Introduction
Leptospirosis, or “lepto,” is a serious bacterial disease that can affect both dogs and humans. It spreads through water contaminated with the urine of infected animals, often in puddles, ponds, or after heavy rains and floods.
Thanks to new research funded by the AKC Canine Health Foundation, scientists are uncovering how and where this disease is spreading, which dogs are most at risk, and how we can better protect our pets (Grant 02380-A: Estimating Prevalence and Identifying Risk Factors for Canine Leptospirosis in North America). This breakthrough offers critical insights that could help save lives and improve prevention strategies for dogs across North America.
Key Points
- Leptospirosis is more common in the Midwest and Southwest U.S., especially in the fall and in wet conditions.
- Young, male, and small-breed dogs are at higher risk.
- Urban dogs in Canada were more likely to test positive than rural dogs.
- Dogs not vaccinated for lepto were 20 times more likely to get sick.
- Over 25% of infected dogs in the Chicago study did not survive.
The Impact of Canine Leptospirosis
Leptospirosis was once thought to be a rural disease, mostly affecting large-breed dogs exposed to wildlife or farm animals. But as cities expand and climates shift, this assumption no longer holds true.
Outbreaks have been linked to urban environments and extreme weather events like floods and snowmelt, which create standing water where the bacteria thrive. Infected dogs can suffer from severe liver and kidney damage, and the disease can be fatal if not caught early. This evolving threat called for updated research to understand where and how dogs are getting sick today.
Tracing Research Advancements
Dr. Jason Stull and his team at The Ohio State University, supported by the AKC Canine Health Foundation, analyzed over 40,000 U.S. test results (2009–2016) and 10,000 Canadian results (2009–2018). They also conducted a case-control study in Chicago, a known hotspot for canine leptospirosis.
Key findings include:
- Higher prevalence in the Midwest and Southwest U.S., especially during fall. This regional trend was also highlighted in a 2019 poster presentation: Canine Leptospirosis in the United States (2009–2016): Use of PCR Testing to Unravel Complex Spatial, Temporal, Human- and Animal-Level Risk Factors.
- Dogs under 5 years old, males, and those in rainy or moist areas were more likely to test positive.
- In Canada, urban dogs were at greater risk than rural ones.
- In Chicago, small dogs (<14 lb) and unvaccinated dogs were significantly more likely to be infected.
- The disease was fatal in over 25% of confirmed cases in the Chicago study.
These findings challenge the outdated belief that only large, rural dogs are at risk and highlight the need for broader awareness and prevention.
Driving Progress Today
This research is already reshaping how veterinarians and dog owners think about leptospirosis. It emphasizes the importance of vaccination, especially for young and small-breed dogs, and encourages pet owners to avoid letting dogs drink from or play in stagnant water, even in cities.
Future research will explore how veterinarians communicate about leptospirosis and how to improve prevention strategies. The ultimate goal is to ensure all dogs, regardless of size or location, are protected from this potentially deadly disease.
UPDATE: These findings have been published in BMC Veterinary Research. Read the full, peer-reviewed publication at doi.org/10.1186/s12917-019-2148-6.
