Leptospirosis in Dogs - An Infection by Leptospira Bacteria

Puppies may be more seriously affected by leptospirosis than adults because they have immature immune systems.
Puppies may be more seriously affected by leptospirosis than adults because they have immature immune systems. | Source

What is Leptospirosis?

Leptospirosis is a disease that affects dogs, other animals and humans. In dogs, the symptoms of the disease range from nonexistent to life-threatening. The problem is caused by an infection with a bacterium known as Leptospira. This bacterium is found around the world and is absent only in polar regions and extreme environments such as Saharan Africa.

Dogs may develop leptospirosis when they come into contact with the urine of infected animals. This encounter is most likely to happen in the stagnant water found in puddles, ponds, bogs and waterlogged soil. If urine is present in the water, Leptospira may enter a dog’s body when the pet drinks or moves through the water. The bacterium is able to penetrate the mucous membranes in the body. It can also enter the body through skin wounds.

A mucous membrane lines the passages and cavities in the body and has important functions. Unfortunately, Leptospira is able to move through the membrane.

Dog owners should be careful about the type of water that their dog enters. Stagnant water may transmit leptospirosis.
Dog owners should be careful about the type of water that their dog enters. Stagnant water may transmit leptospirosis. | Source

The Leptospira Bacterium

The biological classification of the genus Leptospira is complex and changes as new analysis is done. There are multiple species in the genus, which all look the same when viewed under a microscope. The pathogenic (disease-causing) members of the genus are often grouped together as Leptospira interrogans.

Leptospira interrogans is a one-celled bacterium with a long, spiral body. Like its relatives, it belongs to a group of corkscrew-shaped bacteria known as spirochaetes. One or both ends of Leptospira interrogans are hooked and resemble a question mark. This feature gives the bacterium its species name. The bacterium can move, which it does at high speed, rotating and flexing as it travels. It's an interesting creature, despite the problems that it can cause.

Leptospira interrogans contains multiple serovars. A serovar has slightly different molecules on its surface compared to the other serovars in its species. The goal of a leptospirosis vaccine is to protect dogs from the serovars that are most likely to infect them. It can be very effective in doing this. It doesn't give protection against every serovar that could make a dog sick, however. If the serovars in an area change, a different vaccine may be needed.

Leptospira interrogans as viewed under a scanning electron microscope; the bacteria have been trapped on a filter
Leptospira interrogans as viewed under a scanning electron microscope; the bacteria have been trapped on a filter | Source

Causes of Canine Leptospirosis

Leptospira interrogans can infect most mammals, including humans, some domestic animals and many wild ones. Not all of the animals get sick from the infection, however. Some carry the bacteria in their body but don't develop symptoms. Rodents are considered to be the most common transmitter of the disease.

Still water is most likely to contain Leptospira. The water in muddy areas, puddles, drainage ditches, ponds and shallow lakes is potentially dangerous. Wild or domestic animals may deposit urine containing bacteria into the water, or the urine may drain into the water from the surrounding area. In urban areas, garbage soaked with rat urine can transmit the bacteria. Even a damp patch of garden or soil can contain Leptospira if an infected animal urinates there.

The Leptospira bacterium enters a dog's body when water containing infected urine contacts the mucous membranes lining the mouth, the nose, the eyes or the anus. Contaminated soil and food can also transmit the bacterium. The bacteria may also enter a dog through a skin wound, even if this is only an abrasion.

The bacteria that cause leptospirosis can live for a long time at the surface of fresh water. Once they get into a dog's body they enter the bloodstream and travel through the body. Their main targets are the kidneys and the liver, but they affect other parts of the body as well.

Leptospira bacteria (the black, thread-like structures in the central area) in a stained sample of kidney tissue
Leptospira bacteria (the black, thread-like structures in the central area) in a stained sample of kidney tissue | Source

Symptoms of Infection

Some dogs with leptospirosis exhibit no symptoms and are said to have a subclinical infection. Some develop a chronic infection. Other dogs exhibit mild symptoms that disappear on their own. Still others experience major problems that require immediate medical attention. If symptoms develop, they generally appear after an incubation period of around four to twelve days.

The symptoms listed below can be caused by other diseases besides leptospirosis. As always, a pet owner should pay attention to their dog's physical condition and behaviour. A vet should be consulted if the pet has serious symptoms of illness, multiple symptoms or mild ones that don't go away.

A Veterinarian Discusses Leptospirosis in Dogs

Possible Symptoms of Canine Leptospirosis

Possible problems in dogs who become sick from a Leptospira infection are listed below. A particular dog is unlikely to have all of the symptoms. The problems that do develop and their severity depend on the serovar of the bacterium, the way in which the dog's immune system reacts to the bacterium and the prior health of the dog.

