Leptospirosis in Dogs: Risks, Signs and Vaccination

By Tailwisp Editorial TeamUpdated October 17, 20263 min read

Leptospirosis is a serious infection that dog owners in many regions should know about.

What it is

Leptospirosis is caused by spiral bacteria called Leptospira that are shed in the urine of infected animals such as rats, raccoons, skunks, opossums and livestock. The bacteria survive in warm, wet environments.

How dogs get infected

• Drinking or swimming in contaminated water, such as puddles, ponds or slow streams
• Contact with contaminated soil or mud
• Contact with infected urine through cuts or mucous membranes
• Contact with wildlife or rodents

Risk is not limited to rural areas. Urban dogs can be exposed through rats and puddles.

Signs

• Fever and lethargy
• Vomiting and loss of appetite
• Increased thirst and urination
• Muscle pain and stiffness
• Jaundice (yellow gums, skin or eyes)
• Bleeding problems in severe cases
• Breathing difficulty if lungs are affected

Signs can progress quickly to kidney and liver failure. See kidney disease in dogs and liver disease in dogs.

Diagnosis

Vets use blood and urine tests, including PCR and antibody testing. Bloodwork often shows kidney and liver changes.

Treatment

• Antibiotics, typically doxycycline or penicillin-type drugs
• Intravenous fluids and hospital care
• Anti-nausea medication and supportive care
• Dialysis in severe kidney failure at specialist centers

Many dogs recover with prompt treatment, though some have lasting kidney damage.

Protecting your family

Leptospirosis can infect people. If your dog has it, avoid contact with urine, wear gloves when cleaning, wash hands and disinfect surfaces. Talk to your doctor if household members have flu-like illness.

Vaccination

Leptospirosis vaccines are considered non-core in some regions and recommended for dogs at risk, such as those who swim, hike, hunt or live where wildlife is common. Vaccines do not cover every strain, and boosters are usually annual. Discuss risks and benefits with your vet. See dog core vs non-core vaccines.

Prevention

1. Vaccinate if your vet advises.
2. Avoid stagnant water and puddles.
3. Control rodents around the home.
4. Provide fresh water on walks.
5. Wash paws and hands after outdoor trips.

Questions to ask your vet

Ask about local leptospirosis risk, which vaccine strains are included and whether your dog's lifestyle calls for vaccination. Ask what vaccine reactions to watch for and how often to boost.

Common mistakes

• Assuming only farm dogs are at risk
• Letting dogs drink from puddles
• Missing early signs
• Skipping boosters

Troubleshooting

• My dog is vomiting and drinking a lot: see a vet urgently.
• My dog has yellow gums: seek emergency care.
• A family member is ill: tell your doctor your dog has been exposed.

A simple plan

1. Assess your dog's risk.
2. Vaccinate if recommended.
3. Avoid contaminated water.
4. Act quickly on symptoms.

Real-life examples

A hunting dog recovers after early treatment. A city terrier is infected after drinking from a puddle and needs hospital care. A family takes precautions while their dog is treated. Prevention helps all.

Staying informed

Local outbreaks occur, so ask your vet about current risk.

Cleaning up and caring for an infected dog

Wear gloves when handling urine or bedding, disinfect floors and surfaces with diluted bleach, and keep your dog's bathing and toileting areas separate from children and other pets until treatment is well under way. Wash your hands carefully after every contact, and ask your doctor about your own risk.

Who should consider the vaccine

Dogs that swim, hike near streams, visit farms or live where rats and wildlife are common are often advised to be vaccinated. Even city dogs can be at risk from puddles and rodent urine. Ask your vet whether the vaccine matches the strains found locally.

The takeaway

Leptospirosis is serious but preventable. Vaccinate if at risk and avoid contaminated water.

This article is general educational information, not veterinary advice. Every dog is different. If your dog is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.