Dog Vaccinations: What you need to know

mini schnauzer vaccination

By Erica Tramuta-Drobnis, VMD, MPH, CPH

Why do we vaccinate dogs? 

Dogs, like people, are exposed to a variety of contagious diseases. Many have successful vaccines available to help protect your dog from illness and death. Some dog vaccines are considered core, while others are non-core. With one, the rabies vaccination, being a legal requirement throughout most of the United States. 

Vaccines in dogs have been manufactured and used for years. Many scientific studies demonstrate disease protecting ability, overall safety, and benefits. Vaccine technology and effectiveness have greatly improved over the years. For most, the vaccine benefits far outnumber the risk of reaction and provide critical protection from serious diseases. 

Equally as important, many of the diseases we vaccinate against are highly spreadable to other dogs. By protecting your dog, you safeguard other pets and wildlife against disease. Just because your dog doesn’t interact with other dogs face to face doesn’t mean the pet isn’t exposed to other dogs or other species by way of sniffing or licking the ground in an area where another pet was shedding an infectious disease. 

There was a time in veterinary medicine when vaccines got pet owners into the practice and why pet owners felt their pets needed to see a veterinarian. 

However, veterinary medicine and pet owners have evolved over time. Pet parents recognize that their pets benefit from annual veterinary visits regardless of if they are due for vaccines or not. Scientific studies have shown that not all vaccines are needed annually, and veterinarians recognize this. Still, just as human physicians recommend annual physicals for their patients, vets recommend it for dogs too!



Core vs. non-core dog vaccines 

Core dog vaccines:

  • Parvovirus
  • Distemper
  • Hepatitis
  • Rabies

Non-core dog vaccines:

  • Bordetella (KCV)
  • Parainfluenza
  • Lyme Disease
  • Leptosporosis
  • K9 Flu (Influenza)

Legally, the only vaccine required is the Rabies vaccine. 

However, core vaccines are recommended based on the disease severity, how contagious they are to other dogs, and how commonly they are seen without vaccination. Core vaccines are established by veterinary groups who evaluate the evidence and disease risks.

Non-core vaccines are those additional vaccines recommended based on an individual dog’s exposure risks, including activities engaged in and susceptibility.


What diseases do we vaccinate against in dogs

The following diseases encompass the core vaccines recommended for dogs: Parvovirus, Canine distemper virus, Infectious canine hepatitis, Fatal viral disease rabies, Bordetella (KCV), Parainfluenza (PI). Some are more contagious than others. Core vaccines are globally recommended for all dogs.

At the same time, non-core recommendations should be decided upon by the owner and veterinarian together. Non-core vaccines help prevent the following diseases:  Lyme disease, Leptospirosis (letpto), K9 Flu (influenza).

Many core vaccines are grouped together into one combo vaccine, which minimizes the number of injections and the risk of a vaccine reaction.





The individual diseases could be vaccinated for individually but often combined to minimize the number of injections your pet requires, provide convenience and ultimately, save costs. Additionally, with fewer separate injections, the risk of a vaccine reaction lowers. 

Among different variations, you may see the combo vaccines termed DHPP, DHLPP, 5-in-1, 6-in-1, among others. The terminology comes from the brand of vaccine and the types of diseases included in the immunization combos. DHPP consists of the following: D = Distemper, H = Hepatitis P= Parvovirus and P = Parainfluenza

The L in DHLPP refers to Lepto. While not an actual core vaccine, in some areas of the country, many vets treat it as such. See below for more details.



Parvovirus (Aka “parvo”)

Parvovirus occurs very commonly in the dog population without vaccination. This virus attacks the GI tract, causing severe bloody diarrhea and vomiting, loss of appetite, decreased white blood cells, and a cascade of problems that follow. It can be deadly without treatment, and even with treatment and supportive care, it can still be fatal. In addition to high costs to treat animals with this disease, animals suffer unnecessarily. The vaccines are very safe and effective. Usually, the breeder starts this vaccine at 6 weeks, and then the vaccine responsibilities fall to the new pet owner. 

Parvo vaccination schedule

The parvo vaccination can be given by itself or combined with other vaccines. You may see it as part of the DHPP, DHLPP, 5-in-1, 6-in-1 and others.