Possible symptoms of the infection include the following.

  • a fever
  • loss of appetite
  • vomiting
  • diarrhea
  • dehydration
  • thirst
  • Increased urination
  • muscle tenderness
  • joint pain
  • reluctance to move (due to muscle, joint or kidney pain)
  • depression and lethargy
  • shivering

In some cases, a dog may exhibit other symptoms, such as the following.

  • blood in the urine, stool, saliva and vomit
  • nosebleeds
  • tiny red spots on the gums or skin
  • a yellow tinge to the whites of the eyes and the skin (jaundice)
  • fluid accumulation in the legs, abdomen or chest
  • difficulty in breathing

Leptospirosis treatment should be started as soon as possible in order to return an animal to health and happiness.
Leptospirosis treatment should be started as soon as possible in order to return an animal to health and happiness. | Source

Some Common Treatments

A diagnosis of leptospirosis is generally confirmed by a variety of blood tests. Sometimes a urine test is performed as well. Treatment often includes the administration of antibiotics and, if necessary, intravenous or subcutaneous fluids. Intravenous fluids are inserted into a vein; subcutaneous fluids are inserted under the skin. Additional medications may be given to the sick dog, such as one that controls vomiting.

It's important to begin treatment for leptospirosis as soon as possible in order to increase the chance of a happy outcome. Antibiotic treatment is often effective and dogs frequently recover from the illness. Serious damage to the kidneys or liver makes successful treatment more challenging, however. Unfortunately, fatalities do occur, despite medical treatment. The disease always needs to be taken seriously.

Shallow lakes may sometimes infect dogs with Leptospira.
Shallow lakes may sometimes infect dogs with Leptospira. | Source

In North America, leptospirosis is most common in summer and fall. These are the times of year when it is especially important to be vigilant with respect to dog safety.

Preventing Leptospirosis in Dogs

Leptospira lives in moist areas and is most abundant in the warmer times of the year. Preventative measures can reduce the chance of a dog becoming infected by the bacterium.

  • Don't allow dogs to drink stagnant water such as the water in puddles and ponds. Stop them from entering these areas as well.
  • Stop dogs from entering drainage ditches.
  • If there are notices by lakes advising people of bacterial contamination, don't let dogs enter the lake. If one type of bacterium can survive and multiply there, it's possible that others can too.
  • Clear gardens of items that may attract wild animals, such as fallen fruit and garbage.
  • Remove or enclose piles of wood and thin out dense shrubbery that may attract rats and mice.
  • Improve the drainage in areas of a garden that are continually damp.
  • Don't leave water sitting in children's wading or paddling pools for long periods of time.
  • Try to keep your dog's immune system strong by giving him or her good food and adequate exercise.
  • Investigate the use of a vaccine as a preventative measure.

Some dogs love to retrieve balls or other items, but it's important that the items aren't thrown into stagnant water.
Some dogs love to retrieve balls or other items, but it's important that the items aren't thrown into stagnant water. | Source

Vaccines and Vaccination

The leptospirosis vaccine isn't considered to be a "core" vaccine - that is, one that is routinely given to all dogs. However, many vets recommend that dogs in high risk situations receive a vaccination against leptospirosis. These dogs include those who live on farms or in rural areas, those who are taken on hunting or camping trips, those who swim in lakes or have access to ponds and drainage ditches and those who live in areas frequented by wildlife. Some vets say that even dogs who stay in cities should be vaccinated due to the possibilty of infection by urban wildlife.

Early versions of the leptospirosis vaccine caused many unpleasant reactions in dogs, but the latest versions produce fewer side effects. The vaccine needs to be given on an annual basis or even more frequently in order to provide continuous protection.

Vaccination is sometimes a controversial topic. Anyone wondering whether a leptospirosis vaccination is advisable for their dog should talk to their vet. It would be good to know which serovars of Leptospira are common in the area, what serovar protection is provided by the vaccine and what the potential side effects of the vaccination are.

The Leptospirosis Vaccination

If you have a dog, is he or she vaccinated against leptospirosis?

See results without voting
Think about how safe a body of water is before you let your dog enter it.
Think about how safe a body of water is before you let your dog enter it. | Source

A Zoonotic Disease

Preventing and treating leptospirosis in dogs is important, not only for a dog's sake but also for the sake of humans. Leptospirosis is a zoonotic disease - one that can be transmitted from animals to humans.

