Do Dogs Really Need the Lepto Vaccine?

Dogs are susceptible to many diseases, but thankfully, vaccines can help prevent — or at least decrease the severity of — illness. Some vaccines are recommended for all dogs, regardless of the pups’ exposure risks, and these vaccines are called core vaccines. 

The leptospirosis vaccine is one core vaccine that can help prevent a serious disease caused by the Leptospira bacteria. Leptospirosis, commonly known as lepto, can be easily spread in the environment and cause a variety of symptoms, including serious kidney and liver damage. Understanding why the lepto vaccine is important to your dog will help you keep them healthy.

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What is Leptospirosis?

Leptospirosis is a bacterial infection caused by the Leptospira bacteria. There are more than 250 serovars of it, which can infect wildlife, people, and dogs. The bacteria cause dogs of all ages, sizes, and breeds to become sick. And while some will only experience mild symptoms, others can experience severe issues such as liver failure.

Historically, the lepto vaccine was only recommended for dogs regularly exposed to wildlife and outdoor water sources. With more research on this disease and its numerous serovars, it has been determined that even dogs living in cities are at risk of contracting it. This is because the bacteria can be easily spread by small rodents, like mice, which are found even in urban environments.

The lepto vaccine can be given independently or as part of the DHLPP combination vaccine. So if you are concerned about your dog having to get another poke at their annual vet visit, there’s no need to be worried.

What is the lepto vaccine schedule?

The lepto vaccine is a core vaccine, meaning that it’s highly recommended that all dogs get it. At a puppy’s first vet visit, your vet will discuss their core vaccine schedule. Puppies should be at least 12 weeks old when they begin their lepto vaccine schedule, which will include two vaccines, two to four weeks apart. A year after that, the lepto vaccine should be boosted.

Unlike some other core vaccines, which are only administered every three years after the initial booster, your dog will need the lepto vaccine every year. If you are unsure of your new dog’s medical records, your vet will recommend they receive two vaccines, two to four weeks apart, unless you prefer to check your dog’s lepto titer.

Related article

What Vaccines do Dogs Need?

Yes, you need to vaccinate your dog. Consider this your guide to their must-have vaccines, the optional ones, as well as vaccine schedules.

How does the lepto vaccine work?

The lepto vaccine exposes your dog to a very small or inactivated amount of the Leptospira bacteria. This controlled exposure stimulates your dog’s immune system to produce antibodies that will recognize and fight off the disease if your dog is exposed to it.

Since there are more than 250 serovars of Leptospira, there is no vaccine to protect your dog from all of them. Still, vaccines contain the four serovars that are thought to commonly infect dogs. These vaccines are called tetravalent lepto vaccines, or lepto four-way vaccines, and protect your dog against the Canicola, Icterohaemorrhagiae, Grippotyphosa, and Pomona serovars of the Leptospira bacteria.

Symptoms of leptospirosis

Leptospirosis can cause an array of symptoms: a decrease or loss of appetite, belly pain, lethargy, diarrhea, vomiting, yellow skin and gums, dehydration, weight loss, drinking and peeing more than usual, leg stiffness or pain, and difficulty breathing. If left untreated, kidney failure, liver failure, and even heart damage can occur in dogs infected with leptospirosis. In severe cases, this disease can be fatal.

Potential risks and side effects

Serious side effects from vaccines, including those for lepto, are rare. But temporary soreness at the injection site and some sleepiness are not uncommon. Vomiting, diarrhea, hives, and facial swelling are less likely to occur and indicate a vaccine reaction.

If your dog experiences these symptoms after vaccination, contact your veterinarian immediately. But if you are worried that your dog may have a vaccine reaction, it is best to proactively stay at the vet’s office for 30 minutes after vaccination to ensure your dog doesn’t experience any issues.

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Assessing the need for the lepto vaccine

Since lepto is a core vaccine, it is recommended for all dogs. Despite this blanket recommendation, it’s normal to want to assess how your specific dog will benefit from it, especially because this inoculation wasn’t always considered a core vaccine.

But Leptospirosis can be a life-threatening disease, so if you don’t think your dog should get the vaccine, you should reconsider. If your dog is diagnosed with lepto, you are not only at risk for contracting the disease yourself, but you may also need to hospitalize your dog so they can receive isolated treatment.

The thought of your dog being seriously sick is hard enough without having to think about the costs of leptospirosis treatment. It’s simply easier, cheaper, and safer to have your dog vaccinated. If cost is a factor, it’s important to note that many vets offer payment plans. Alternatively, you can consider pet insurance or look into other ways to get help with veterinary bills.

Questions to ask your veterinarian

If you’re still not convinced your dog can benefit from receiving the lepto vaccine, bring your questions to your vet. Be sure to ask them about any concerns you may have regarding potential side effects, how often your dog needs to be vaccinated for lepto, and where your dog will be poked with the vaccine (so that you can be aware of any soreness at the injection site). If you’d like your dog to receive the lepto vaccine separately from the DHPP combination vaccine, this is also an option you should ask your vet about.

Preventing leptospirosis

The best way to prevent leptospirosis is by vaccinating your dog; it will significantly diminish their chances of getting severely ill. You can also take additional steps to further reduce their exposure risk.

