What is Leptospirosis and Why You Should Vaccinate Your Dog Against It

At We Care More Animal Rescue, we know that your pet’s health is your top priority. One of the most important — and often overlooked — steps in keeping your dog safe is vaccinating against leptospirosis. This potentially deadly bacterial infection poses a serious risk, especially in warm, wet climates like South Florida. Here's what every responsible pet owner should know.

What Is Leptospirosis in Dogs?

Leptospirosis is a highly contagious bacterial disease caused by Leptospira bacteria. It can affect dogs, humans, and other animals, and is most commonly spread through contact with infected urine or contaminated water, such as puddles, ditches, or standing rainwater — something we see a lot of during the rainy season in Florida. Rats and farm animals are common carriers of leptospirosis, while cats are rarely affected.

An infected animal can shed leptospira bacteria in urine and other body fluids, contaminating the environment. The bacteria can survive in water or soil for weeks or even several months, increasing the risk of exposure. For example, a dog might become affected by sniffing or drinking from a puddle contaminated with the body fluids of an infected animal.

While it may sound rare, leptospirosis is on the rise, even in suburban neighborhoods and city parks. All it takes is one curious sniff or sip from a contaminated puddle to put your dog at risk.

Why Leptospirosis Is So Dangerous

Leptospirosis doesn’t just cause mild symptoms — in fact, it can lead to serious illness, organ failure, and even death if left untreated. The infection primarily targets the kidneys and liver, and in some cases can also cause lung complications or internal bleeding.

Leptospira bacteria enter the body through cuts or breaks in the skin or through mucous membranes, and once inside, they can spread to multiple organs and tissues.

Leptospirosis typically progresses in two phases. The first, called the leptospiremia phase, occurs when the bacteria are present in the bloodstream. During this phase, dogs often develop flu like symptoms such as fever, muscle pain, and lethargy, which usually appear suddenly and last about a week. The second phase, known as the immune phase, begins as antibodies develop in the blood and the bacteria migrate to organs like the kidneys. This phase can lead to more severe illness, including complications such as Weil's syndrome.

In most cases, leptospirosis is mild and self-limiting, but some dogs can become very sick and develop severe illness that requires intensive treatment.

Common Symptoms of Leptospirosis in Dogs:

Keep an eye out for these signs:

Sudden fever
Vomiting (sometimes with blood)
Loss of appetite
Jaundice (yellowing of eyes or skin)
Lethargy or weakness
Increased thirst or urination
Diarrhea
Muscle pain or stiffness
Coughing or breathing issues
Trouble breathing
Red or swollen gums
Shivering or reluctance to move
Bloody vaginal discharge
Swollen legs or fluid in the abdomen

Because these symptoms mimic many other illnesses, early diagnosis and treatment are key. If you suspect leptospirosis, contact your veterinarian immediately.

Dog Breeds at Higher Risk

Not all dogs face the same level of risk when it comes to leptospirosis. Certain dog breeds, especially those with active outdoor lifestyles, are more likely to encounter infected animals or contaminated water. According to the American Veterinary Medical Association, breeds such as Alaskan Malamutes, American Bulldogs, and American Foxhounds are particularly susceptible due to their natural instincts for herding, hunting, or exploring. Dogs that love swimming, like Labrador Retrievers and Golden Retrievers, also face increased risk, as they are more likely to come into contact with water sources that may harbor leptospira bacteria. If your dog belongs to one of these breeds or spends a lot of time outdoors, it’s especially important to be vigilant about exposure and to keep up with recommended vaccinations to protect against leptospirosis.

Is Leptospirosis Contagious to Humans or Other Pets?

Yes — leptospirosis is a zoonotic disease, which means it can spread from animals to humans. While the risk of transmission from your dog to your family is low with proper hygiene, exposure to your pet’s urine can transmit the disease.

It is rare for humans to spread leptospirosis to each other, as most cases occur from contact with infected animals or contaminated environments rather than person-to-person transmission.

