What Is Leptospirosis?
Leptospirosis is a potentially life-threatening bacterial disease caused by spiral-shaped bacteria called Leptospira. Several different serovars — or strains — of this bacterium can infect dogs, with Leptospira icterohaemorrhagiae, L. canicola, L. grippotyphosa, and L. australis among the most clinically significant in Europe. The disease affects the kidneys, liver, and other vital organs, and in severe cases it can be fatal without prompt treatment.
What makes leptospirosis particularly concerning is that it is a zoonotic disease — meaning it can spread from animals to humans. For this reason, understanding how to protect your dog also means protecting your family.
How Dogs Contract Leptospirosis
The primary route of transmission is through contact with water or soil contaminated by the urine of infected animals — most commonly rodents such as rats and mice, but also hedgehogs, foxes, and livestock. Dogs that swim in rivers, lakes, or puddles, or that sniff around areas frequented by wildlife, are at greatest risk.
- Contact with contaminated stagnant water, rivers, or flooded ground
- Direct contact with urine from infected animals
- Bites from infected rodents
- Ingestion of infected animal carcasses
The bacteria enter the body through mucous membranes (mouth, nose, eyes) or through cuts and abrasions in the skin. This means dogs that spend time outdoors — especially in rural, agricultural, or flood-prone areas — face the highest exposure risk.
Where in Europe Is Leptospirosis Most Common?
Leptospirosis is found throughout Europe, but prevalence is higher in certain regions. Central and Eastern Europe — including Hungary, the Czech Republic, Poland, and the Baltic states — report significant numbers of cases, particularly following heavy rainfall and flooding events. Germany, the Netherlands, France, and the UK also see regular cases, often peaking in late summer and autumn when warm conditions favour bacterial survival in the environment.
Flood-prone river valleys and areas with high rodent populations are considered hotspots. Climate change and more frequent extreme weather events are increasing the risk across previously lower-risk northern regions.
Symptoms to Watch For
The clinical signs of leptospirosis can vary considerably depending on the serovars involved and the dog's immune status. Some dogs show very mild signs, while others deteriorate rapidly.
- Sudden high fever and lethargy
- Severe muscle pain and reluctance to move
- Vomiting, diarrhoea, and loss of appetite
- Increased thirst and urination (early kidney involvement)
- Jaundice — yellowing of the skin, gums, and whites of the eyes (liver involvement)
- Blood in urine or faeces
- Difficulty breathing in severe cases
Kidney failure and liver failure are the most serious complications. If you notice any combination of these signs — particularly after your dog has been near water — contact your vet immediately. Time is critical with leptospirosis.
Diagnosis and Treatment
Veterinarians diagnose leptospirosis using blood tests and urine analysis. Elevated kidney and liver markers are common findings. Specific tests such as the Microscopic Agglutination Test (MAT) or PCR testing can confirm the presence of Leptospira bacteria, though results may take time and treatment is often started based on clinical suspicion alone.
Treatment typically involves a course of antibiotics — doxycycline or amoxicillin are the most commonly used — combined with supportive care such as intravenous fluids to support kidney function, anti-nausea medication, and liver-supportive therapy. Hospitalisation is often required for moderate to severe cases. With prompt treatment, many dogs recover fully, though some may sustain lasting kidney damage.
ESCCAP Vaccination Guidelines
The European Scientific Counsel Companion Animal Parasites (ESCCAP) and the European Advisory Board on Cat and Dog Vaccines (WSAVA-affiliated) both strongly recommend vaccination against leptospirosis for dogs throughout Europe. Current guidelines favour the use of L4 vaccines, which provide protection against four serovars — including L. grippotyphosa and L. australis — compared to the older two-serovar (L2) vaccines.
- Primary course: two injections given 4 weeks apart
- Annual boosters are required to maintain protective immunity
- Vaccination is recommended even for dogs in urban areas due to rat exposure
- Dogs in high-risk areas (countryside, near water, agricultural settings) should be considered a priority
Discuss vaccination timing and schedules with your vet, particularly if your dog travels to flood-prone areas or participates in outdoor activities such as swimming or hiking.
Zoonotic Risk: Protecting Your Family
Leptospirosis is a notifiable zoonosis in many EU member states. Humans can be infected through the same routes as dogs — contact with contaminated water or soil — but can also potentially be exposed by handling the urine of an infected dog. Symptoms in humans range from mild flu-like illness to Weil's disease, a severe form causing liver and kidney failure.
If your dog is diagnosed with leptospirosis, wear gloves when cleaning up urine, wash hands thoroughly, and inform your GP if you develop a fever in the weeks following exposure. Vulnerable individuals — pregnant women, the elderly, and the immunocompromised — should take extra precautions.
Everyday Prevention Tips
Vaccination is the most effective preventive measure, but it works best alongside sensible management practices.
- Avoid letting your dog drink from or swim in stagnant ponds, puddles, or slow-moving rivers — especially after rainfall
- Keep rodent populations under control around your home and garden
- Do not leave dog food or water bowls outside where wildlife can access them
- Rinse your dog off after swimming in natural water sources
- Keep your dog's annual leptospirosis vaccine up to date
High-quality nutrition and a strong immune system also help your dog fight infection. If you are looking for premium dog foods or immune-supporting supplements, Zooplus stocks a wide range of options suitable for dogs of all ages and breeds.
Leptospirosis is a preventable disease. With regular vaccination, sensible precautions around water, and awareness of the symptoms, you can significantly reduce the risk to your dog — and to your family.