If your family includes a dog, “Lepto” may be a familiar word. You may remember your veterinarian talking about it, suggesting a vaccine to help protect Fido from this disease. Or you may have heard on the news that there’s a “Lepto” outbreak in Boston now.
“Lepto” is the nickname for leptospirosis, a bacterial infection that spreads in the urine of infected mammals. Exposure to infected urine, either by direct contact or indirectly through contaminated soil or water, can make your dog sick.
Leptospira bacteria survive in the environment for long periods. They like warm, wet summers with warm, wet autumns. The conditions are right this fall for leptospirosis to be a problem in our neighborhoods.
Domestic animals such as dogs, cattle, and horses are susceptible to leptospirosis. Wildlife, including mice, raccoons, and skunks, are also susceptible and can bring the disease to your backyard while you sleep at night. Your dog may be exposed directly to urine from these animals, or indirectly as the bacteria leach into soil, puddles of water, or nearby lakes.
Leptospira bacteria enter the body through several routes. The nose, mouth, and eyes are lined with soft mucous membranes that are susceptible to Leptospira penetration. These bacteria also find their way through cuts and abrasions. Fido can become infected by innocently sniffing an area where an infected animal has urinated, or wading in water that has been contaminated by the urine of wildlife or dogs. The opportunities for exposure are endless.
Once exposed, dogs may become sick within a few days. Sometimes, however, the incubation period can be a month or longer.
The signs of leptospirosis can vary. Some dogs are asymptomatic while others become very sick. Affected dogs typically present in kidney failure. However, some dogs show only liver failure, while others have double-organ involvement. The pet may be lethargic and vomiting, or have conjunctivitis.
In mild cases, the only symptom may be increased thirst or increased urination. Owners may simply report that Fido is having accidents in the house. They may think their dog is developing housetraining issues, or is becoming incontinent, when in fact Fido has a leptospirosis infection.
Your veterinarian may discuss testing for leptospirosis. Unfortunately, there is no perfect test for this infection. Blood tests can look for antibodies to Leptospira bacteria. Antibodies are how your dog’s immune system says, “Hey, I’ve seen these bacteria!” Antibodies can take a few weeks to develop, though, so this test may need to be repeated. This is called a paired titer, and rising levels are diagnostic. Another test, called the PCR, looks for DNA from the Leptospira bacteria in blood and urine. Positive tests are proof of infection, but false negatives can be frustrating to interpret.
Dogs with leptospirosis are treated with antibiotics for several weeks. Some initially require hospitalization because their condition is life-threatening. Once home, it is important for pet owners to follow the medication instructions carefully. Untreated or improperly treated dogs become carriers, shedding the bacteria in their urine for months or longer. This exposes other mammals in their neighborhoods. Dogs, wildlife, and human family members are at risk.
Fortunately, a good vaccine is available to protect Fido. There are many strains of leptospirosis that affect dogs. The vaccine protects against the common strains, with potential cross-protection to the others.
Dog owners should discuss this vaccine with their veterinarian. Leptospirosis was once considered to be a disease primarily of roaming dogs in rural areas. However, household dogs, and those that walk with leashes on trails, can be exposed to this nasty infection. Rodents and wildlife are in every neighborhood. The current outbreak in Boston is a prime example.
Although cats are rarely affected, humans are not so lucky. Leptospirosis is a zoonotic disease.
People get leptospirosis from dogs or other animals, or from exposure to contaminated swimming or drinking water. Swimming or kayaking in urine-contaminated water is the most common source of leptospirosis in people, although handling sick animals is a risk, too. Illness typically occurs within a couple of weeks of exposure to the bacteria. In people, leptospirosis can feel like the flu, with fever, chills, muscle aches, and stomach pain. About 10 percent progress to severe disease with liver failure, kidney failure, or meningitis. Dozens of cases are reported in the United States every year.
Leptospira bacteria thrive in warm water, which is why warm, wet seasons like we are currently experiencing set the stage for outbreaks.