Leptospirosis in Dogs: Global Strains, Vaccination & Prevention

Leptospirosis is a bacterial disease that affects both humans and animals worldwide. With over 250 known strains (serovars), it poses a serious health risk, especially in regions prone to flooding and high rodent populations.

Why Leptospirosis Matters Globally

Leptospira bacteria thrive in moist environments and are spread through the urine of infected animals. Humans and dogs can contract the disease through contact with contaminated water, soil, or food. Outbreaks often follow flooding events, making climate change a key driver of risk.

Global Strains of Leptospira

Different regions face different dominant strains:

• New Zealand: Copenhageni (rats), Pomona & Hardjo (livestock)
• North America & Europe: Canicola, Grippotyphosa, Pomona, Icterohaemorrhagiae
• Tropical regions: Additional strains linked to wildlife and flooding

This diversity means vaccines vary by country. In New Zealand, dog vaccines typically protect against Copenhageni only, while in North America and Europe, vaccines often cover four strains.

Why Vaccinate Dogs Against Leptospirosis

Dogs are both victims and vectors of leptospirosis. They can suffer severe illness and may shed bacteria in their urine for months, posing a risk to humans. Vaccination is essential to protect pets and reduce transmission.

Recommended protocol:

• Primary course of two vaccines, given 2–4 weeks apart
• Annual boosters to maintain immunity

A Human Story: When Leptospirosis Strikes

In a recent NZ Herald article ( behind a paywall), a farmer shared how he mistook leptospirosis for a simple chill—until it became life-threatening. His experience underscores the importance of early diagnosis and prevention.

Global Prevention Tips

• Vaccinate pets and livestock
• Wear protective gear when handling animals or soil
• Avoid untreated water sources
• Control rodents
• Seek medical care early for flu-like symptoms after exposure

Learn More

Explore our Pet Health Products and check the AVMA website  for more resources on preventing leptospirosis.

Stay informed. Stay protected.