Guide: leptospirosis in dogs
Leptospirosis in Dogs: Signs, Risks and the Lepto Vaccine
Leptospirosis in dogs is a bacterial infection that damages the kidneys and liver. Dogs pick it up from water or soil soiled by the urine of infected wildlife. It can pass to people too. Early antibiotics work well, and a yearly vaccine lowers the risk.
What leptospirosis is
Leptospirosis is caused by bacteria called Leptospira. VCA Animal Hospitals explains that the disease damages the kidneys, the liver and other organs (VCA). The Merck Veterinary Manual adds that it can cause sudden kidney failure and sudden liver failure.
The bacteria live in warm, standing water and in moist soil. Therefore, cases tend to follow wet weather.
How leptospirosis in dogs spreads
According to the Centers for Disease Control and Prevention, pets are infected through direct contact with infected urine or with contaminated water, especially when they drink from slow-moving or stagnant sources such as ponds, lakes and streams (CDC).
VCA names the usual carriers: skunks, raccoons, opossums, rats and other dogs. The bacteria enter through the gums and other mucous membranes, or through broken skin.
So a small dog in a suburb is not exempt. A puddle in the yard or a damp corner where rodents pass is enough.
Signs of leptospirosis in dogs
Early signs are vague, which makes the disease easy to miss.
| Stage or organ | Signs |
|---|---|
| Early | Fever, low energy, poor appetite, sore muscles or joints |
| Kidneys | Vomiting, diarrhea, drinking and urinating more, abdominal pain |
| Liver | Vomiting, diarrhea, yellow gums or yellow whites of the eyes |
| Less common | Nosebleeds or bruising, coughing, trouble breathing |
The early signs are listed by the CDC, the kidney and liver signs by VCA, and the bleeding and breathing signs by Merck. If your dog shows several of these, and especially after time near standing water, see your vet promptly.
How it is treated
Timing matters. The CDC says an animal treated early with antibiotics may recover faster, and that early treatment helps prevent severe organ damage.
VCA notes that antibiotics such as penicillin, ampicillin and amoxicillin are reasonably effective in the early stage. Even so, most dogs need a hospital stay with intravenous fluids, followed by a longer course of doxycycline during recovery. Severe kidney cases may need dialysis.
The vaccine for leptospirosis in dogs
- What it covers. Merck says vaccines are available for four of the most common types of leptospirosis in dogs.
- Who should get it. VCA recommends the four-type vaccine for all dogs.
- How often. Both VCA and Merck say yearly boosters are needed to keep protection up.
- Its limits. The CDC points out that the vaccine does not protect against every strain.
Many owners of small dogs have heard that the lepto shot causes more reactions. However, VCA reports that recent studies of vaccine side effects show no difference in the chance of a reaction between the leptospirosis vaccine and the distemper-parvovirus or rabies vaccines.
Your veterinarian will set the timing of the first doses. Our puppy vaccine schedule shows where it usually fits.
Can people catch it?
Yes. VCA calls leptospirosis the most common infection in the world that passes from animals to people. In addition, the CDC warns that an untreated animal may keep shedding the bacteria in its urine for up to three months.
If your dog is diagnosed:
- Wear gloves when you clean up urine, and wash your hands afterward.
- Clean soiled surfaces with an antibacterial cleaner, or with one part household bleach in 10 parts water, as the CDC advises.
- Keep the dog from urinating near standing water or where children play.
- Give every dose of the antibiotics.
- Tell your own doctor if anyone at home falls ill.
How to lower the risk
- Vaccinate, and keep the yearly booster on time.
- Do not let your dog drink from puddles, ponds or slow streams.
- Carry fresh water on walks and hikes.
- Control rodents around the house, and keep trash and pet food sealed.
- Drain standing water in the yard.
A clean, indoor start helps as well. Our article on home raised vs kennel raised puppies explains how a puppy’s first environment affects its health.
Related guides
- Puppy Vaccine Schedule and Deworming: What Is Done Before Go-Home and What Comes Next
- Distemper in Puppies: Signs, Spread and the Vaccine That Prevents It
- Coccidia in Puppies: Signs, Treatment and Cleaning Up
- Puppy Vomiting: Common Causes and When to Call the Vet
- Umbilical Hernia in Puppies: Is It Serious and Does It Need Surgery?
See all our puppy guides, read about our health testing, or meet our Havapoo puppies for sale and Goldendoodle puppies for sale.
Sources
- Centers for Disease Control and Prevention. Leptospirosis in Animals. cdc.gov
- VCA Animal Hospitals. Leptospirosis in Dogs. vcahospitals.com
- Merck Veterinary Manual. Leptospirosis in Dogs. merckvetmanual.com
Sources were checked on October 7, 2026. This article is general information and does not replace advice from your veterinarian.
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