Veterinarian vaccinating a dog.

Vaccinating your dog against dangerous diseases, such as rabies and distemper, seems like a no-brainer. But there’s recent evidence that some pet owners may be hesitating to get their dogs these and other standard shots.

“We know that pet owners seem to be asking more questions about what vaccines are appropriate and when,” says John de Jong, D.V.M., president of the American Veterinary Medical Association (AVMA).

The most recent rabies report from the Centers for Disease Control and Prevention found that the number of reported rabid dogs climbed nearly 14 percent between 2014 and 2015. Today, about 60 to 70 dogs in the U.S. get rabies each year from wildlife. The vast majority of these dogs have not been vaccinated.

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With some areas of the U.S. seeing growing numbers of unvaccinated children—largely because of the debunked idea that vaccines can cause autism—it’s possible that a generalized fear of vaccines might be spreading among clients of veterinary practices in some corners of the country.

Across the Atlantic Ocean, the British Veterinary Association earlier this year felt it was necessary to issue a press release correcting the idea—implied by a morning TV show in the U.K.—that vaccines could cause autism in dogs.

Stephanie Liff, D.V.M., owner of Pure Paws Veterinary Care in New York City, estimates that roughly 3 percent of the dog owners she sees are pushing back against vaccines. “The reasoning of clients varies, but it’s often without a scientific basis,” Liff says.

Here is what you need to know about the importance of getting your dog vaccinated, as well as which vaccinations you should get for dogs—and when.  

Why Pet Vaccination Is Important

Vaccination in pets is widely considered a public health success, just as it has been with people.

Take rabies. The disease kills 59,000 people around the world every year, largely because of transmission from dogs in countries where dog vaccination is not widespread, according to the AVMA.

Even in the U.S., the majority of animal rabies cases before 1960 were in domestic animals, according to the CDC. But today, thanks to the rabies vaccine, more than 90 percent of U.S. cases occur in wildlife, not pets—and human cases have plummeted from about 100 cases per year at the turn of the century to just one or two per year. (Many more people are exposed to the rabies virus each year but don’t come down with the condition because they get the human vaccine in time.)

“Because we vaccinate our animals, we don’t often see the diseases we’re vaccinating the animals for,” says Lori Bierbrier, D.V.M., a veterinarian and medical director of the Community Medicine program at the American Society for the Prevention of Cruelty to Animals. “I think sometimes people can get a false sense of security that these illnesses aren’t around and that they shouldn’t have to worry about them.”

But in reality, Bierbrier says, the bugs that cause these conditions are everywhere, even in urban areas.

Officials in New York City, for example, recently warned pet owners to keep dogs on leashes in Central Park because of a distemper outbreak in raccoons. (Read more about distemper below.)

“Many of these illnesses are life-threatening,” Bierbrier says, “so there’s so much to be said for an ounce of prevention. Just have your animal vaccinated, so you don’t have to worry about it.” 

The Right Vaccine Schedule

Most veterinary groups, such as the AVMA and the American Animal Hospital Association, recommend that all dogs get a suite of “core” vaccines (see below) as puppies and then at regular intervals as adults.

These are most often given at 8, 12, and 16 weeks; one year later; then every 3 years after that, says Michael Stone, D.V.M., a clinical assistant professor of internal medicine and small animal medicine at the Cummings School of Veterinary Medicine at Tufts University.

Once dogs reach adulthood, there are different opinions on how often they need vaccine boosters, Bierbrier says. Most dogs should be revaccinated every three years, though your vet may advise otherwise, depending on things such as your pup’s health, lifestyle, and vaccination history, and the vaccine manufacturer’s recommendations. If you have a rescue dog, you can also ask the organization or shelter what it recommends.

“Certain dogs in high-risk environments, such as those that are frequently boarded or are frequently exposed to stray animals, might benefit from having more frequent [vaccinations],” Stone says. “But that is at the discretion of the veterinarian. Every three years is adequate for the vast majority of pets.”

Bierbrier and Stone say there’s evidence that suggests that some vaccines may last longer than three years, but the science isn’t solid enough yet to change the recommendations. 

