Last Updated: 28/04/2026
Leptospirosis in Dogs: Signs, Risks, and Prevention
Leptospirosis is a serious bacterial disease for dogs. Learn how it spreads, the common signs to watch for, and how to keep your pup safe and protected.
Author: Dr Kes Holliday DVM
Reading Time: 4 minutes - short read
Leptospirosis might sound like a complex scientific term, but for Australian dog owners, it is a health risk that warrants attention. While cases are relatively uncommon, this bacterial infection can be severe and dangerous. Understanding how it spreads and knowing the warning signs are the best ways to ensure your furry friend stays happy, healthy, and safe from this preventable disease.
Leptospirosis in Australia
Over the last two decades, Leptospirosis in Australia has shifted from a rare, rural condition primarily associated with tropical regions and working dogs to a re-emerging urban threat. Following a notable spike in cases in Sydney beginning in 2017, the disease is now recognised as an endemic risk in major cities and coastal regions. This epidemiological change is largely attributed to increased contact with contaminated urban environments - particularly stagnant water and rodent populations - rather than the traditional livestock interactions seen in rural settings.
Recent veterinary data highlights a transition in the primary bacterial strains, with serovar Australis now frequently identified alongside the previously dominant serovar Copenhageni. Given the disease's high mortality rate and its persistent presence in urban hotspots, vaccination has become a critical preventative recommendation for dogs in at-risk areas or those with high-exposure behaviours.
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).
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 catch 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.
Protecting your dog from Leptospirosis
Vaccination
Fortunately, there is a canine vaccine available that protects against 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 disease requires minimising your dog's contact with rodents and contaminated water sources. You can achieve this by following these steps:
- Control walks: Keep your dog on a lead in high-risk areas where rodents may be present.
- Avoid water: Prevent your dog from swimming in or drinking stagnant water, such as ponds, lakes, or puddles.
- Manage the home environment: Remove food and rubbish from around your home to discourage the rats and mice that attract the disease.
Leptospirosis and human health
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.
Leptospirosis in Dogs FAQs
While the thought of a serious illness like leptospirosis can be worrying, staying informed is your best defence. By minimising exposure to high-risk areas like stagnant water and keeping up to date with vaccinations, you can drastically reduce the risk to your dog. If you are concerned about local outbreaks or your dog's vaccination status, a quick chat with your local veterinarian is the best next step to ensure your companion stays protected.
Articles recommended for you
Our vet authored guide to the benefits of feeding your dog fresh food plus tips and advice for introducing it into their regular menu.
See our guide to protecting your pet from parasites from our vet team.
Thinking of getting a fish? Check out our guide for setting up a tank and home care tips!
Looking to understand horse feeds better? This comprehensive guide covers feeding recommendations for horses of all ages and disciplines.
Does your pet suffer from anxiety? Check out our Vet-guide for treatment options to help your pet.
History
Our experts continually monitor the health and wellness space and we update our articles when new information becomes available.
Tue 28 Apr 2026
Edited by Dr Gillian Hill BVSc (Hons)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.