In North America, It's possible for a person to catch leptospirosis from a dog or another animal, but this is more likely to happen to people exposed to many infected animals than to a pet owner. Some examples of people at higher risk of developing leptospirosis are veterinarians, farmers and sewage workers. The chance of a pet owner catching the infection from their dog is low, although it isn't zero. The risk is serious enough that people should take precautions (described below) as they care for their dog.

Leptospira bacteria that have collected on a polycarbonate filter (colourized photo)
Leptospira bacteria that have collected on a polycarbonate filter (colourized photo) | Source

Human Leptospirosis

In September 2015, a report about human leptospirosis was published. (The report is referenced at the end of this article.) It confirmed the fact that in North America the disease is a relatively minor problem for the population as a whole, although maybe not for a person who develops the disease. The estimated annual incidence of death from leptospirosis ranges from an extremely low number in the colder latitudes of North America to a low number in the warmer latitudes.

Unfortunately, this low death rate is not the case for people living in tropical areas. In fact, researchers believe that leptospirosis in some tropical countries is often misdiagnosed as other diseases and is actually becoming a serious problem. In these countries, the disease is most common in urban areas with inadequate sanitation and becomes more abundant after heavy rainfall and flooding.

All of my dogs have enjoyed entering water, so I've always had to be careful about where I let them swim. Here they are sleeping after a day of swimming and hiking.
All of my dogs have enjoyed entering water, so I've always had to be careful about where I let them swim. Here they are sleeping after a day of swimming and hiking. | Source

How Can I Prevent my Dog From Transmitting Leptospirosis to Humans?

While you are treating your dog for leptospirosis there are things that you can do to reduce the chance that you, your family or other people will catch the disease. These are good techniques to use at any time. Dogs may not show any sign that they are infected by Leptospira, yet they may release bacteria in their urine for many months after the initial infection.

  • Clean up your dog's urine with an antibacterial solution, such as a disinfectant or a mixture of bleach and water. A mixture of one part bleach to ten parts water is often suggested.
  • Wear gloves if you're working in an area that may be contaminated by animal urine.
  • Don't let your dog urinate in or near still or slow-moving water.
  • Don't allow your dog to investigate or urinate in vegetable gardens.
  • Stop your dog from entering children's play areas, including playgrounds, sandboxes and wading pools.
  • Wash your hands frequently.

With the proper precautions and treatment, people can be protected from a Leptospira infection and a sick pet can very often recover and enjoy life again.

References and Further Reading

Leptospirosis in Dogs from the Merck Veterinary Manual

Leptospirosis in Humans from the CDC (Centers for Disease Control and Prevention)

Increase in the Global Incidence of Human Leptospirosis

© 2013 Linda Crampton

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Comments 26 comments

Just Ask Susan profile image

Just Ask Susan 3 years ago from Ontario, Canada

I've never heard of Leptospirosis before and glad that I came by to read your hub. Thank you for making me aware of this. I'll be sharing your article all over the place as I know so many people with dogs.


AliciaC profile image

AliciaC 3 years ago from British Columbia, Canada Author

Thank you very much for the comment and the share, Susan. I appreciate your visit. It is important that dog owners are aware of this disease. I don't stop my dog from entering water because he loves it so much and swimming is great exercise for him, but I am careful about what types of water I let him enter.


L.L. Woodard profile image

L.L. Woodard 3 years ago from Oklahoma City

Thanks for sharing this information. You've done a great job of explaining the illness and the issues surrounding it. It's an illness I had never heard of before, so as a pet owner I appreciate the heads-up.

Great hub; voted up and Shared.


AliciaC profile image

AliciaC 3 years ago from British Columbia, Canada Author

Thank you, L.L. Woodard. I appreciate your comment, the vote and the share! I expect that more people will become aware of the disease if the cases of canine leptospirosis continue to increase.


bdegiulio profile image

bdegiulio 3 years ago from Massachusetts

Hi Alicia. I had never heard of Leptospirosis before. You explained this very well and hopefully it helps other dog owners to be aware of the potential for contacting this disease. Fortunately our little Shih Tzu does not like the water so hopefully this is something that we will never have to deal with. Great job. Love the photos of your dogs, they're beautiful. VU, sharing etc..


mperrottet profile image

mperrottet 3 years ago from Pennsauken, NJ

Because we camp so frequently, our vet gives my Old English Sheepdog the vaccine for this disease. I wasn't aware that it was only good for six months, however. Lots of good information in this hub - voted up, useful, and I'm sharing.


AliciaC profile image

AliciaC 3 years ago from British Columbia, Canada Author

Hi, Bill. The fact that your Shih Tzu doesn't like water is a big help in the prevention of leptospirosis! Thank you very much for the vote and the share.


