The canine vaccination that protects dogs who spend a lot of time in ponds and lakes is the Leptospirosis vaccine. Leptospirosis is a bacterial infection caused by Leptospira bacteria, which are often found in water bodies like ponds, lakes, and rivers, particularly where there is wildlife or livestock nearby.

Dogs can contract leptospirosis by coming into contact with contaminated water, soil, or urine from infected animals. The vaccine helps protect against this potentially serious infection, which can lead to kidney and liver damage in dogs and can also be transmitted to humans (zoonotic disease).