Parvo should be given starting at 6 weeks of age every 3-4 weeks through a minimum of 16 weeks. Parvo is then boostered at 1 year then every 3 years. 

When a puppy is born, they have a natural immunity to some diseases via protection from antibodies it receives from the mother. However, these only last up to about 3 months of age. So, we want to time that last dose to ensure protection occurs well after the mom’s antibodies have waned. This is true for all vaccines within the combos. 

Parvo infection provides lifetime immunity. However, because it is usually administered as a combination vaccine, the dog will still likely receive a vaccination for it even if your pet survives an infection. 




Canine distemper virus is a complicated disease that can infect many species, including dogs and their relatives, ferrets and their relatives, raccoons, bears, and the large cat species. It is similar to the virus that causes measles. Signs can include fever and a variety of signs related to the GI and respiratory tract, skin, and the brain issues (neurologic signs). 

It can be hard to diagnose because it looks like other diseases, but routine vaccination can also easily prevent it.

Distemper vaccination schedule

Distemper vaccine is usually included in the combination vaccines (DHPP) and administered on the same vaccine schedule as parvovirus vaccination. For example, the vaccine starts at 6 weeks of age, then every 3-4 weeks through a minimum of 16 weeks. It is boostered at 1 year, and then every 3 years. 




Infectious canine hepatitis, an adenovirus, can cause dogs’ a wide array of signs. We can see mild fever, low white blood cells, blood clotting problems, and death. However, we do not usually see it much in the US because of successful vaccination.

Hepatitis dog vaccination schedule 

Hepatitis vaccine is generally given as part of the combo vaccines and given at the same frequency as the other core vaccines. For example, the vaccine starts at 6 weeks of age, then every 3-4 weeks through a minimum of 16 weeks. It is boostered at 1 year, and then every 3 years 




A fatal viral disease, rabies, can be easily prevented by proper vaccination. Once contracted, there is no treatment, so prevention is our only option. Any mammal can develop this disease.

Vaccine campaigns in the US have been very successful against rabies. The dog variant (strain) of rabies was eradicated from the country due to a successful vaccination program in our pet dogs. 

However, rabies variants from bats, raccoons, skunks, mongoose, and fox still prevail in the US. So, we must continue to vaccinate to protect our pets and humans to ensure a healthy human-animal bond. 

Rabies dog vaccination schedule

Rabies vaccination for dogs provides protection from a deadly disease. Follow your state’s laws. Given first between 12-16 weeks of age and then at 1 year of age, it is administered every 1-3 years depending on the state or local government regulations. In most jurisdictions, this vaccine to be considered legal must be administered by a licensed veterinarian. 



Bordetella (KCV) and Parainfluenza (PI)

Bordetella bronchiseptica is a bacteria often generically referred to as “kennel cough”. This is one of nine diseases commonly seen causing an infectious tracheobronchitis, upper airway inflammation, that can occur in the collective “kennel cough” term. 

Coughing commonly shows first with dogs presenting with a characteristic, loud, whooping-like cough (almost a seal-like sound). Some dogs cough so hard they vomit, and owners may mistake coughing for gagging or choking. The cough is usually dry and non-productive. Most dogs have normal energy, and only a few have decreased appetites. 

Usually a self-limiting disease, most dogs do not require treatment. Some dogs and puppies may need medical treatment, while others simply need to wait it out. 

While coughing, dogs should be kept away from other dogs. This disease most commonly occurs in areas with close contact with other dogs, and it is very easily spread

Dogs groomed regularly, boarded, participate in doggy daycare, or even go to the dog parks frequently should be vaccinated against Bordetella.  

Parainfluenza virus is another bug that is part of the “kennel cough” disease group. Most of the time, it doesn’t cause significant disease by itself. Still, it can cause coughing. In many cases, it is given in combination with the Bordetella vaccine or as part of the combo vaccine, though not a true core vaccine.

Dog vaccination schedule for Bordetella (KCV) and Parainfluenza (PI)

Most veterinarians recommend the KCV/PI vaccine for all puppies and first-time adopted pets. You never know when you might need to board your pet, and what about puppy socialization classes or dog training classes? 

