Leptospirosis; The Bacteria to be Cautious About

Leptospirosis is a bacterial disease that affects humans and animals. It is caused by bacteria of the genus Leptospira. Without treatment, Leptospirosis can lead to kidney damage, meningitis (inflammation of the membrane around the brain and spinal cord), liver failure, respiratory distress, and even death”.1

There are many strains of Leptospirosis found all over the world. Dogs are a maintenance host of Leptospirosis, which means they are an animal which is “capable of acting as a natural source of leptospiral infection. . . [acting] as a continuous reservoir within an ecosystem”2. Leptospirosis in cats is rare. Dogs become infected when their mucous membranes (if they lick) or a wound or cut come into contact with urine, or urine-contaminated soil or water from an infected animal, usually wildlife or other dogs. This means that Leptospirosis can be in the stream you pass on your daily walk, wet grass at the dog park, or even a puddle in your backyard.

In dogs, clinical symptoms of Leptospirosis can include muscle pain, stiffness, weakness, trembling, lethargy, anorexia, vomiting, and jaundice, among others.  Unfortunately, these symptoms are also consistent with other diseases and therefore a blood test is required in order to confirm a diagnosis of Leptospirosis. Once diagnosed, and in the processes of diagnosing, dogs are treated with antibiotics and fluid therapy in the hopes of eliminating the bacteria and reversing organ damage. It is sometimes possible to make a full recovery if the disease is caught early, however long term damage can occur in many cases. It should not be taken lightly and if your dog is exhibiting any of these signs they should be seen by a veterinarian immediately so that diagnostics and treatment can begin.

There are also precautions that must be taken by the veterinary team and by pet owners. This is because Leptospirosis is a zoonotic disease, meaning that it is transferable between dogs and people. Protective measures mean avoiding contact with the dogs’ urine, quickly cleaning any urine with a household disinfectant, and washing your hands after handling the dogs.

Prevention is also available in the form of a vaccination. This vaccine can be administered on an annual basis at your dog’s yearly health check appointment and protects against four of the most common canine strains of Leptospirosis. Though an optional vaccine, it is highly recommended to all dogs due to the widespread outreach of the disease and the poor prognosis that often comes with its diagnosis.

If you have any additional questions about Leptospirosis or how to protect against it, call the North Hill Animal Hospital and one of our team members would be happy to answer any of your questions.


  1. https://www.cdc.gov/leptospirosis/
  2. https://pubmed.ncbi.nlm.nih.gov/6836184/
  3. https://www.merckvetmanual.com/mvm/generalized_conditions/leptospirosis/leptospirosis_in_dogs.html

Written by:  Bonnie Kemp