How Long Is Leptospirosis Contagious After Treatment for Canines?

If your dog comes down with leptospirosis, a bacterial infection, he could be fighting for his life. Prompt treatment with antibiotics can save him, but even after recovery he still sheds the bacteria in his urine. It could take a month or two, sometimes longer, before he's no longer contagious. It's not just other dogs who are at risk. Leptospirosis is a zoonotic disease, meaning you can catch it from your canine.

Caused by spirochetes, leptospirosis spreads throughout the body via the bloodstream of an infected animal. Some infected dogs remain asymptomatic, although they can shed the bacteria. Other dogs have mild symptoms, while certain dogs become seriously ill and die. Symptoms include fever, constant drinking and urinating, muscle pain, weakness, diarrhea and vomiting, appetite loss, eye inflammation, shivering and signs of jaundice in the mucous membranes. Urine and feces might contain blood. Fluid might accumulate in the legs or abdomen. Without prompt treatment, seriously ill dogs can suffer liver or kidney damage. To avoid leptospirosis infection, don't let your dog swim in streams, ponds or lakes, or drink from these water sources. The most common source of infection is contact with the urine of an infected animal, often found in such wet areas.

Your vet diagnoses leptospirosis by conducting tests on the blood and urine, along with ultrasounds or X-rays. Once diagnosed, mildly affected dogs usually receive long-term antibiotic therapy, specifically doxycycline or penicillin. More seriously affected animals might require hospitalization and intravenous fluid therapy. Even after your dog recovers, he still might be shedding the bacteria in his urine. You'll have to take him to the vet for regular urine testing until there's no sign of the bacteria. While most dogs are "clean" within a couple of months after treatment, in some animals it can take a year or more.

While your dog is on antibiotic therapy or until his urine specimens are clean, limit his "constitutional" walks to specific, isolated areas unlikely to be frequented by other canines or children. These areas should not be near any body of water, including swimming pools. If your dog has an accident in the house, wear gloves when cleaning up urine, feces or vomit and disinfect the area. Wash your hands carefully after petting or handling your dog.

If your dog is at risk for leptospirosis, ask your vet about vaccinating him against the disease. Canines at particular risk include hunting dogs or those living near water or marshy areas. After an initial series of shots, your dog should have an annual booster.