AliciaC profile image

AliciaC 3 years ago from British Columbia, Canada Author

Hi, mperrottet. Thanks for the visit, the votes and the share! Leptospirosis is uncommon in winter if the weather is cold, so a once a year vaccine works for many dogs.


drbj profile image

drbj 3 years ago from south Florida

After reading all this info, Alicia, about leptospirosis,

I am now convinced I possess a full-blown psychosis.

Very thorough examination of the disease, m'dear. Voted up!


AliciaC profile image

AliciaC 3 years ago from British Columbia, Canada Author

Thank you for the visit and the vote, drbj. Thanks for the poem too!


Just Ask Susan profile image

Just Ask Susan 3 years ago from Ontario, Canada

Alicia, I had to stop by again to let you know that I'd pinned your hub yesterday after reading it and I've gotten quite a few re-pins from it. I am sure your hub is going to make many people aware of leptospirosis.


AliciaC profile image

AliciaC 3 years ago from British Columbia, Canada Author

Thank you so much, Susan. I appreciate the pin. I will be very happy if more people become aware of this disease and protect their dogs in some way!


kashmir56 profile image

kashmir56 3 years ago from Massachusetts

Hi my friend, very interesting and useful information for all dog owners to read. Well done !

Vote up and more !!! Sharing !


AliciaC profile image

AliciaC 3 years ago from British Columbia, Canada Author

Thank you very much for the comment, the votes and the share, Tom!


ImKarn23 profile image

ImKarn23 3 years ago

Very interesting and informative!

i adore dogs - and i see you've got a soft spot for black labs - which is what my now-13-year-old-soul-puppy is..

Well..half black lab/half doberman..

At her age, i'm not overly concerned about this, as we've had to cease our regular visits to lakes and parks - walking isn't fun for her anymore..sadly..

on the other hand - she's Amazing! sometimes she even jumps up on the bed - which is purdy damn HIGH!

lol..up and sharing on!


AliciaC profile image

AliciaC 3 years ago from British Columbia, Canada Author

Hi, ImKarn23. All the black lab photos in this hub are of Misha, my dog. I'm sorry that your dog doesn't find walking fun any more, but hopefully she'll continue to enjoy life for a long time! Thank you very much for the comment and the share.


Vickiw 3 years ago

Hi AliciaC, very thorough and informative Hub. Gosh, that would really increase awareness of this nasty disease, and hopefully save the health and lives of many dogs too. Great work!


unknown spy profile image

unknown spy 3 years ago from Neverland - where children never grow up.

hi alicia. thank you so much for this very informative hub. very useful.


AliciaC profile image

AliciaC 3 years ago from British Columbia, Canada Author

Thank you very much, Vicki. I appreciate your comment. I hope that more pet owners do become aware of leptospirosis. It can be a nasty disease, as you say.


AliciaC profile image

AliciaC 3 years ago from British Columbia, Canada Author

Thanks for the visit and the comment, unknown spy!


teaches12345 profile image

teaches12345 3 years ago

Great share on how to keep dogs from getting this disease. This is the first I have heard of it, but I can see how it could be easily gotten from drinking contaminated water sources.


AliciaC profile image

AliciaC 3 years ago from British Columbia, Canada Author

Thanks for the visit and the comment, Dianna. It is important that dogs avoid contaminated water and that we are aware of potential problems that our pets could face.


Peggy W profile image

Peggy W 3 years ago from Houston, Texas

Hi Alicia,

At the current time our dog Skippy, a Pomeranian who was my mother's dog prior to her death...could care less about playing in water...even at the dog park. We have no standing water in our backyard, so are probably fairly safe regarding contracting this disease. Our very first dog Kelly, an Irish Setter, loved the water! He actually did play in ditches and other areas of water. We lucked out apparently as he stayed healthy. But this is good information to know. Up votes and will share so that others who love their pets can help protect them.


AliciaC profile image

AliciaC 3 years ago from British Columbia, Canada Author

Thank you very much for the votes and the share, Peggy! I'm glad that your past and your present dogs have been healthy. Since all my dogs have loved water, I would be shocked if I got a dog who wasn't interested in it!


sgbrown profile image

sgbrown 3 years ago from Southern Oklahoma

Living in the country, it would be easy for my dogs to come in contact with this bacterium. My dogs are able to roam around in about 40 acres. I will have to watch them carefully and look for the symptoms. I appreciate you sharing this information! Voted up and useful! :)


AliciaC profile image

AliciaC 3 years ago from British Columbia, Canada Author

Thanks for the comment and the votes, sgbrown. How wonderful to have forty acres for your dogs to explore! They must love roaming around.

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