Last Updated: 12/03/2026
Everything You Need To Know About Leptospirosis In Dogs
Author: Dr Kes Holliday DVM
Reading Time: 3 minutes - short read
Leptospirosis is an uncommon but serious bacterial disease that can infect dogs and other mammals. Transmitted through contact with rodents, leptospirosis causes severe illness in affected dogs.
We've summarised the key points about leptospirosis and how you can keep your dog safe from this deadly disease.
Leptospirosis in Australia
Leptospirosis is an uncommon disease in Australia. It is found mainly in the coastal tropical areas in Queensland north of Mackay and in the Northern Territory. However, a different strain of leptospirosis is linked to recent outbreaks in Sydney and Melbourne.
Throughout 2019 - 2020, approximately 11 cases of leptospirosis were reported in dogs from Sydney suburbs including Surry Hills, Darlinghurst , Redfern and Glebe. Tragically, all dogs died or were euthanised following infection with the disease. A handful of cases were also reported in Melbourne in the Ringwood region during this period.
There has been a recent case of a dog infected in Sydney's northern beaches in June 2021. Despite specialist veterinary treatment, the dog sadly passed away. The dog had not travelled from the Narrabeen/Elanora area - which means the leptospirosis infection was acquired locally.
How is Leptospirosis Transmitted?
Leptospirosis is a bacteria that is spread in the urine of infected animals, and can survive in water or soil for months. The bacteria enters the body by being swallowed, crossing damaged skin or even by sniffing.
Infection can occur when a dog drinks from a water source that a rodent has urinated in (such as a puddle or drain). The recent mouse plague in NSW's central west is implicated in the outbreak in Sydney.
What are the signs of Leptospirosis?
The first signs of illness in dogs with leptospirosis can be non-specific and may include vomiting, diarrhoea, weakness, fever and refusal to eat. If left untreated, the disease progresses to kidney failure, liver failure and even death.
If you live in a high-risk area and your dog is unwell, contact your veterinarian for advice.
Can cats become infected with Leptospirosis?
All mammal species can be infected with leptospirosis bacteria (including humans!) However, in a suburban setting, cats are less likely to be exposed to the disease. To date, there have been no recorded clinical cases of leptospirosis in cats in Australia.
Leptospirosis in humans
Leptospirosis is a zoonotic disease, which means it can be transmitted from animals to humans. Infected animals may not show clinical signs of disease but can shed the bacteria in their urine. Although transmission from pets to humans is rare, always practice good hygiene when cleaning up after pets and avoid contact with stagnant water in affected areas.
Read more about Leptospirosis in people: NSW Health Leptospirosis fact sheet.
How to keep your dog protected
Vaccination
Fortunately, there is a canine vaccine available that protects agaisnt a common strain of leptospirosis. If you live in an area where leptospirosis has been detected, vaccination is recommended. We advise speaking to your regular veterinarian to determine your dog's individual risk and vaccination requirements. There is an initial vaccine course of two vaccinations given 2 - 4 weeks apart. The vaccination must then be given every year for continued protection.
Preventing transmission
Preventing contact with rodents and contaminated water sources are also key in preventing disease. This means walking your dog on lead in high risk areas where rodents may be present. Prevent your dog from swimming in or drinking stagnant water such as ponds, lakes or puddles. Rats and mice are attracted to food and rubbish around homes - so removing these sources will also reduce risk of contact.
Further Resources
Want to know more? Check out our Discover Page for more tips on keeping your pets happy and healthy.
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History
Our experts continually monitor the health and wellness space and we update our articles when new information becomes available.
Thu Mar 12 2026
Edited by Dr Olivia Clarke BSc BVMS MANZCVS (Unusual Pets, Avian)Dr Kes Holliday DVM
Veterinarian
Dr. Kes graduated from the University of Melbourne in 2014 with a Doctor of Veterinary Medicine and has worked at small animal clinics in rural Victoria and Melbourne. Dr Kes also worked as an export veterinarian for a pet transport company, helping to move dogs and cats across the world! Her fields of interest include animal behaviour, fish and veterinary public health.
