• Blog >
  • Leptospirosis in Dogs
RSS Feed

Leptospirosis in Dogs

With warmer weather and longer days, summer is a great time of year to enjoy the outdoors with our four-legged friends! However, it is also a time when they are more likely to be exposed to certain diseases. Leptospirosis is one of these.

Leptospirosis is a disease caused by infection with Leptospira bacteria. It is called “Lepto” for short and has been a silent killer in our dog population since it was discovered in the early 20thcentury.

This disease is not “re-emerging” or “growing” or “new”. It is a significant cause of dog illness and death each and every year and should be treated as such.

There are many strains of Lepto and they can be found worldwide in soil and water. Leptospirosis is a zoonotic disease, which means it can be spread from animals to people.

Risk factors for Leptospirosis
Dogs are most commonly affected. Leptospirosis in cats is rare and appears to be mild although very little is known about the disease in this species.

We used to think most exposures happened in the working dog or farm dog population only. However, the area with the highest prevalence of Lepto in the US is downtown Manhattan where instead of deer and wildlife, the high rodent population spreads Lepto to unsuspecting apartment dwelling lapdogs.

Since Lepto is most commonly spread through contact with the urine of wildlife, rodents and unvaccinated dogs, any dog walking on footpaths (or wildlife trails) should be considered at-risk.
0350504001565886171.jpgOther common risk factors for Leptospirosis in dogs include exposure to, or drinking from, rivers, lakes or streams; roaming on rural properties (because of exposure to potentially infected wildlife, farm animals, or water sources) and contact with other, unvaccinated dogs (think, our local disease reservoirs – Dog Parks!).

Speaking of dog parks…In January 2018 a Fremont, CA dog park was temporarily shut down over fears of it being the source of Lepto infection in 4 dogs that contracted the disease.

Dogs can become infected and develop Lepto if their mucous membranes (or skin with any wound, such as a cut or scrape) come into contact with infected urine, urine-contaminated soil, water, food or bedding; through a bite from an infected animal; by eating infected tissues or carcasses; and rarely, through breeding. It can also be passed through the placenta from the mother dog to the puppies.

Diagnosis of Leptospirosis
The signs of Lepto in dogs vary. Some infected dogs do not show any signs of illness, some have a mild and transient illness and recover spontaneously, while others develop severe illness and death.

Signs of may include fever, shivering, muscle tenderness, reluctance to move, increased thirst, changes in the frequency or amount of urination, dehydration, vomiting, diarrhea, loss of appetite, lethargy, jaundice (yellowing of the skin and mucous membranes), or painful inflammation within the eyes. The disease can cause kidney failure with or without liver failure. Breathing problems, bleeding disorders, and fluid accumulation are also possible.
Our veterinarians may suspect Lepto based on vaccination history, lifestyle, signs shown by the dog, but many of these signs can also be seen with other diseases. In addition to a physical examination, our veterinarians may recommend a number of other tests such as blood tests, urine tests, radiographs (x-rays), or an ultrasound examination.

Treatment and prevention
Supportive care, IV fluids, and antibiotic therapy are keys to successful treatment of Lepto. Antibiotics prevent urinary shedding within 24hrs and transmission of the organism significantly decreases, as does the risk of human transfer. When treated early and aggressively, the chances for recovery are good but there is still a risk of permanent residual kidney or liver damage.

Currently available vaccines effectively prevent Lepto and protect dogs for at least 12 months. Annual vaccination is recommended for at-risk dogs. Reducing your dog’s exposure to possible sources of the Leptospira bacteria can also reduce its chances of infection.

Regardless of if your dog has Lepto or not, good hygiene practices are always recommended to protect you and your family from diseases your 4-footed-friend can share with you:

· Don’t French-kiss your dog, even if it is a French bulldog, Bichon or Papillion
· Avoid contact with your dog’s urine;
· If your dog urinates in your home, quickly clean the area with a household disinfectant and wear gloves to avoid skin contact with the urine;
· Encourage your dog to urinate away from standing water or areas where people or other animals will have access;
· Wash your hands after handling your pet.

The Research
A 2014 study from the University of California Davis (Hennebelle et al, Risk factors associated with leptospirosis in dogs from northern California: 2001-2010, Vector-Borne and Zoonotic Diseases, 2014) looked at 67 dogs with lepto and 271 non-lepto controls and provided some good, local, information.

· Dogs with Lepto can be pretty sick and treatment can be pretty expensive. On average, affected dogs were hospitalized for 11 days at a cost of $5459 (USD).
· 13% of affected dogs died.
· The main serovar was Pomona.
· There were regional differences even in California, with more cases from the central or south coast, Sierra Nevada foothills, San Francisco bay area or north coast compared to the distribution of control dogs.
· Other risk factors included being 5-10 years of age or over 10 years of age or being hound breeds.

Leptospirosis is a vaccine-preventable disease. Today’s vaccines prevent against multiple Lepto strains (including Pomona) are safe and provide solid protection for 12 months. Our Ultra vaccine line uses half the volume of other formulations to provide a more comfortable experience for your pet.

Due to recent outbreaks and the risk of people becoming infected from their pets, we recommend that MOST dogs be vaccinated against Leptospirosis.
While no vaccine is 100%, this is a cost-effective “insurance policy” against a very nasty and expensive disease.

If you have any further questions or concerns about Leptospirosis, please contact us and we would be happy to discuss it with you.

“Treatment without prevention is simply unsustainable” – Bill Gates

Your First Visit is FREE

Sign up now

No form settings found. Please configure it.

Office Hours

Our Regular Schedule


7:30 am

5:30 pm


7:30 am

5:30 pm


7:30 am

5:30 pm


7:30 am

5:30 pm


7:30 am

5:30 pm


9:00 am

1:00 pm





Find us on the map

Featured Articles

Read about interesting topics

Newsletter Signup

Sign up for more articles