There are three versions of the KCV/PI vaccine: injectable (under the skin), intranasal (in the nose), or oral (in the mouth). 

The intranasal gets to the respiratory system right away, is considered the best protection, and has the fasted onset of protection. Vets may give this every 6 months or once a year. The injectable and oral versions vary depending on the brand. Talk to your vet about which is right for you and your pet.




Non-core vaccines are those additional vaccines recommended based on an individual dog’s exposure risks, including activities engaged in and susceptibility.



Lyme Disease Vaccine 

Borrelia burgdorferi is the bacteria spirochete that causes Lyme disease. Clinical signs can be non-specific and variable. They can include shifting leg lameness, sleepiness, exercise intolerance, decreased appetite, stiffness, muscle pain, and more. 

Many realize that ticks transmit this disease, but it has a complicated life cycle. Any dog outside in areas of the country where it is present is at risk. Your dog doesn’t have to be in the woods playing, and you do not have to have deer readily evident in your area for your dog to be exposed. All you need are squirrels and other small critters nearby to drop the ticks in the area your dog frequents. In high Lyme areas such as the NE part of the US, among other regions, vaccination in addition to monthly tick prevention helps lessen the chance of disease. 

Lyme disease dog vaccination schedule 

Two boosters 3-4 weeks apart are required initially, then vaccines are boostered annually for at-risk dogs. 




Leptospirosis, AKA lepto, is a zoonotic disease. Like the rabies virus, this bacteria threatens public health because it is infectious to people and other animals. 

These bacteria transmit via the urine of wildlife. So, licking the ground where an infected animal walked is sufficient for transmission. We used to think animals who were out in the woods, in nature, were most susceptible, but exposure and cases now commonly occur in large cities countrywide, including from Philadelphia to Los Angeles.5,6

Do vets recommend leptospirosis vaccine?

Many veterinarians treat this as a core vaccine because of many pets’ public health risks and high exposure risks. It can cause liver disease, kidney disease, muscle pain, shifting leg lameness, and more. The disease can be life-threatening or cause permanent damage and subsequent life-long disease, so vaccination is key to prevention. 

The vaccines out there now for this disease are generally safe and effective. A 4-serovar leptospirosis vaccine is recommended, protecting against 4 of the 5 strains out there vs. a 2-strain version. 

Historically, this vaccine has been controversial because it was the most seen to cause vaccine reactions. It still can lead to vaccine reactions. However, mild reactions can be prevented by a dose of Benadryl before administration. Even little breed dogs can receive it safely in most cases. Talk to your veterinarian about your dog’s risk to determine if this vaccine is warranted for your dog.

Lepto dog vaccination schedule

For at-risk animals, 2 lepto vaccine boosters 2-4 weeks apart start the vaccine and then yearly. It can be combined with DHPP to minimize the number of individual injections.



K9 Flu (Influenza) 

Two strains of the flu virus affect dogs exclusively, and it is another disease in the “kennel cough” complex. While not contagious to people, dogs exposed to these viral strains, H3N8 and H3N2, can have mild illness or more life-threatening severe pneumonia. Common signs include coughing, decreased appetite or energy, and sometimes fever. More severe cases can include respiratory distress or even death.

Exposure environments include grooming, daycare, and boarding. A vaccine that vaccinates against both strains is now recommended by the American Animal Hospital Association (AAHA) and other professional entities.

K9 Flu dog vaccination schedule

Two vaccines 2-4 weeks apart for at-risk animals to start the vaccine and then yearly.



At what age do we start puppy vaccines?

What is a puppy’s vaccine schedule? 

Puppies are usually vaccinated by a breeder or rescue at 6 weeks of age. They should receive core vaccines (DHPP) every 3-4 weeks until they are a minimum of 16 weeks. Usually 4 total vaccines initially, then they will get a booster at 1 year of age, then every 3 years.

The Rabies vaccine is licensed to be given at 12 weeks or older, but each state varies with specific rabies laws. So, most dogs will get their first rabies shot between 12-16 weeks of age, at 1 year of age, and then every 1-3 years, depending on the state of residence and legal requirements. 

Non-core vaccine schedule depends on individual pet risks and practice protocols.

