Yes, cats can get leptospirosis. Both domestic and wild cats are susceptible to infection with Leptospira bacteria, though they handle it very differently than dogs do. Most infected cats show few or no symptoms, which has led to the disease being significantly underrecognized in felines. A global meta-analysis found that roughly 10% of domestic cats tested positive for antibodies against Leptospira, meaning they had been exposed at some point, while about 4.6% showed evidence of active or recent infection.
Why Lepto in Cats Gets Overlooked
Leptospirosis is well known as a serious, sometimes fatal disease in dogs. In cats, the picture is dramatically different. Cats rarely develop obvious clinical signs after infection, and healthy cats appear to have some degree of natural resistance to the disease. This has led many veterinarians and pet owners to assume cats simply don’t get lepto, but the evidence says otherwise.
The confusion stems from the gap between exposure and illness. Cats get infected at meaningful rates, but most fight off the bacteria without ever looking sick. In the few confirmed clinical cases described in the veterinary literature, the main finding was kidney damage at various stages of severity, without the liver involvement that’s common in dogs. So when a cat does get sick from lepto, it looks like a kidney problem, which can easily be attributed to other, more common causes of feline kidney disease.
How Cats Get Infected
Cats pick up Leptospira the same way other animals do. The bacteria thrive in warm, moist environments and are shed in the urine of infected animals, especially rodents. A cat that hunts mice or rats has direct contact with potentially infected prey. Cats can also be exposed through contaminated standing water, soil, or contact with urine from other infected animals.
Outdoor and free-roaming cats face the highest risk. European studies have found antibody rates ranging from about 4% in parts of Spain to nearly 18% in outdoor cats in Germany. Wild feline species, including mountain lions, bobcats, and jaguars, also test positive, with a pooled seroprevalence of around 13%. The common thread is environmental exposure: the more time a cat spends outside in contact with wildlife and standing water, the greater the chance of encountering the bacteria.
What Happens When a Cat Is Infected
Most cats that encounter Leptospira develop a subclinical infection, meaning the bacteria enter their body and trigger an immune response without causing noticeable illness. These cats may carry low levels of antibodies for months after exposure. Some become chronic carriers, harboring the bacteria in their kidneys and intermittently shedding it in their urine. Experimentally infected cats have been shown to shed Leptospira in their urine for up to 10 weeks.
In rare cases, particularly when a cat has a weakened immune system, the infection can become clinically significant. One documented European case involved a young outdoor cat that was simultaneously fighting feline panleukopenia, a severe viral illness that suppresses the immune system. The confirmed clinical cases in cats have primarily involved kidney insufficiency at varying stages. Possible signs to watch for include increased thirst, changes in urination, lethargy, loss of appetite, and, less commonly, jaundice (a yellowing of the eyes or skin).
The Zoonotic Concern
The fact that cats often look perfectly healthy while carrying and shedding Leptospira is a genuine public health consideration. Leptospirosis is zoonotic, meaning it can spread from animals to people. Humans typically get infected through contact with the urine of an infected animal or with contaminated water or soil, often through cuts or mucous membranes.
Because cats rarely look sick, their role as potential carriers has historically been underestimated. Researchers now describe cats as possible reservoir hosts, animals that maintain the bacteria in circulation and can serve as a transmission source to other animals and, theoretically, to their human households. The risk is likely low for any individual cat owner, but it’s worth being aware of if your cat is an active outdoor hunter. Basic hygiene when cleaning litter boxes, like wearing gloves and washing hands thoroughly, reduces any potential exposure.
How Feline Lepto Is Diagnosed
Testing for leptospirosis in cats relies on two main approaches. The first is a blood test that looks for antibodies, which typically become detectable about 15 days after infection. This test indicates whether a cat has been exposed, but a single result can be hard to interpret. Vets usually need two blood samples taken a couple of weeks apart to see whether antibody levels are rising, which would suggest an active infection rather than old exposure.
The second approach is a DNA-based test performed on blood or urine that directly detects the presence of the bacteria. This is the preferred test for suspected acute infections. A positive result on urine means the cat is actively shedding the bacteria into the environment. For chronic carriers that shed intermittently, a single negative result doesn’t completely rule out infection.
Treatment and Outlook
When a cat does develop clinical leptospirosis, treatment follows the same general principles used in dogs: antibiotics to clear the active infection and supportive care for any kidney damage. Because clinical disease in cats is rare, treatment protocols are largely adapted from canine medicine. Most healthy cats that encounter Leptospira clear or control the infection on their own without any treatment at all.
There is currently no leptospirosis vaccine approved for cats, unlike the vaccines available for dogs. Prevention centers on reducing exposure. Keeping cats indoors eliminates most risk. For outdoor cats, limiting access to areas with standing water and reducing opportunities to hunt rodents can help, though controlling a cat’s hunting behavior is, of course, easier said than done.
Indoor vs. Outdoor Risk
For a strictly indoor cat with no exposure to wildlife or standing water, the risk of leptospirosis is essentially zero. The bacteria don’t survive long in dry indoor environments, and without contact with infected animals or contaminated water, there’s no route of transmission.
The picture shifts for cats that spend time outside, particularly those in rural areas, near farms, or in regions with large rodent populations. Warm, humid climates and areas prone to flooding carry higher environmental loads of the bacteria. If your cat roams outdoors and hunts, periodic testing may be worth discussing with your vet, especially if your cat develops unexplained kidney problems.