaccine reactions in dogs and cats

Virtually any medical procedure or intervention can also have associated risks. Sometimes, animals will be slightly sore, tired, or may vomit or have diarrhea after being vaccinated. Some pets may be hypersensitive to vaccination and can exhibit facial swelling, hives, or (in rare instances) go into shock. Administering certain medications before vaccination can help sensitive animals tolerate vaccines better.

In very rare instances, vaccines have been linked to the development of certain types of cancerous tumors in cats, although vaccine additives have been modified in order to decrease the likelihood of this happening. Because vaccines stimulate the immune system, they also have the potential to induce certain types of autoimmune diseases in dogs, although this is also very rare.

In the vast majority of animals, the benefits of vaccination greatly outweigh the risks. Always talk with your veterinarian who can help you make the best choice for your pet.