Leptospirosis in Dogs: Causes, Symptoms, Treatment, and Prevention - PetHelpful - By fellow animal lovers and experts
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Leptospirosis in Dogs: Causes, Symptoms, Treatment, and Prevention

Linda Crampton is a biology teacher, writer, and long-time pet owner. She currently has dogs, cats, and birds in her family.

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.

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.

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.

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.

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

Leptospira interrogans contains multiple serovars. Each has slightly different molecules on its surface (or antigens) compared to the other serovars in the species. The goal of a leptospirosis vaccine is to protect dogs from the bacteria 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 ones in an area change, a different vaccine may be needed.

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

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

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. It's possible for one dog to transmit the infection to another one.

The 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. In addition, the bacteria may 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 inside a dog, 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. The bacteria may cause renal failure and acute liver disease.

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

The Infection: Subclinical to Potentially Deadly

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 a Leptospira Infection

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. In addition, any symptoms that do develop may indicate the presence of a different disorder. A veterinarian's diagnosis is required.

If a dog has leptospirosis, the problems that develop and their severity will likely be influenced by the serovar of the bacterium, the way in which the dog's immune system reacts to the bacterium, and the prior health of the pet.

Symptoms of the infection may 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 additional 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.

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 treating a pet 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 attention. The disease always needs to be taken seriously.

Shallow lakes may sometimes infect dogs with Leptospira.

Shallow lakes may sometimes infect dogs with Leptospira.

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 you see 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.

Vaccines and Vaccination

In many areas, the leptospirosis vaccine isn't considered to be a "core" vaccine—that is, one that is routinely given to all dogs. Vets often recommend that dogs in high risk situations receive a vaccination against leptospirosis, however. These animals 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 possibility 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

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.

The incidence of canine leptospirosis appears to be increasing in North America. For example, an outbreak began in Arizona in February, 2016. More cases than normal are still being observed in the area.

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. This is more likely to happen to people exposed to many infected animals than to a pet owner, however. 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)

Human Leptospirosis

In North America, human leptospirosis 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.

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. Follow the dilution instructions for the product carefully. Also check the safety of the product for pets.
  • 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 pet 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

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

Questions & Answers

Question: Once a dog is treated for leptospirosis, how long are they still contagious?

Answer: This is a question that you should ask your dog's veterinarian. I have read that the length of time varies considerably. A vet will likely want to examine a pet recovering from the disease periodically and may well want to monitor the dog for a while after he or she has recovered. During the monitoring period, the vet will probably check to see whether the dog is still shedding bacteria. Until a vet confirms that no more bacteria are being shed, safety precautions should be followed in relation to preventing the spread of the bacteria from the infected dog to another dog or a person.

© 2013 Linda Crampton

Comments

Linda Crampton (author) from British Columbia, Canada on March 02, 2013:

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

Sheila Brown from Southern Oklahoma on March 02, 2013:

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! :)

Linda Crampton (author) from British Columbia, Canada on March 01, 2013:

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!

Peggy Woods from Houston, Texas on March 01, 2013:

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.

Linda Crampton (author) from British Columbia, Canada on February 25, 2013:

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.

Dianna Mendez on February 25, 2013:

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.

Linda Crampton (author) from British Columbia, Canada on February 19, 2013:

Thanks for the visit and the comment, unknown spy!

Linda Crampton (author) from British Columbia, Canada on February 19, 2013:

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.

Life Under Construction from Neverland on February 19, 2013:

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

Vickiw on February 19, 2013:

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!

Linda Crampton (author) from British Columbia, Canada on February 18, 2013:

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.

Karen Silverman on February 18, 2013:

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!

Linda Crampton (author) from British Columbia, Canada on February 18, 2013:

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

Thomas Silvia from Massachusetts on February 18, 2013:

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

Vote up and more !!! Sharing !

Linda Crampton (author) from British Columbia, Canada on February 17, 2013:

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!

Susan Zutautas from Ontario, Canada on February 17, 2013:

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.

Linda Crampton (author) from British Columbia, Canada on February 17, 2013:

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

drbj and sherry from south Florida on February 17, 2013:

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!

Linda Crampton (author) from British Columbia, Canada on February 17, 2013:

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.

Linda Crampton (author) from British Columbia, Canada on February 17, 2013:

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.

Margaret Perrottet from San Antonio, FL on February 17, 2013:

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.

Bill De Giulio from Massachusetts on February 17, 2013:

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..

Linda Crampton (author) from British Columbia, Canada on February 16, 2013:

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.

L.L. Woodard from Oklahoma City on February 16, 2013:

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.

Linda Crampton (author) from British Columbia, Canada on February 16, 2013:

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.

Susan Zutautas from Ontario, Canada on February 16, 2013:

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.