After that time, how frequently dogs are vaccinated varies with the vaccine and the pet and other factors, including age, lifestyle, travel behaviors, and primary geographical location. 



Common dog vaccine side effects2,3

When your dog goes home after a vaccine, you may see some sleepiness, soreness, or decreased play. There may be swelling around the injection site for a few days or even longer or a low-grade fever. All of these signs are considered acceptable side-effects. Remember your last flu vaccine, or if you had a COVID shot, man, your arm may have been sore for several days, especially if you brushed up against the spot. 



Dog vaccination aftercare 

To minimize soreness and vaccine reactions, after the vet visit, let your pet rest. Avoid strenuous exercise and leash walk briefly rather than going for that 3-mile hike after a vaccine. 

Please let your veterinarian know if you notice any abnormalities, including limping, decreased appetite, vomiting, diarrhea, or other abnormalities occur. Do not give any over-the-counter human medications, even if you think your pet is painful, as many are toxic to dogs. Contact your veterinarian. 



Abnormal dog vaccine reactions

Sometimes allergic reactions happen. 

Signs of an allergy to a given vaccine can include sudden onset of vomiting and or diarrhea, hives (bumps), itching/rubbing at the face, muzzle, or other body parts, swelling of the face or head, or rarely collapse, trouble breathing, seizures, or death. 

Suppose any of these signs occur within 0-72 hours after vaccine administration. In that case, a veterinarian should assume it is because of the given vaccine. Contact your veterinarian immediately if your pet has trouble breathing or shows other signs above. If it is after hours, bring your pet to an emergency center asap. While usually not life-threatening, it can be for a rare dog, and getting prompt emergency treatment could save your dog’s life. 

Remember, the number of dogs with an actual anaphylactic (life-threatening) reaction is rare compared to the millions of dogs vaccinated over the years and the millions protected from deadly diseases. 



Do small breeds have higher rates of vaccine reactions? 

Some veterinarians appreciate more allergic reactions or, in general, more even mild vaccine reactions in smaller breed dogs. This often occurs when more than one vaccine is given at a time. Simply separating vaccines by 2 weeks, giving one at a time, is usually sufficient to prevent mild effects. 

Talk with your veterinarian about a plan if you have a small breed dog. If the dog has no issues with multiple vaccines at a time, there is no reason why vaccines cannot be given this way. 

However, if you space vaccines out, they need to be given a minimum of 2 weeks apart to allow a full immune response to develop after each vaccine.



When not to vaccinate a dog? 

There are some circumstances where a dog should not be vaccinated. These include

  • Dogs with previous severe reactions (anaphylactoid reactions such as severe vomiting, diarrhea, collapse, or breathing trouble)
  • Animals with immune-mediated diseases
  • Dogs on immunosuppressive medications such as steroids
  • When sick with another illness that is not controlled by medications
    • Skin and other ailments should be treated before vaccinating.
    • Vaccines require an intact immune system. So, any underlying disease could impair the dog’s ability to mount a proper response, lessening the vaccine’s benefits and may increase the risk of a vaccine reaction. 
  • Animals with cancer



What about dog blood titers instead of vaccinations? 7

Some may have heard mention of getting blood levels drawn for various diseases in lieu of getting the dog a vaccine. Veterinarians decide on vaccination strategies based on evidence-based medicine. While there are some guidelines on checking titers for distemper, parvovirus, and rabies, how this translates to protection from disease is unclear. Additionally, a rabies titer is not legally accepted in place of a vaccine.

However, a titer may be considered when vaccines are contraindicated, such as those pets with cancer. 



What should I know about dog vaccines? 

  • Vaccines never protect 100% from all diseases, but illness is usually much less severe even if it occurs and leads to a healthier outcome.
  • Some vaccines protect better than others.
  • Some vaccines are needed annually, while others may be given every 3 years or less frequently
  • Some vaccines are core and should be given to all pets
  • Never allow your vet to tell you a “partial” dose of a vaccine will help minimize reactions. Vaccines are designed by dose, not based on your pet’s size. Giving only a part of the vaccine will not lead to a protective response, and for the rabies vaccine, it is not legal to give a half-dose.
  • Rabies is required by law in most of the US.
  • If your dog goes outside to go to the bathroom at any time, the risk for infectious diseases exists. Unless your dog never sets foot outside, your dog is not an “indoor dog” and should be vaccinated.
  • Living in the city doesn’t mean your pet is safe from diseases like leptospirosis or Lyme disease


Do-it-yourself dog vaccinations

Do-it-yourself dog vaccinations are not recommended. While relatively easy to give, vaccines require some skill and finesse to not stress the pet, ensure cooperation and acceptance, and administer it correctly. 

