Leptospirosis in Dogs

Table of Contents

Symptoms | Diagnosis | Treatment


"Canine Leptospirosis  is a bacterial disease that can cause severe illness and symptoms. Antibiotics are prescribed for the condition and continued to prevent retransmission to other dogs."


Leptospirosis is a bacteria that affects dogs and humans, as well as cats and a number of other animals. Your dog receives (or should receive) a yearly vaccine for the bacteria. However, there are eight different strains of the bacteria that affect dogs, and the vaccine only protects against two of those strains (icterohaemorrhagie and canicola). So your dog is still susceptible to other strains of the bacteria.

In North America, most cases of canine Leptospirosis occur between July and November in humid climates.

Leptospirosis is transmitted between animals through infected urine, bite wounds, and ingestion of infected tissue. People can get the disease by being bitten by an infected animal or by having infected urine come in contact with an open wound or mucous membrane. For example, if you have an open wound on your hand and are cleaning up urine from an infected dog, you are at risk for getting the bacteria. To protect yourself, wash your hands well and wear rubber gloves when cleaning up messy stuff around dogs who may be infected.

Leptospirosis - Canine Symptoms

Leptospirosis canine symptoms include a fever, shivering, lethargy, and muscle tenderness. Vomiting and diarrhea then develop. Some dogs become severely ill at that point and die. For those that survive, kidney and liver problems then usually develop. The dog may be reluctant to move due to kidney and muscle pain. The dog may have jaundice (the whites of his eyes may appear yellowish in color) from liver involvement.

Dogs that develop kidney and liver problems may begin to improve after a few weeks, or they may go into kidney failure. Dogs that appear to recover may still shed the bacteria in their urine for months or even years.

Not all infected dogs become so sick. Some dogs show very few symptoms. It depends on the strain of the bacteria. It can be very serious, though. It is very important to get your dog vaccinated so at least he is protected against some strains.


Your vet can make a diagnosis of Leptospirosis by doing a blood test or a urine culture. The blood test can tell you what strain of Leptospirosis your dog has. It will not be accurate until ten days after the infection was contracted, however. The urine culture will probably be accurate right away, but occasionally dogs do not shed the bacteria in their urine all the time so it is possible to get a false negative. If your vet does both of these tests, you should get an accurate diagnosis. If the blood test comes back negative but your dog still has all the symptoms, you can always wait a few days and then repeat the test again.


Treatment for Leptospirosis in dogs consists of antibiotics, preferably penicillin or one of its derivatives, fluid replacement, and controlling the vomiting. Kidney or liver damage must be treated accordingly.

After the initial infection is controlled, doxycycline is often given to prevent a long-term carrying state.


Canine Leptospirosis - A Persisting Challenge
F.P. Gaschen
School of Veterinary Medicine
Louisiana State University



Canine Leptospirosis
Guptill, L.