Vaccines are one of the most important tools we have in veterinary medicine to protect our pets from serious, and sometimes fatal, diseases. August is Vaccine Awareness Month, making it the perfect time to talk about how vaccines work, which vaccines your pet may need, how often they should be given, and why preventive care matters even for pets who spend most of their time at home.

Vaccines work by safely introducing the immune system to a disease-causing organism or a piece of that organism. Depending on the vaccine, this may involve a modified-live organism, an inactivated (killed) organism, or a recombinant vaccine that uses specific components of a pathogen to stimulate immunity.

Think of a vaccine as a practice drill for the immune system.

The immune system needs to recognize a threat before it can effectively fight it. A vaccine gives the immune system a safe opportunity to “learn” what a particular disease looks like and how to respond. Vaccines may also contain ingredients called adjuvants, which help stimulate the immune response so the body recognizes the vaccine as something worth paying attention to.

After vaccination, the immune system develops immunologic memory. If your pet later encounters the real disease, that memory allows the immune system to respond more quickly and effectively.

This process has allowed veterinary medicine to dramatically reduce the number of pets suffering from diseases that can otherwise cause severe illness or death.

Not every dog has exactly the same vaccination needs. Our veterinarians will consider your dog’s age, lifestyle, travel, environment, health history, and potential exposure when creating an individualized vaccine plan.

Here are the vaccines we commonly discuss for dogs in our area:

Rabies vaccination is one of the most important vaccines your pet can receive.

Rabies is a deadly viral disease that affects the nervous system. It is most commonly transmitted through the saliva of an infected animal, usually through a bite. Once clinical signs develop, rabies is essentially always fatal.

Even more importantly, rabies is zoonotic, meaning it can spread from animals to people. Because of the serious public-health implications, rabies vaccination is required for dogs and cats in Georgia. Georgia law requires dogs and cats 12 weeks of age and older to have a current, approved rabies vaccination.

According to the American Animal Hospital Association (AAHA), rabies is also considered a core vaccine for dogs and cats.

DHPP is a combination vaccine that protects against several important canine viruses:

One of the diseases we are particularly concerned about is parvovirus (parvo). Parvo is extremely contagious and can cause severe vomiting, diarrhea, dehydration, immune suppression, and potentially fatal complications. It is especially dangerous for puppies and young dogs, and the virus can persist in an environment for years — making it especially contagious.

Distemper and adenovirus can also cause serious, potentially life-threatening disease. These vaccines are considered core vaccines and are recommended for dogs regardless of lifestyle.

Leptospirosis is a bacterial disease that can cause severe illness and failure of multiple organs. It is commonly spread through the urine of infected animals and wildlife, including rodents and other wildlife that may live in or around our neighborhoods.

Leptospirosis is also zoonotic, meaning infected animals can potentially transmit the disease to people.

Importantly, veterinary recommendations have evolved as we have learned more about this disease. AAHA updated its canine vaccination guidelines in 2024 to classify leptospirosis vaccination as a core vaccine for dogs, reflecting the increasing prevalence of disease and the fact that dogs can be exposed in urban, suburban, and rural environments.

Bordetella vaccination helps protect against a common bacterial contributor to kennel cough, a highly contagious upper respiratory illness.

Kennel cough earned its name because one infected dog can potentially spread the illness throughout a kennel or other group setting.

Most cases cause a persistent, irritating cough — often described as a dog repeatedly trying to “hack something up.” Many dogs recover well, especially with appropriate veterinary care. However, respiratory infections can sometimes progress to complications such as bronchitis or pneumonia.

Bordetella is not considered a core vaccine for every dog, but we recommend it for most pets because of how easily respiratory infections can spread. Boarding facilities, daycare centers, groomers, training facilities, dog parks, and other social environments can all increase exposure. Most social facilities will require your pet to have the vaccine.

Canine influenza is the canine equivalent of the flu. It can spread through respiratory droplets and contact with respiratory secretions.

Signs may include:

While many dogs recover, respiratory disease can become more serious in some patients.

CIV vaccination is considered a lifestyle vaccine rather than a core vaccine. We particularly recommend it if your dog frequently socializes with other dogs through daycare, boarding, grooming, dog parks, or other group activities.

Lyme disease is transmitted by ticks. It can often be treated successfully, but infection can sometimes lead to significant complications, particularly when it goes untreated.

Lyme disease is also a concern for people because infected ticks can transmit the disease to humans.

Lyme disease is less prevalent in Georgia than in some other parts of the country, so it is not considered a routine core vaccine for dogs in our area. However, vaccination may be appropriate for dogs who travel — especially to areas where Lyme disease is more common.