• Provide your pet with fresh water: When outside, don’t allow your dog to swim in or drink from ponds or other stagnant, slow-moving, or contaminated water.

• Ensure your dog stays away from wild animals: Keep your dog away from livestock and wildlife, including animal carcasses.

• Consider pet prevention: Pest prevention is also helpful for decreasing leptospirosis in your home, but be sure that your rodent eradication plan doesn’t also harm your dog or other pets.

Commonly asked questions

How often does my dog need a booster for the lepto vaccine?

Research has shown that the tetravalent lepto vaccine can protect your dog from the disease for 12 to 15 months. This means after your pup’s initial two-vaccine series, they should receive a booster shot each year to ensure they remain protected. If you would prefer to check whether or not your dog has adequate protection against lepto before vaccinating, a blood titer test is available for an additional cost.

Is the leptospirosis vaccine necessary if my dog is mostly indoors?

Yes, the leptospirosis vaccine is recommended for all dogs, even if they are mostly indoors. Lepto can be spread through rodents that get into your home as well as through outdoor puddles. So even if your dog is mostly indoors and never around wildlife or livestock, they can still be exposed.

How effective is the lepto vaccine in dogs?

Research shows that the lepto vaccine is more than 80 percent effective in preventing clinical disease in dogs, so it is very effective. Considering how easy it is for the bacteria to infect your dog, and how serious the symptoms can be, vaccination should be a no-brainer. Preventing disease is easier and cheaper than treating it — and can ultimately protect your dog’s life.

How is the vaccination schedule for dogs determined?

The current vaccination schedule for the lepto vaccine and other vaccines is based on research. This research looks at how long antibodies exist in most dogs after vaccination. For lepto, the tetravalent vaccine shows at least 12 months of immunity against four serovars of lepto after an initial two-vaccine series.

Can a dog give lepto to a person?

Yes, a dog can give lepto to a person. Leptospirosis is zoonotic, so it can be spread from your dog to you. For this to occur, the bacteria must enter the body through your eyes, nose, mouth, or open wound. This most commonly happens if you get lepto-infected pee on your hands and have an open cut or wipe your face, or if the pee is accidentally splashed into your face.

How is lepto treated?

If your dog is diagnosed with lepto, at least two weeks of antibiotics and symptomatic treatment will be needed. Depending on how severe the infection is, your dog may need IV fluids and other medications while hospitalized. Additionally, isolation to prevent the spread of the disease is recommended.

Common myths about the lepto vaccine

There are many myths about many pet-related things, including the lepto vaccine. One common myth is that the vaccine isn’t effective — but based on research, this is simply not true. Another myth is that small dogs don’t need the lepto vaccine because they aren’t at risk for it. This is untrue since lepto is spread through the urine of livestock and wild animals, so if your dog goes outside, they are at risk.

According to research, dogs weighing less than 15 pounds are the most likely to be diagnosed with a leptospirosis infection. Your veterinarian can help dispel any other myths you may have heard to ensure you make decisions based on facts and not fear.

References

AAHA. “Recommendations for Core and Noncore Canine Vaccines.” AAHA, 17 Aug. 2022, www.aaha.org/resources/2022-aaha-canine-vaccination-guidelines/recommendations-for-core-and-noncore-canine-vaccines.

AVMA. “Leptospirosis in Dogs | American Veterinary Medical Association.” Www.avma.org, 2025, www.avma.org/resources-tools/pet-owners/petcare/leptospirosis. 

Bergmann Esteves, Stephanie, et al. “Efficacy of Commercially Available Vaccines against Canine Leptospirosis: A Systematic Review and Meta-Analysis.” Vaccine, vol. 40, no. 12, Mar. 2022, pp. 1722–1740, doi.org/10.1016/j.vaccine.2022.02.021. 

Bond Vet. “Leptospirosis Vaccine for Dogs: What It Is and How It Works.” Bond Vet, 23 Dec. 2022, bondvet.com/b/leptospirosis-vaccine-for-dogs.

“Canine and Feline Vaccine Panels and Serological Responses to Vaccination.” The College of Veterinary Medicine at Michigan State University, cvm.msu.edu/vdl/laboratory-sections/virology/canine-and-feline-vaccine-panels. 

CVPM, Sandy Walsh, RVT. “Vaccination Overview: Leptospirosis.” Today’s Veterinary Practice, 22 June 2021, todaysveterinarypractice.com/preventive-medicine/vaccination-overview-leptospirosis. 

Lee, H S, et al. “Signalment Changes in Canine Leptospirosis between 1970 and 2009.” Journal of Veterinary Internal Medicine, vol. 28, no. 2, 2014, pp. 294–9, www.ncbi.nlm.nih.gov/pubmed/24372922.

Sykes, Jane E, et al. “2023 Updated ACVIM Consensus Statement on Leptospirosis in Dogs.” Journal of Veterinary Internal Medicine, vol. 37, no. 6, 20 Oct. 2023, pp. 1966–1982, doi.org/10.1111/jvim.16903. 

Sykes, Jane, and Krystle Reagan. “Leptospirosis in Dogs: Diagnosis, Treatment, and Management.” Today’s Veterinary Practice, 22 Aug. 2019, todaysveterinarypractice.com/infectious-disease/diagnosis-and-treatment-of-leptospirosis-in-dogs.