Skip to main content
Blog Hero Image

Leptospirosis Vaccine for Dogs: What It Is and How It Works

Leptospirosis—or “Lepto” for short—is a bacterial disease that can cause serious illness in both dogs and humans, and even be fatal. While this may be scary, a simple vaccination is all it takes to protect many dogs.

Read on to learn more about Leptospirosis in dogs, which pups are most at risk, and whether canine Leptospirosis vaccination might be a good option for your furry friend.

What Is the Leptospirosis Vaccine for Dogs?

Leptospirosis is a disease caused by bacteria—more specifically, one of several types of Leptospira bacteria. These bacteria are transmitted through the urine of other infected animals, which can then contaminate standing water, vegetation, or soil. 

Dogs become infected by consuming or swimming in contaminated water, through contact with contaminated soil or vegetation, or via direct contact with other infected pets including shared food or bedding. Transmission is also possible via exposure on mucus membranes (mouth, nose, or eyes) or cuts in the skin. In other words, wherever Leptospira bacteria are found, there are many ways for dogs to be exposed and become infected.

Leptospirosis infection can cause general symptoms of illness, such as loss of appetite, fever, lethargy, or stomach upset. Initially, these clinical signs might resemble many other illnesses. You might also notice jaundice (yellow tone to the skin and eyes) or changes to your dog’s urination. 

More severe forms of the disease can result in hemorrhage or bleeding, including bloody vomiting and diarrhea. And Leptospirosis can quickly progress to kidney or liver failure, and even cause death.

The Leptospirosis vaccine is designed to protect against this disease in dogs.

How Does the Leptospirosis Vaccine Work?

The Leptospirosis vaccine in dogs works the same way that other vaccinations do. It introduces the dog’s body to a small, inactivated quantity of the bacteria. This helps safely train the dog’s immune system to recognize and fight against Leptospira bacteria should your pup ever encounter the infectious form.

There are many different types of Lepto bacteria out there. However, only a handful account for the vast majority of disease in dogs in the United States. Typical Leptospirosis vaccines recommended by veterinarians offer protection against four of the most common serovars, or subtypes, of Leptospirosis. 

Unfortunately, it’s not possible to protect against every Leptospirosis strain in one vaccine. But the lepto vaccine provides a great deal of protection against four prevalent strains of the disease.

Should Your Dog Get the Leptospirosis Vaccine?

Lepto can be found in nearly all environments in the US, including urban, rural, and everything in between. It’s more common in warm, humid or wet environments, but it’s been found across the country. In more rural or wooded places, the disease can be transmitted by wildlife and livestock, especially in dogs who enjoy swimming in lakes or ponds. However, living in the city doesn’t eliminate the risk, since rodents like mice and rats are common carriers of the disease.

Another very important consideration is that Leptospirosis is contagious to humans!

Humans can be exposed the same way dogs can, such as from contaminated water. But Lepto is also a zoonotic disease, meaning it can be transmitted from an infected animal (in this case, a beloved family dog) to humans. In fact, the Centers for Disease Control recommends dogs be vaccinated against Leptospirosis to reduce the potential health risk to people.

Due to the widespread and serious nature of the disease, along with the fact that it can affect both humans and dogs, many veterinarians routinely recommend the Leptospirosis vaccine.

However, as with any vaccination or medication, it’s important to discuss this with your veterinarian on a case-by-case basis. According to the recommendations of the American Animal Hospital Association, Leptospirosis isn’t considered a “core” vaccine, or one that is recommended for all dogs (like rabies or parvovirus vaccines). However, Lepto might be considered a core vaccination locally in areas with high prevalence or following an outbreak. Your veterinarian can help you with this decision based on your dog’s individual risk level.

How Often Do Dogs Need the Lepto Vaccine?

The Leptospirosis vaccine in dogs requires yearly boosters to maintain its effectiveness. It’s possible to receive the vaccine on its own, or in combination with a dog’s DAPP (distemper, adenovirus, parvovirus, and parainfluenza virus) vaccine.

Following the very first dose of the vaccine, a dog should receive a Lepto booster in 2-4 weeks. This initial booster schedule might be repeated if a dog has had the vaccination in the past but is very overdue for their annual booster.

The Leptospirosis vaccine can be given to puppies, most commonly beginning at 12 weeks of age and boosted at 16 weeks of age. After that, yearly boosters are recommended.

What Are the Potential Risks and Side Effects?

