Dog in the woods
Black and White headshot of IndeVets Employee Courtney
Words by:
Courtney Zinna, DVM — Associate IndeVet

As a small animal veterinarian practicing in the state of New Jersey, I find that many people are unaware of the dangers of Leptospirosis. This bacterial infection is spread by the common local wildlife, such as deer, rats, and raccoons, which many of us have right in our backyard. Even our local livestock can become infected with this pathogen and spread it to our canine companions and us! Once infected with Leptospira, the secondary effects of this bacteria on your pet’s kidneys and liver can result in extreme illness and even death.

In this article, we will discuss Leptospirosis, outline common symptoms, and how to prevent your dog from contracting this potentially fatal disease.


What is Leptospirosis?

Leptospirosis is a disease caused by a group of bacteria called Leptospira that can survive in many environments and can be found throughout the United States. The bacteria that cause Leptospirosis are commonly transmitted in the urine of infected wildlife species into areas of stagnant water such as puddles and lakes, but they can also survive in soil.

Your canine companion can be exposed to Leptospirosis by drinking this stagnant water, licking the soil, or coming in direct contact with an area where the bacteria was excreted in contaminated urine. Leptospira can survive for extended periods in the environment and especially in areas with warmer weather and increased rainfall.


What are the common signs of Leptospirosis?

Once infected with Leptospirosis, the symptoms you may notice in your pet include the following:

  • Diminished appetite or refusal to eat
  • Vomiting
  • Diarrhea
  • Extreme tiredness or malaise
  • Jaundice (Yellowing of the skin caused by liver damage)

These symptoms can be mild at first and are common for pets feeling unwell for other reasons. As such, Leptospirosis can be challenging to diagnose early. While some dogs may never show any clinical signs and clear the infection on their own, many dogs infected with Leptospira will eventually become extremely ill. These pets can require immediate and aggressive emergency care due to acute kidney injury and liver damage.


What to do if your dog is exhibiting symptoms of Leptospirosis

Based on clinical history, location, and physical exam findings, your veterinarian will assess your pet and determine if Leptospirosis could be the cause of your pet’s clinical signs. If your veterinarian suspects Leptospirosis, they will recommend testing. This is essential to consider, especially if you live in an area where these bacteria are more common, as Leptospira are very contagious between animals. Leptospirosis is also zoonotic, meaning it can be spread from infected animals to humans. Suppose your veterinarian diagnoses your pet with Leptospirosis with special testing (like PCR and antibody-based tests). In that case, they will recommend treatment that consists of antibiotics to fight the infection and supportive care like hospitalization and IV fluid therapy to limit secondary damage to the liver and kidneys. Many cases diagnosed early will have a good prognosis for complete recovery. Still, some pets are left with lifelong kidney damage, and many patients diagnosed late will not survive.


How to prevent Leptospirosis

Thankfully, a vaccine can be given to your dog by your veterinary team to protect them from this infection. The vaccine will protect against four of the most common strains of bacteria that cause Leptospirosis and should be given to your pet yearly after an initial series if you live in an area where Leptospirosis is a concern or if your dog’s lifestyle puts it at higher-than-average risk – for example, if your pet likes to drink from puddles, swim in lakes, or chase local wildlife. If you are unsure of your pet’s vaccine status or would like to discuss your pet’s risk for Leptospirosis, discuss with your veterinarian ASAP!