Some vaccines will not be accepted legally or by entities when traveling from one state into another or internationally unless administered by a veterinarian. 

Finally, not all vaccine brands are created equal. Your veterinarian should keep up with the most up-to-date scientific evidence. Factors such as the best type of vaccine (how it triggers the immune system to provide protection) and the side effects and other components play a role in vaccine selection.



How much do dog vaccines cost?

If vaccination costs concern you, you can always choose a vaccination clinic or discounted programs offered by local shelters or local groups. Sometimes you have to call around. Vaccine and appointment costs vary depending on where you live. What type of veterinary practice you choose or if you choose a low-cost vaccine clinic or vaccine fundraiser event will also affect the cost of immunizations. Vaccines can range in price from $20-30 per vaccine to upwards of $50 for 3-year vaccines. The visits’ cost also varies and could be anywhere from $50-100. 



What to remember when scheduling a dog vaccine appointment

Do not schedule a vaccine appointment with your vet or even a vaccine clinic if your pet shows any signs of illness. Suppose your dog demonstrates coughing, sneezing, nasal discharge, skin or ear infections, or other problems. In that case, these pets shouldn’t be vaccinated and should be seen by a primary care veterinarian. Vaccines need intact immune systems to function correctly. Even if it is “just” an ear infection, your pet shouldn’t be vaccinated. Medications and the disease state itself could affect the pet’s immune system’s ability to mount a proper response to the vaccine. If exposed to the disease in the future, they may not be fully protected. Additionally, if they are already feeling under the weather, you know vaccines can make you feel funny and off. We don’t want to compound any discomfort unnecessarily. 



Dog vaccines protect against common diseases

If you are just getting a puppy or adopting a dog for the first time, even if you are an old pro and on your umpteenth dog, know that vaccinations are a part of owning a pet. 

Always factor in vaccine costs, veterinary appointment costs, and other factors in your decision to get a new dog. Know the disease risks in your area, your dog’s exposure level, and activities, and decide what vaccines are suitable for your pet with your veterinarian. 

By vaccinating your pet, you can protect your dog and preserve your human-animal bond. 



1. Ford R, Larson LJ, Schultz RD, Welborn LV. 2017 AAHA Canine Vaccination Guidelines*. Published online 2018. Accessed January 20, 2022.

2. AKC Staff. A Complete Guide To Puppy Vaccinations. American Kennel Club. Published January 1, 2022. Accessed January 20, 2022.

3. Gollakner R, Ward E. Vaccines For Dogs | VCA Animal Hospitals. VCA Animal Hospitals. Accessed January 20, 2022.

4. The Centers for Disease Control and Prevention (CDC). Wildlife Reservoirs for Rabies. Centers for Disease Control and Prevention. Published January 14, 2020. Accessed January 20, 2022.

5. County of Los Angeles Public Health. Leptospirosis in Dogs in Los Angeles County. County of Los Angeles Public Health. Published August 2, 2021. Accessed January 21, 2022.

6. White AM, Zambrana-Torrelio C, Allen T, et al. Hotspots of canine leptospirosis in the United States of America. Vet J. 2017;222:29-35. doi:10.1016/j.tvjl.2017.02.009

7. American Animal Hospital Association (AAHA). Interpreting antibody test results. AAHA. Accessed January 20, 2022.

Erica Tramuta-Drobnis, VMD, MPH, CPH
Erica Tramuta-Drobnis, VMD, MPH, CPH

Erica is is an experienced emergency and general practice veterinarian with (17+ years), currently working in emergency and critical care. She is the founder of ELTD One Health Consulting, LLC and a veterinary and public health writer, researcher, and consultant.