As with any vaccine or medication, it’s possible for dogs to have a reaction or side effect. Fortunately, modern vaccines are very safe. Serious side effects are uncommon, and most dogs do just fine. 

Most side effects are mild and go away after a few hours or a few days at the most. Most commonly, this includes a little soreness or mild swelling at the injection site, tiredness, decreased appetite, a mild fever, or mild stomach upset.

Although rare, it’s important to be aware of the signs of a more serious allergic reaction or anaphylactic shock. This could potentially include more severe vomiting or diarrhea, hives, facial swelling, breathing trouble, collapse, or loss of consciousness. While uncommon, any serious vaccine reactions require immediate veterinary care. 

Dogs who are at a higher risk for reactions or side effects include dogs who have had previous vaccine reactions, or dogs that are very small in size, especially under 5-10 lbs of body weight. Giving a lot of vaccinations at a single visit can also increase the risk in dogs who are sensitive.

If your dog falls into a higher risk category, your veterinarian might recommend giving a protective antihistamine prior to vaccination (check with your vet prior to giving anything to make sure it’s safe and appropriate for your pet) or dividing vaccinations into separate appointments so your dog doesn’t receive too many at any given visit. 

Need a vet? Book a visit.

Are There Alternatives to the Lepto Vaccine?

In some cases, such as for dogs who have had severe vaccine reactions in the past, a veterinarian might recommend skipping one or more vaccines. Unfortunately, this doesn’t eliminate the risk of infection. It’s a matter of weighing the risks and benefits for each individual dog.

For dogs who would benefit from minimal vaccination, your veterinarian might recommend measuring titers, a blood test that gives an idea of the levels of antibodies or protection your dog has against a certain disease. These can be rechecked on an annual basis, to determine when a dog’s protection is wearing off and when they need a booster. Unfortunately, this method isn’t always completely reliable. But it makes sense for some dogs who are sensitive to vaccines or have certain medical issues.

To some extent, a pet owner can change their dog’s lifestyle to minimize risk of Leptospirosis. Unfortunately, it’s not possible to eliminate the risk entirely if your dog goes outside at all, even just walking on city streets or in parks. But avoiding high risk situations—such as swimming in lakes or ponds near livestock—can at least take a dog out of a high risk group. Also, take measures to prevent rodent infestations. Avoid leaving out food or accessible trash cans that could attract wild animals.

Commonly Asked Questions About Leptospirosis in Dogs

What Is Leptospirosis and How Does It Affect Dogs?

Leptospirosis is a disease caused by Leptospira bacteria. It can cause general illness—like fever, lethargy, and digestive upset—as well as kidney and liver failure. It can be fatal. Leptospirosis is also a health risk to humans, who can catch it from an infected dog.

How Do Dogs Get Leptospirosis? Is It Common?

On average, Leptospirosis isn’t a very common disease in dogs—possibly due to the effectiveness of widespread vaccination. However, it’s also not rare, and outbreaks are reported from time to time. Since the disease is widespread across the US and can be fatal, it must be considered when discussing preventive health for dogs. Dogs can get it from drinking or swimming in contaminated water, or simply from contact with soil or vegetation where livestock or wild animals have urinated.

Can I Get Leptospirosis from My Dog?

Yes. Unfortunately, dog owners can catch the disease from their beloved pup. This can happen when a dog is sick. Some dogs also become carriers, shedding the bacteria in their urine with hardly any symptoms of illness or following recovery. If you suspect your dog could have Leptospirosis, it’s important to seek veterinary care as soon as possible. Avoid contact with your dog’s urine (at the very least, wear gloves, thoroughly clean any soiled areas in the home, and wash your hands frequently), and ask your vet for additional advice.

Fortunately, Leptospirosis is treatable with antibiotics. However, the disease can be serious. Many infected dogs require supportive or intensive care at a hospital to survive, and some pups pass away even with medical care. 

Early diagnosis and treatment gives the best prognosis. It’s also important to finish all antibiotic courses and follow up with your veterinarian, even after your pup is feeling better, to reduce the risk of them becoming a “carrier” that sheds the bacteria.

A little prevention goes a long way. A simple vaccination provides protection for most pups, whether your pup is more of a homebody or more of an adventurous explorer. 

Any questions or concerns? Call us, schedule a telehealth appointment, or come in for urgent care today. We’ll be happy to answer any questions, or get your pup scheduled for vaccinations.

Better care,
Right when you need it

Book a visit