Canine Leptospirosis

This name of this bacterial disease is often shortened to "lepto." That abbreviation may sound cute, but in reality, this disease is no playful matter for infected canines not receiving appropriate treatment. It is preventable via vaccination. As this disease can be spread to humans, having your canine companion vaccinated may help protect not only him, but also you and your family.



Lepto is caused by Leptospira interrogans—a member of the corkscrew-shaped bacteria group called spirochetes. This group is divided into subfamiles scientifically called serovars or strains. More than 200 serovars of lepto exist, with only a few causing disease in canines. However, the strains guilty of canine infection have been identified and effective vaccines are available.

Four Strains Affect Dogs

Four strains or serovars of lepto are currently known to affect dogs. These four are included in the lepto vaccination. Only one of the strains—canicola—uses dogs as its reservoir host (the animal it lives on) until it becomes a full-blown infection. The other three strains—grippotyphosa, pomona and icterohaemorrhagiae—live in a reserve status on wild animals such as deer, racoons, rats, skunks, opossum, small rodents and squirrels, and on domestic livestock such as cows and pigs.

How Infection Is Transferred

The bacterial infection is transferred to dogs via contact with infected urine. Wild animals aren't particular regarding where they urinate; the contaminated urine often ends up in water sources that dogs swim in or drink from while they are outdoors. While urine does soak into the ground, the bacteria can remain in the soil for up to six months, according to WebMD.

Symptoms Of Infection

Fever is the earliest sign a dog has a lepto infection. Loss of appetite for several days, vomiting, lethargy, depression, muscle pain and diarrhea or blood in the urine are also symptoms of a lepto infection. The whites of an infected dog's eyes can turn yellow in cases that advance in severity. This symptom, jaundice, leaves the dog susceptible to hepatitis.

Bodily Damage

Cases left untreated can lead to a disruption of the blood's normal coagulation process. Spontaneous bleeding from the mouth and rectum can occur. The canicola and gripotyphosa strains attack the kidneys; the pomona and icterohemorrhagiae strains attack the liver. Younger dogs often have liver damage when any of the four strains affecting canines are left untreated.


Canines with advanced cases should be treated and kept in a veterinary clinic to avoid spreading the disease and to be monitored during their treatment and recovery. Various antibiotics are effective in treating this disease: penicillin and streptomycin are regularly combined for initial treatment. Doxycycline—an antibiotic that decreases the bacteria's ability to make the protein it feeds off of—is also used to accelerate control of the lepto infection.


Vaccination is one of the most effective ways to prevent your canine companion from contracting lepto. Initial vaccination is administered twice over the course of a month. Annual boosters are recommended. The lepto vaccine is generally not combined with other vaccinations. It is a stand-alone shot. Prices vary, but the average is $15 per booster shot.

By Amy M. Armstrong

About the Author
Amy M. Armstrong is a former community news journalist with more than 15 years of experience writing features and covering school districts. She has received more than 40 awards for excellence in journalism and photography. She holds a Bachelor of Arts in communications from Washington State University. Armstrong grew up on a dairy farm in western Washington and wrote agricultural news while in college.