Core Vaccines

Here’s a guide to what the core vaccines protect against.

Distemper
Symptoms: Fever, nasal discharge, coughing, lethargy, reduced appetite, and vomiting. This is a highly contagious and often fatal disease.
How it spreads: Sneezing or coughing. Commonly found in wildlife such as coyotes, foxes, raccoons, skunks, wolves, mink, and ferrets.
Can humans catch it? No.
Note: The distemper vaccine is commonly grouped with the parvovirus, adenovirus-2 (hepatitis), and parainfluenza vaccines below.

Parvovirus
Symptoms:
Lethargy; loss of appetite; abdominal pain; bloating; fever or low body temperature (hypothermia); vomiting; and severe, often bloody, diarrhea. Dehydration can result after persistent vomiting and diarrhea; and damage to the intestines and immune system can cause septic shock. This disease is highly contagious and often fatal.
How it spreads: Dog-to-dog contact and feces.
Can humans catch it? No.

Adenovirus-2 (Hepatitis)
Symptoms:
Inflammation of the liver; dry, hacking cough; retching; coughing up white, foamy discharge; eye inflammation; and mild fever. In severe, often fatal cases, symptoms can include higher fever, depression, loss of appetite, abdominal pain, vomiting, diarrhea, swelling of the head and neck, and jaundice. Severe cases often occur in young puppies.
How it spreads: Dog-to-dog contact, feces, and urine.
Can humans catch it? No.

Parainfluenza Virus (Dog Flu)
Symptoms:
Soft, moist, or dry cough; nasal and/or eye discharge; sneezing; lethargy; fever; and sometimes loss of appetite. This condition is highly contagious, but most dogs recover. Some deaths from the H3N2 virus have been reported.
How it spreads: Coughing, barking, and sneezing.
Can humans catch it? No.

Rabies
Symptoms:
This inflammation of the brain and spinal cord can lead to fearfulness, aggression, excessive drooling, difficulty swallowing, staggering, paralysis, and seizures. This disease is often fatal.
How it spreads: Saliva, usually through the bite of an infected animal. It can lurk in bats, raccoons, skunks, and foxes—in cities and in rural areas.
Can humans catch it? Yes.
Note: Required vaccination frequency varies from state to state. (The AVMA maintains a helpful guide [PDF].)

Noncore Vaccines

Your veterinarian may recommend some additional vaccines, depending on your dog’s lifestyle and where you live.

If your dog is frequently boarded or groomed, for example, it might be vaccinated against Bordetella bronchiseptica (kennel cough). If you live in a wooded area with lots of ticks, hiking, and swimming, your vet may recommend vaccines against Lyme disease and Leptospira bacteria (a bacteria spread through animal urine, blood, or tissues that can cause fever, joint pain, and general malaise).

Are Dog Vaccines Safe?

Yes. The risk of a bad reaction is rare, according to Bierbrier at the ASPCA. And the potential ramifications of your pet coming down with the illness far outweigh the slight chance that your dog will experience any serious side effects.

Mild side effects to be expected after vaccination, according to the AVMA, include irritation or swelling at the injection site, mild fever, diminished appetite, low energy, sneezing, or mild coughing. With an intranasal vaccine, such as some versions of the dog flu or bordetella vaccine, your pet may have a “snotty nose” two to five days after getting the vaccine.

As with any vaccination (including those in humans), there are even rarer risks of an allergic reaction. If you notice persistent vomiting or diarrhea; itchy, bumpy skin (“hives”); swelling around the face, neck, eyes, or muzzle; severe coughing; difficulty breathing; or collapse, take your dog to the vet immediately, the AVMA says. These warning signs of a life-threatening allergic reaction could occur minutes to hours after vaccination.

Dogs with certain medical conditions might need to avoid vaccination because it could trigger a bigger immune response that might attack parts of the body. Discuss the appropriate vaccination approach with your vet if your dog has conditions such as cancer, an active infection, or an autoimmune disease, such as canine lupus or rheumatoid arthritis, Bierbrier and Stone say. In some cases, it may be better to avoid vaccination or delay until the dog is better.