And remember: vaccination is only one part of Lyme disease prevention. Consistent veterinarian-recommended tick prevention is extremely important.

Cats have their own set of core and lifestyle-based vaccines.

Just like dogs, cats should be protected against rabies. Rabies vaccination is particularly important because cats can encounter wildlife such as bats, raccoons, and other potentially rabid animals — even when their owners consider them indoor pets.

Georgia law requires rabies vaccination for cats as well as dogs.

FVRCP is a combination vaccine that protects cats against several important infectious diseases, including feline herpesvirus, calicivirus, and panleukopenia.

These diseases can cause serious respiratory and systemic illness, particularly in kittens.

FVRCP is considered a core vaccine for cats.

Feline leukemia virus is a serious infectious disease that can cause immune suppression, anemia, cancer, and other potentially fatal complications.

FeLV vaccination is particularly important for young cats and for cats that spend time outside or around other cats. Current feline vaccination guidelines consider FeLV a core vaccine for kittens and young cats, with recommendations for continued vaccination based on the individual cat’s lifestyle.

Vaccination schedules depend on your pet’s age, previous vaccine history, health, lifestyle, the specific vaccine used, and local requirements. Your veterinarian will determine the appropriate schedule for your individual pet, but here are some general guidelines:

The best vaccination schedule is an individualized one. If you’re unsure whether your pet is due, bring your vaccine records to your veterinary team and we’ll help you determine what is appropriate.

If you have a new puppy or kitten, check out our complete puppy care guide for everything you need to know about starting them off right.

A pet’s lifestyle is an important part of determining which vaccines are appropriate, but “indoor only” does not mean “zero risk.”

For example, rabies vaccination remains important and is required in Georgia.

Even an indoor pet could accidentally escape through an open door, encounter wildlife, or have an unexpected exposure. A bat or other animal could potentially enter the home. You may also suddenly need to board your pet, travel, visit another facility, or evacuate during an emergency.

There is another important consideration: what happens if an unvaccinated pet bites or is exposed to someone or something that could carry rabies?

Georgia’s public-health system has specific procedures for animals involved in potential rabies exposures and for pets that bite other pets or humans. County health authorities are responsible for rabies control and often require strict quarantine or even euthanasia in extreme cases.

The good news is that not every vaccine is necessary for every pet. A truly indoor-only cat may not need the same lifestyle vaccines as a cat that goes outdoors, just as a dog who never encounters other dogs may have different needs than a dog who attends daycare every week.

That’s why we tailor vaccine recommendations to the individual patient.

No medical treatment is completely without risk, but modern veterinary vaccines have a strong safety record, and serious vaccine reactions are uncommon.

Some pets may experience mild, temporary effects after vaccination, such as soreness, tiredness, decreased appetite, or a mild fever.

Rarely, a pet may experience a more significant allergic reaction. Signs can include:

If your pet develops signs of a significant allergic reaction after vaccination, contact your veterinarian or seek emergency veterinary care immediately.

The risk of a serious reaction is low, while the consequences of diseases such as rabies, parvovirus, distemper, and leptospirosis can be devastating. For most pets, the benefits of appropriate vaccination far outweigh the risks.

In recent years we have also found a correlation of tumors in cats with certain kinds of vaccines. There is a rare but serious condition called feline injection-site sarcoma (FISS). These tumors can develop at sites where vaccines or other injections have been administered.

Current feline guidelines recommend appropriate vaccine-site practices, including administering vaccines in locations where a tumor could be more readily identified and treated if one were to develop.

There are also different vaccine technologies available. Some recombinant feline vaccines, including the ones we exclusively use in our patients, do not require an adjuvant and have been associated with a reduced risk of injection-site sarcomas.

Your veterinarian can help determine which vaccine products and vaccination strategy are most appropriate for your cat.

Vaccines don’t just protect your individual pet — they help protect the larger community, too.

When we vaccinate appropriately, we reduce the number of susceptible animals and help limit the spread of infectious diseases. This is especially important for zoonotic diseases such as rabies and leptospirosis, which can affect both animals and people.

The goal isn’t to give every pet every vaccine. The goal is to give each pet the vaccines they need, at the right time, based on their individual risk.

If you aren’t sure whether your pet is up to date, August is a great time to check! Schedule your pet’s wellness exams and let us help create a personalized prevention plan that keeps your pet — and your community — healthy.

And remember, vaccines are only one piece of preventive healthcare. Parasites can pose another serious threat to pets and their families. Check out our blog on parasite prevention and learn more about keeping your pet protected year-round.