NEW YORK — Veterinarians are urging dog owners in flood-affected areas to vaccinate their pets against leptospirosis, a bacterial infection spread through water contaminated by the urine of infected wildlife — a risk that rises sharply after flooding events.
Leptospira bacteria thrive in warm, stagnant floodwater and can survive for weeks in moist soil. Dogs that wade through or drink floodwater are at significant risk of infection, which can cause kidney failure, liver damage, and death if not treated promptly.
The disease is zoonotic — meaning it can be transmitted from infected dogs to humans — making prompt diagnosis and treatment a public health priority as well as a veterinary one. The CDC reports approximately 100 to 200 human leptospirosis cases annually in the United States, with higher rates following major flooding events.
Veterinarians recommend that all dogs in flood-prone areas receive the leptospirosis vaccine, which is not included in standard core vaccine protocols and must be specifically requested. The vaccine does not provide complete protection against all Leptospira serovars but significantly reduces the risk of severe disease.
Dog owners should prevent their pets from drinking or swimming in floodwater, avoid areas with standing water after a storm, and seek veterinary care immediately if their dog shows signs of illness — including lethargy, vomiting, fever, or reduced urination — following potential exposure.
