Leptospirosis in Dogs: An Emerging Concern for Florida Pet Owners

As a veterinarian practicing in Central Florida, I’ve witnessed many changes in veterinary medicine in my decade of experience. One of the trends I am closely monitoring is an increase in canine leptospirosis cases. This bacterial disease, once considered relatively uncommon in our region, has become an important health threat that every dog owner should understand.

Leptospirosis is a bacterial infection which is shed in the urine of infected animals, particularly wildlife such as raccoons, opossums, and rodents. Dogs become infected through contact with contaminated water, soil, or surfaces. The bacteria enter through mucous membranes (such as gums) or broken skin, making any dog who goes outside potentially vulnerable.

One of the biggest concerns is that leptospirosis can spread from animals to humans. Infected dogs shed bacteria in their urine that can remain on the fur of our pets, potentially exposing family members.

Florida’s climate provides ideal conditions for Leptospira bacteria to thrive. Frequent rainfall, lakes, and ponds create standing water that can harbor the bacteria for months. Combined with our abundant wildlife population and increased urbanization bringing pets and wildlife into closer contact, we’re seeing a perfect storm for disease transmission.

Leptospirosis can range from mild to life-threatening cases. Some dogs can even be carriers, showing no signs at all but continuing to spread the disease through their urine. Early symptoms often include fever, lethargy, loss of appetite, and muscle pain. As the disease progresses, it can cause severe kidney and liver damage, leading to organ failure. Some dogs develop bleeding disorders or respiratory distress. Without prompt treatment, leptospirosis can be fatal, and even with aggressive therapy, some dogs suffer permanent organ damage.

Cats can get leptospirosis as well, but they seem to be much more resistant to life-threatening symptoms. However, it may play a role in long-term kidney disease in cats.

What makes this disease particularly insidious is its ability to mimic other conditions, sometimes delaying diagnosis until significant organ damage has already occurred.

Fortunately, we have an effective tool: vaccination. The newest leptospirosis vaccine now protects against the four most common strains affecting dogs in North America.

I strongly recommend leptospirosis vaccination for virtually all dogs in Florida. While rural pets are at higher risk, leptospirosis most commonly occurs in urban dogs whose only exposure is to pests in a city. Unfortunately, there is no approved vaccine for cats, but keeping your cat indoors reduces their risk of encountering the bacteria.

Given Florida’s environmental conditions and the severity of leptospirosis, vaccination represents our best defense. Combined with common-sense precautions such as avoiding standing water and controlling wildlife access to your property, vaccination can significantly reduce your dog’s risk.

I encourage every dog owner in Florida to discuss leptospirosis vaccination with their veterinarian. This preventable disease is becoming increasingly common in our state, and protecting your dog also protects your family.

Dr. Caroline Hecker is the medical director at Lake Emma Animal Hospital in Lake Mary. She graduated from the University of Edinburgh school of veterinary studies in Scotland. She lives in Lake Mary with her husband, two kids, and numerous animals.