Can Indoor Dogs Get Leptospirosis?

Leptospirosis is an infectious disease caused by spiral-shaped bacteria called Leptospira that spreads from animals to humans. Leptospirosis is considered a zoonotic disease, meaning it can be transmitted from animals to humans. The bacteria spreads through the urine of infected animals and can contaminate soil or water. Humans can become infected through direct contact with urine or contaminated soil or water. The most common route of transmission for humans is contact with water or soil that has been contaminated by the urine of infected animals (

Leptospirosis Transmission

Leptospirosis is typically transmitted through contact with the urine of infected animals (1). The bacteria that causes leptospirosis can survive for months in water and moist soil contaminated with infected urine (1). As a result, outdoor water sources like lakes, streams, and puddles pose a high risk of exposure for dogs (2).

However, indoor dogs are not completely protected from leptospirosis. The bacteria can be tracked inside on the fur or feet after contact with infected urine outside (3). Indoor dogs may also be exposed through contact with rodents or other infected wildlife that find their way indoors (2). Sharing water bowls, food bowls, or bedding with an infected dog can also spread the bacteria (3). So while the risk is lower for indoor dogs, leptospirosis transmission is still possible without going outside.




Infection Sources Indoors

Leptospirosis is spread through the urine of infected animals, which can contaminate food, water, soil, and environments (Centers for Disease Control and Prevention, 2022). Rodents like rats and mice are common carriers of Leptospira bacteria and can transmit it through their urine (Mwachui et al., 2015). If infected rodents find a way into the home, they can contaminate surfaces, food bowls, water bowls, toys, or bedding through their urine.

In one study, having an indoor water source was found to be protective against leptospirosis compared to gathering water from outdoor sources, likely because it reduced exposure to contaminated outdoor sources (Ashford et al., 2000). However, indoor pets could still potentially be exposed through drinking standing water, eating contaminated food items, or contacting urine-soaked bedding material if infected rodents enter the home.

Preventing Exposure

Dogs can be exposed to the Leptospira bacteria from contact with infected rodents and their urine ( Preventing exposure is an important way to reduce the risk of dogs contracting leptospirosis. This involves keeping rodents out of the home and avoiding contact with rodents and their urine.

To prevent rodents from entering the home, inspect the foundation, walls, doors, and windows for any gaps or holes where rodents could get in. Use steel wool or caulk to seal up any entry points. Trim overgrown vegetation and brush near the home that could provide shelter for rodents. Place traps inside and outside to catch rodents. Store pet food in rodent-proof containers and clean up any spilled food right away.

When outdoors with your dog, avoid areas where rodents are frequently seen. Do not allow dogs to sniff, lick, or eat urine or droppings from potentially infected rodents. Supervise dogs when outside to prevent hunting and ingesting rodents. Fence in your yard to deter rodents and restrict your dog’s access ( With proper rodent control and limiting your dog’s exposure, you can reduce the chances of your indoor dog contracting leptospirosis.


Leptospirosis vaccines help prevent infection by stimulating the dog’s immune system to produce antibodies against the Leptospira bacteria. According to the VCA Animal Hospitals, there are four main types of Leptospira that vaccines protect against: Icterohaemorrhagiae, Canicola, Pomona, and Grippotyphosa.1 These vaccines do not provide complete immunity, but they are still highly recommended by veterinarians.

After the initial vaccination series of two doses 2-4 weeks apart, annual boosters are recommended to maintain immunity. Protection begins to decline after 6-12 months. Some veterinarians may recommend vaccinating twice a year for dogs at high risk. Duration of immunity can vary between dogs. Monitoring antibody levels with titer tests can help determine if more frequent vaccination is needed.2


Leptospirosis is diagnosed through blood testing. The main blood tests used are the DNA-PCR test and the microscopic agglutination test (MAT) [1]. The DNA-PCR test detects the bacteria’s DNA, while the MAT measures the level of antibodies produced by the dog in response to the infection. These tests allow veterinarians to confirm if a dog has leptospirosis.

It’s important to diagnose leptospirosis as early as possible, as prompt treatment can improve outcomes. Dogs with severe infection may need hospitalization and intensive care. Starting antibiotics and supportive therapies quickly in confirmed cases gives dogs the best chance of making a full recovery [2].


Treatment for leptospirosis typically involves antibiotics and supportive care. The sooner treatment begins, the better the chances are for recovery. Doxycycline is usually the first line antibiotic used, though penicillin may also be prescribed. These antibiotics help kill the bacteria and prevent complications from arising.

More severe cases of leptospirosis often require hospitalization. Supportive care aims to prevent organ damage and may include intravenous fluids, dialysis, respiratory support, and medication to control bleeding. With aggressive treatment in the hospital, most dogs can make a full recovery from leptospirosis.


With early detection and proper treatment, the prognosis for dogs with leptospirosis is generally good. According to the Cornell University College of Veterinary Medicine, the mortality rate for dogs that receive appropriate treatment is around 5-10% ( Most dogs show improvement within 2-4 days after starting antibiotic treatment. However, complete recovery can take 4 weeks or longer.

Dogs with severe kidney or liver damage may require intensive hospitalization and support care such as intravenous fluids and medication. These dogs have a higher mortality rate of around 20-30%. With aggressive treatment, many dogs can recover normal organ function, but some may be left with chronic kidney or liver disease (

Overall, early veterinary care greatly improves the chances of survival and full recovery from leptospirosis in dogs. Monitoring for potential organ damage and starting antibiotics at the first signs of illness are key to optimizing the prognosis.

Prevention Tips

There are several steps pet owners can take to help prevent their indoor dogs from contracting leptospirosis.

Vaccination is the best preventative measure. There are vaccines available that protect against the most common Leptospira serovars that cause the disease. Annual vaccination is recommended for dogs at risk.

Controlling rodents and wildlife around the home is important to limit exposure. Any areas where rodents or wildlife may urinate should be cleaned and disinfected regularly.

When taking dogs outside for walks, avoid areas that may be contaminated with urine from infected animals. Stay on sidewalks and out of standing water or wet grass.

Bathing and grooming dogs regularly can help remove any bacteria on their coat before they have a chance to be ingested.

Using dog boots during walks can provide a barrier against organisms entering through the paw pads. Promptly clean and sanitize paws after walks.

Cleaning any dog toys or belongings that have been taken outside can help remove contamination.

Avoiding dog parks and other high dog traffic areas can reduce exposure risk, as they may have a higher concentration of bacteria from infected urine.

Being diligent about picking up dog waste, especially in shared outdoor spaces, can help reduce environmental contamination.


While we often think of leptospirosis as an outdoor or rural disease, the truth is that indoor dogs are still at risk. Leptospirosis is spread through the urine of infected animals, which can make its way indoors through a variety of means. As this article has shown, even city dogs that never go outside can become infected through contact with a contaminated environment, other pets, or accidentally ingesting urine.

The best way to protect our dogs is through prevention. Be aware of possible transmission routes and take steps to minimize exposure. Use caution when interacting with unfamiliar dogs or environments. Promptly clean any urine accidents. Most importantly, keep your dog’s leptospirosis vaccinations current.

If your dog shows any signs of leptospirosis, don’t wait – seek veterinary care right away. Early treatment greatly improves the chances of recovery. While leptospirosis can be serious, dogs who receive quick medical care and supportive care have an excellent prognosis.

Though indoor dogs are at lower risk, leptospirosis is a threat we must take seriously. Stay vigilant, focus on prevention, and partner closely with your veterinarian to keep your dog happy and healthy.

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