By Dial A Vet Veterinary Team
When local vets start reporting leptospirosis cases, dog owners understandably get nervous. Leptospirosis is a bacterial infection that can cause sudden kidney and liver failure in dogs, and it can also spread to people. Since 2017, clusters of cases in dogs have been reported in inner Sydney, and cases appear elsewhere in Australia after floods and wet weather. The good news is that there are clear, practical steps that greatly reduce your dog's risk.
Key takeaways
- Leptospira bacteria are shed in the urine of infected animals, especially rats, and survive in damp soil and stagnant water.
- Dogs usually catch it by drinking or wading in contaminated water, or through contact with rat urine in laneways, parks and yards.
- Vaccination is available in Australia and is the single most effective protection in risk areas.
- Early signs are vague: lethargy, vomiting, fever, not eating. Prompt testing and treatment improve survival.
- Leptospirosis is zoonotic. Use gloves and good hygiene around a sick dog.
- Related: leptospirosis in dogs, kidney failure in dogs.
How dogs catch leptospirosis
Leptospira bacteria enter the body through the mouth, nose, eyes or broken skin. Infected rats can shed bacteria in their urine for long periods without looking sick. In cities, that means risk around:
- Puddles, gutters and laneways where rats run
- Parks near restaurant bins and building sites
- Backyard water bowls left outside overnight
- Creeks, dams and flooded areas after heavy rain
Outbreaks often follow wet weather, because flooding spreads bacteria and pushes rats into new areas. Dogs that hunt or kill rats are at particular risk.
Practical steps during an outbreak
1. Check your dog's vaccination status. In Australia, a leptospirosis vaccine is available that covers the serovar most often found in local dogs. It needs an initial course followed by regular boosters. Ask your vet whether your area is considered a risk and whether your dog is up to date. Vaccinated dogs can occasionally still become infected, but disease is usually much less likely and less severe.
2. Avoid stagnant and puddled water. Carry fresh water on walks and discourage drinking from gutters, puddles, ponds and slow creeks. Keep your dog on lead in areas where you know water collects.
3. Bring water and food bowls inside at night. Rats visit bowls after dark. Wash bowls daily with hot soapy water.
4. Control rats around your home. Store pet food in sealed containers, clean up fallen fruit and bird seed, secure compost and bins, and block access under houses. Choose rodent control methods that do not put your dog at risk. Rodenticide baits can poison dogs directly, and some second-generation baits can poison dogs that eat affected rats. Discuss pet-safe options with a pest controller.
5. Stop rat hunting. Do not let your dog chase or kill rats. Use a lead in laneways and parks known for rats.
6. Be careful after floods. Keep dogs out of floodwater, mud and debris where possible, and wash and dry paws after unavoidable exposure.
Signs of leptospirosis in dogs
Signs usually appear around one to two weeks after exposure and can range from mild to severe:
- Lethargy and weakness
- Fever or shivering
- Loss of appetite, vomiting, diarrhoea
- Increased thirst and urination, or reduced urine output
- Yellow gums, eyes or skin (jaundice)
- Muscle pain, reluctance to move
- Coughing or difficult breathing in some dogs, from lung bleeding
- Small bruises on the gums or belly
When it is an emergency
See a vet the same day if your dog is lethargic and off food during a local outbreak, especially if they have been near rats or stagnant water. Go immediately to an emergency clinic if your dog has yellow gums or eyes, is breathing fast or coughing blood, is producing little or no urine, collapses, or has repeated vomiting. Leptospirosis can progress quickly, and early treatment makes a significant difference.
How vets diagnose and treat it
Vets combine history, examination, blood and urine tests, and specific tests for Leptospira. These may include PCR tests on blood and urine and antibody tests, sometimes repeated over a couple of weeks. Treatment involves antibiotics chosen by the vet, intravenous fluids, and support for the kidneys and liver. Some dogs with severe kidney injury need advanced care such as dialysis at referral hospitals. Survival is good in many dogs treated early, although the lung form carries a more guarded outlook.
Protecting people in your household
Leptospirosis can infect humans. If your dog is unwell or diagnosed:
- Wear gloves when cleaning urine, and disinfect surfaces.
- Avoid letting the dog urinate in areas where children play.
- Wash hands well after handling your dog, bowls or bedding.
- See your doctor if you develop fever, headache or muscle pain, and mention the exposure.
FAQ
Does my dog need the leptospirosis vaccine?
It depends on where you live and how your dog lives. In areas with known cases, or for dogs exposed to rats, water or farms, vets often recommend it. Ask your vet.
Can cats get leptospirosis?
Cats can be infected but rarely show severe disease. See leptospirosis in cats.
Is leptospirosis the same as Lyme disease?
No. Both are bacterial, but Lyme disease is spread by ticks and is not known to be locally acquired in Australia.
Can a dog recover fully?
Many do, especially with early treatment. Some dogs are left with reduced kidney function and need long-term monitoring.
Talk with a vet
If there are leptospirosis cases near you and you are not sure whether your dog is protected, a Dial A Vet veterinarian can talk through risk, vaccination and early warning signs. Book a Dial A Vet consult.
References
- Sykes JE, et al. Updated ACVIM consensus statement on leptospirosis in dogs. Journal of Veterinary Internal Medicine, 2023.
- Griebsch C, et al. Emerging leptospirosis in urban Sydney dogs: a case series (2017 to 2020). Australian Veterinary Journal, 2022.
- Merck Veterinary Manual. Leptospirosis in dogs.
- NSW Health. Leptospirosis fact sheet.
Disclaimer: Educational only. This page does not replace an examination or advice from your own veterinarian. If you are worried about your pet right now, contact your local vet or nearest emergency animal hospital.