08/15/2026
💥Let’s Talk Vaccines💥
Leptospirosis!
🔴What is leptospirosis?
An infectious disease caused by a type of bacteria called Leptospira. The disease causes severe damage to the kidney, liver, and other organs, and may be fatal in severe cases. Bacteria are passed in the urine of infected animals and can survive in the environment for long periods in warm, stagnant water or moist soil. Dogs can get the infection from other animals, including skunks, raccoons, opossums, rats, wolves, and other dogs.
Cats can become infected through eating rodents, and may develop disease (Leptospirosis), but it is considered rare.
🔴How common is leptospirosis?
Leptospirosis is uncommon in areas where dogs are routinely vaccinated. However, disease outbreaks are still seen occasionally because vaccines protect against only the four most prevalent strains of Leptospira. Leptospirosis was once more common in rural, wooded areas, but it is now commonly found in urban settings.
🔴How are dogs infected?
Leptospira bacteria are carried mainly by rats and other rodents but can be carried by almost any mammal, including people. Infected or recovered carrier dogs may act as a source of the infection. Leptospira bacteria is shed in the urine of infected animals that then contaminates soil or water. In wet conditions, the bacteria reproduce, resulting in higher numbers of infective organisms. Infection most commonly occurs when contaminated water or soil contacts an animal’s mucus membranes (i.e., gums) or damaged or diseased skin.
🔴 What are the signs of leptospirosis?
Many Leptospira infections go undetected, but other cases can be life-threatening.
The most common clinical signs associated with leptospirosis are those caused by acute (sudden) kidney injury and liver dysfunction, although the bacteria can also affect other organs and functions, such as the lungs, and may cause uncontrolled bleeding, which can lead to many different clinical signs. Common signs of leptospirosis include reduced or no appetite, lethargy, and high fever.
Signs of acute kidney injury include:
vomiting, diarrhea
increased drinking, increased urination
abdominal pain
absence of urination
Signs of liver dysfunction include:
vomiting, diarrhea
icterus or jaundice (yellowing of the gums and the whites of the eyes or skin)
Signs of other affected systems:
abnormal thickening/hardening of the skin (calcinosis cutis)
abortion
bloody urine, f***s, vomit, or sneezing
coughing blood
edema causing swelling of the limbs
elevated/increased/rapid breathing
fluid around the lungs (pleural effusion) or in the abdomen (ascites)
pain, stiffness, or reluctance to move
redness and/or discomfort (squinting) in the eyes
small hemorrhages or bruises in the mouth, on the skin, or in the whites of the eyes
🔴 How is leptospirosis diagnosed?
Diagnosis starts with a thorough discussion of your dog’s clinical signs and a physical examination. Based on this investigation, additional diagnostics often include a complete blood count (CBC), biochemistry profile and urinalysis, chest radiographs (X-rays), abdominal ultrasound, and coagulation testing (tests to determine how well blood clots).
Based on the results of these tests, your veterinarian may recommend specific testing for leptospirosis, which includes running a combination of tests: a DNA-PCR test that looks for genetic material from the Leptospira bacteria in the blood or urine, and two separate microscopic agglutination tests (MATs), run two weeks apart, that test for the presence of antibodies formed against leptospirosis. Each of these tests has unique benefits and disadvantages.
🔴 What is the treatment?
Antibiotics such as penicillin, ampicillin, and amoxicillin are reasonably effective against the acute stages of leptospirosis if they are started early. These antibiotics treat the early stages of infection, making the dog feel better, although most affected dogs require intensive care in the veterinary hospital.
Other supportive treatments may be needed based on your dog’s clinical signs, including hospitalization and intravenous fluids, oxygen therapy, plasma transfusion, and hemodialysis. Your veterinarian may recommend referral to a facility that specializes in critical care.
An extended course of antibiotics, typically doxycycline, is then prescribed in the recovery period to ensure that all the Leptospira bacteria are cleared and the dog does not become a chronic carrier. Follow-up may include serial blood and urine monitoring to ensure parameters are improving in response to treatment. Your veterinarian will let you know when and how often this should occur.
🔴 How can leptospirosis be prevented?
The leptospirosis vaccine is recommended as a routine vaccination for all dogs. Your veterinarian will consider the risks and options for your pet. Annual re-vaccination is needed to maintain the best immunity. The four-serovar vaccine is currently the only vaccine recommended by experts. Modern vaccines are highly effective and safe. Recent studies of vaccine adverse events show no difference in probability of vaccine reaction from leptospirosis vaccination than from distemper-parvovirus or rabies vaccination. Talk to your veterinarian about any concerns you have.
Humans can get Leptospirosis too!
Check out this link to the Government of Canada page on Leptospirosis
https://www.canada.ca/en/public-health/services/diseases/leptospirosis.html
