What Is The Leptospirosis Vaccine for Dogs?

If you've just acquired a puppy you might be wondering about the diseases your dog should be vaccinated against. One of the diseases people want to learn about is leptospirosis and to understand how the leptospirosis vaccine works for dogs.

In this guide, we'll explain everything you need to know about leptospirosis vaccine (sometimes referred to as the lepto vaccine) for dogs is, what it does and why your dog needs it.

About the leptospirosis vaccine for dogs

The leptospirosis vaccine prevents the disease caused by the bacteria leptospira. This bacteria can be spread to dogs through the urine and is acquired through contaminated water and food. It is common in dogs, but rarely seen in cats.

The vaccine is important for dogs especially on farms, in kennels, in shelters and in urban areas which are prone to floods.

What's in the leptospirosis vaccine?

The leptospirosis vaccine for dogs contains a highly diluted version of the virus. The vaccine isn't considered dangerous to people or other animals, but some dog owners have reported an adverse reaction in their dogs.

In 2013, veterinarians in Orange County, California warned pet owners not to allow dogs to go swimming during rainy months because the leptospirosis vaccine can make animals more susceptible to the disease.

Death from the disease was reported in the state in 2011 and in 2014.

Dogs should be kept away from bodies of water such as swimming pools, ponds, and other water sources during rainy months.

What Is The Leptospirosis Vaccine for Dogs?

Can humans contract leptospirosis?

Yes. Humans are mammals. As such, leptospirosis can infect you and even your children. Humans (and even some dogs) may be asymptomatic carriers if infected with leptospirosis but the disease can be devastating.

What happens if your dog is not given the leptospirosis vaccine? (symptoms of leptospirosis)

When dogs aren't vaccinated against leptospirosis and they contract the disease, they can experience the following symptoms:

  • fever, anorexia
  • vomiting
  • abdominal pain
  • liver or kidney problems

If you are worried your dog may have leptospirosis or even if your dog is displaying just one of the leptospirosis symptoms above, contact your vet straight away.

These symptoms of leptospirosis can last from a few days to several weeks.

Vaccinating against leptospirosis is essential. Leptospirosis can be a deadly, fatal disease for dogs, particularly puppies or elderly / frail dogs.

leptospirosis vaccine for dogs

What does the leptospirosis vaccine for dogs do?

Leptospirosis is a bacterial infection that spreads through the urine of infected animals. It can be spread from dogs to humans but humans are often asymptomatic carriers of the bacteria, which can spread to other dogs or livestock when they come into contact with infected urine.

To better prevent leptospirosis in dogs, most veterinarians recommend following a schedule of leptospirosis vaccines, with the first shot administered around 6-8 weeks old, followed by a boost given 1-2 weeks later.

Many boarding kennels and dog care establishments will not accept dogs that have not been given the leptospirosis vaccine.

Potential side effects of the leptospirosis vaccine for dogs

The most frequently observed side effects of the leptospirosis vaccine administered to dogs include:

  • mild or moderate redness in the eye or eyelids
  • some itching
  • redness or crusting around the eye or eyelids
  • joint pain
  • muscle stiffness.

This is consistent with findings from previous studies of the vaccine's effectiveness in protecting animals from the disease.

Important: The side effects of the leptospirosis vaccine are considerably less dangerous than the disease itself. Side effects are not common. On a balance of risk, the risk of your dog contracting leptospirosis is of greater risk to their health and life than the leptospirosis vaccine.

A note about the danger of asympomatic carriers of leptospirosis

According to this study:

"Asymptomatic dogs can be potential hosts of leptospirosis. However, the extension of this phenomenon in endemic areas has not yet been clearly defined. This study is aimed at evaluating the role of asymptomatic dogs as carriers of Leptospira in an endemic area of Brazil. A total of 131 male dogs without apparent leptospirosis symptoms were included in the study based on clinical and hematologic exams."

This presents a danger, because asymptomatic dogs display no signs of the illness caused by leptospirosis but they can pass the disease on to other dogs who may become seriously ill or even die of the disease.

Leptospirosis can be treated with antibiotics if caught early, but can be fatal if left untreated.

What does leptospirosis look like?

No one knows exactly why both dogs and humans develop scarring as a result of leptospirosis infection.

But researchers believe that the developing blood vessels inside the eyes are most susceptible to leptospirosis-related damage during this stage of the disease. Leptospirosis also can damage blood vessels in the skin and, sometimes, there is scarring that doesn't resolve.


Scientists know that post-vaccination leptospirosis isn't always a death sentence. However, dogs that are very young or very old, or that have other health problems may be more likely to die from the disease.

Even for healthy animals, recovery takes weeks or months, depending on the severity of the disease so vaccination is an obvious choice for most dog owners.

If you have any further questions about the leptospirosis vaccine for dogs, please feel free to comment below and we will be happy to put your query to a qualified veterinarian.

As ever, if your dog shows signs of illness always speak to your vet as soon as you can.

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