Leptospirosis is a disease that affects dogs, as well as many other kinds of animals. The organism that causes leptospirosis is a spirochete bacteria and is found throughout the world. There are a very large number of Leptospira; about 230 of them have been identified.
In the United States, Leptospirosis is in the environment because it is carried in rats, wildlife, as well as domestic livestock. More cases are seen in late summer and fall and often after heavy rainfalls. Leptospira is known to exist in standing water, dampness, and mud. Winter conditions tend to lower the risk because Leptospira do not tolerate freezing temperatures.
Pets can become infected through contact with urine of infected animals such as raccoons, skunks, rats, feral cats, dogs, and other animals. Often, dogs contract the disease by swimming in stagnant water or drinking contaminated water in puddles.
Should Dog Owners Be Concerned About Leptospirosis?
Not all dogs that are exposed to Leptospirosis become visibly ill. In a 2007 study, 25 percent of unvaccinated healthy dogs had antibodies to Leptospirosis. This indicated to researchers that they had been previously exposed to Leptospirosis without their owners noticing a problem.
When Leptospirosis does cause disease in dogs, it tends to be most severe in unvaccinated dogs that are younger than 6 months of age. It takes about 4-12 days after exposure for a dog to start to feel ill.
Signs of illness vary, but usually include lethargy, poor appetite, fever, vomiting, increased thirst or urine production. Jaundice may also be seen. Blood tests will show changes in kidney values or liver and kidney values.
Diagnosis is made through blood and urine tests that look specifically for Leptospirosis. Antibiotics are typically used to treat Leptospirosis; not only can they treat the active infection, but also may prevent dogs from becoming carriers of the organism.
How Can Dog Owners Prevent Leptospirosis?
Prevention is best accomplished by stopping your dog’s access to contaminated water. Also, try to sanitize your dog's environment by eliminating food and garbage to reduce the attraction of rats, raccoons, or feral cats.
Leptospirosis is a zoonotic disease. In other words, it is contagious to humans. The most likely way humans contract Leptospirosis is via exposure to dog or rat urine. However, any bodily fluid, including vomit and saliva, can transmit the disease. If your dog is infected with Leptospirosis, it is very important to observe proper hygiene even after he has recovered (wearing protective gloves when cleaning up after your dog, preventing face licking, etc.)
Vaccination for leptospirosis is an option to consider if your dog is at high risk of contracting the disease. The American Animal Hospital Association considers Leptospirosis a “non-core” vaccine for dogs. That is, they do not recommend it unless there is a good chance your dog will be exposed to Leptospirosis. The efficacy of the vaccine is variable: short lasting or limited. There have been reports of reactions to the vaccine that vary from minor to severe.
Vaccination does not always prevent infection, but it tends to make the disease much milder if infection occurs. There is the potential for vaccinated dogs that do become infected to become long term carriers of Leptospirosis. Some long-term carriers have more frequent incidence of reproductive failure and stillbirths.
As with all vaccinations, you should discuss the vaccine for leptospirosis with your veterinarian. This decision will be based on you and your dog’s life style, if your community is experiencing cases of Leptospirosis, and the other pros and cons your veterinarian has experienced with the vaccine.