Leptospirosis is a bacterial disease that can be transmitted to dogs and humans.
The most common way dogs get leptospirosis is through water contaminated with urine, particularly stagnant or slow-moving water like puddles, ponds or lakes. Another source is from contact with urine-contaminated soil, bedding or food.
Many different animals can spread leptospirosis through their urine, primarily rodents and small mammals like rats and raccoons, and even some livestock. Leptospira enters the body through ingestion, broken skin or mucous membranes (eyes, nose or mouth).