To reduce the risk:

Wear gloves when cleaning up accidents
Disinfect any areas where your dog has urinated
Wash your hands after handling your pet
Keep infected pets away from standing water and areas where other pets or people may walk

Long-Term Effects of Leptospirosis in Dogs

Leptospirosis can have serious, lasting consequences for dogs if not treated quickly. Beyond the initial illness, the disease can cause severe symptoms such as kidney damage, liver failure, and even internal bleeding. Some dogs may develop persistent muscle aches, ongoing jaundice, or chronic fatigue, all of which can greatly affect their quality of life. In the most severe cases, these complications can be life-threatening. Fortunately, with prompt veterinary care and treatment—often involving antibiotics like doxycycline—many dogs can recover fully. However, some pets may require extended hospitalization and supportive care to manage the illness and prevent permanent damage. Early intervention is key to minimizing the risk of long-term effects and helping your dog return to a healthy, active life.

How Is Leptospirosis Treated?

Once diagnosed, veterinarians use blood tests, urine tests, and other tests to confirm leptospirosis. In severe cases, diagnostic tools such as chest x ray, ct scan, or other imaging may be used to assess organ damage.

To treat leptospirosis, antibiotics such as doxycycline or penicillin derivatives are typically prescribed. In severe cases, your dog may require IV fluids, hospitalization, and supportive care to recover.

But here’s the truth: Treatment can be difficult and costly — and prevention is far easier.

The Best Protection: Vaccinate Your Dog

The most effective way to protect your dog from leptospirosis is through vaccination.

The American Animal Hospital Association (AAHA) recommends annual leptospirosis vaccinations for most dogs, including those in urban and suburban areas. Many dog owners still mistakenly believe it’s a “rural” disease — but that’s no longer true. Vaccination is recommended for every breed, regardless of lifestyle or environment.

At We Care More Animal Rescue, we’ve seen the benefits of this vaccine firsthand. Vaccinated dogs are far less likely to contract or spread the disease, even in high-risk environments.

Is the Leptospirosis Vaccine Safe?

Yes! The vaccine is safe and effective, and is often included in your dog’s annual wellness visit. If your pet hasn’t been vaccinated yet, contact your veterinarian today or speak with one of our staff members to learn more about scheduling a vaccination.

Regional Considerations: Is Your Area at Risk?

The risk of leptospirosis isn’t the same everywhere—it can vary widely depending on where you and your pets live. Regions with heavy rainfall, frequent flooding, or warm, humid climates are especially prone to outbreaks, as these conditions make it easier for leptospira bacteria to thrive in contaminated water and soil. In the United States, states like Hawaii, Florida, and Puerto Rico have seen higher rates of leptospirosis, particularly after storms or flooding events. Around the world, places like Southeast Asia face an even greater risk due to their tropical environments and increased exposure to infected animals. If you live in or travel to these high-risk areas, it’s crucial to take extra precautions—avoid letting your dog drink from or swim in standing water, and make sure their vaccinations are up to date. Staying informed about local risks can help you protect your pets from this potentially serious disease.

The Importance of Regular Check-Ups

Routine veterinary check-ups are one of the best ways to protect your dog from leptospirosis and other diseases. Regular visits allow your veterinarian to monitor your pet’s health, perform urine tests or other diagnostics to detect Leptospira bacteria, and catch any early signs of infection before severe symptoms develop. Your vet can also provide guidance on prevention, such as avoiding contaminated water and recommending the right vaccination schedule for your dog’s lifestyle and risk factors. For humans, regular check-ups with a healthcare provider are equally important, especially if you live in an area where leptospirosis is common or have frequent contact with animals. Early detection and treatment can make a significant difference in outcomes for both pets and people. By prioritizing regular check-ups, you’re taking a proactive step to reduce the risk of infection and ensure a healthier life for your entire family.

How Else Can You Prevent Leptospirosis?

In addition to vaccinating your dog:

Avoid letting pets drink from puddles or standing water
Keep your backyard and walking paths clean and free of rodent activity
Don’t allow your dog to roam in flood-prone areas or wildlife-heavy locations
Practice good hygiene after handling pets or cleaning up messes

Protect Your Pet — and Your Family

Vaccination is a simple, affordable step that can save your dog’s life and protect your family. As we continue through Florida’s rainy season, now is the perfect time to make sure your pet is protected.

At We Care More Animal Rescue, we care more — and that means promoting prevention through education and action.

Don’t wait until it’s too late. Call your vet today to schedule a leptospirosis vaccination, or reach out to us to learn how we can help.