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Leptospirosis prognosis: Clinical characteristics and prognosis of patient with leptospirosis: A multicenter retrospective analysis in south of China

Canine leptospirosis | Cornell University College of Veterinary Medicine

Canine leptospirosis is a bacterial infection that can have serious consequences in dogs and can also affect humans. There are multiple strains of the bacteria called Leptospira that cause leptospirosis. Prevention of leptospirosis includes vaccination, which protects against the four most common strains, and avoiding common sources of contamination.


Leptospirosis can be found across the United States, though some regions may be more susceptible than others. The bacteria thrive in warm and wet environments, especially during late summer and into fall, and they can survive for weeks to months. Periods of heavy rainfall can make it easier to spread.

The most common way dogs get leptospirosis is through water contaminated with urine, particularly stagnant or slow-moving water like puddles, ponds or lakes. Another source is from contact with urine-contaminated soil, bedding or food.

Many different animals can spread leptospirosis through their urine, primarily rodents and small mammals like rats and raccoons, and even some livestock. Leptospira enters the body through ingestion, broken skin or mucous membranes (eyes, nose or mouth). The incubation period, or the time between exposure to the organism and the appearance of symptoms, is about one week.

Clinical signs

Leptospira attaches to cells that line blood vessels (endothelial cells) which can make it harder for blood to clot normally. The bacteria spreads throughout the body and affects organs, most notably the liver and kidneys. Signs can range from mild to severe, and sometimes become life-threatening.

These common signs may be seen in varying degrees of severity:

  • Fever
  • Decreased appetite
  • Vomiting
  • Diarrhea
  • Increased thirst and urination
  • Lethargy or weakness
  • Stiffness and soreness

Other signs may include dehydration, yellowing of the eyes or gums (jaundice), small bleeding under the skin (petechiae), redness to the eyes (uveitis) and more. In severe cases, rapid or difficulty breathing may be noted from bleeding into the lung (pulmonary hemorrhage).


Leptospirosis can be difficult to diagnose because the clinical signs may resemble many other diseases, or the vaccine history may be uncertain. Your veterinarian will recommend blood work and urine testing.

Based on these results, additional testing to confirm a diagnosis is needed such as a PCR test, which looks for DNA of the Leptospira organism, and testing for antibodies. Chest x-rays may be needed to check for a pulmonary hemorrhage.


Leptospirosis is treated with antibiotics, most commonly doxycycline, for at least two weeks. Hospitalization with IV fluids and management of electrolytes is often necessary initially.

Additional treatments may include medications to protect the gut, prevent nausea and pain, provide nutritional support and manage blood pressure.


Leptospirosis is responsive to antibiotics and complete recovery is possible, but some dogs that survive may be left with chronic kidney or liver disease. Some dogs may not survive if the infection has caused significant organ damage or severely affected the ability of blood to form clots.

Dogs with respiratory issues may be less likely to survive.


Leptospirosis is a zoonotic disease, which means there is the possibility for it to spread from mammals to people. Gloves should be worn if handling any urine. If there is any accidental contact, hands should be thoroughly washed.

Vaccinating your dogs will decrease the risk of human exposure, as well as protecting against infection.


Prevention is much simpler than treatment, and your veterinarian can discuss with you if it is an appropriate vaccine for your dog’s lifestyle.

  • Vaccinate dogs annually with the leptospirosis vaccine
  • Limit access to standing water
  • Prevent rodent problems
  • Avoid contact with wildlife

After the first vaccine, your dog will need a booster in 3-4 weeks. Your dog should then receive a booster once a year.

Dr. Aly Cohen and her Pomeranian Mishka. Photo provided.

Dr. Aly Cohen is an extension veterinarian for the Cornell Richard P. Riney Canine Health Center and a clinical instructor for Cornell’s Maddie’s Shelter Medicine Program. She also serves as the contract veterinarian for the Ross Park Zoo in Binghamton, New York. Dr. Cohen graduated from the Ross University School of Veterinary Medicine, and her veterinary interests include surgery and emergency medicine. She has two Pomeranians named Mishka and Java.

AKC Canine Health Foundation | An Update on Canine Leptospirosis


Author: Sharon M. Albright, DVM, CCRT

What is Leptospirosis?
Leptospirosis, often referred to as “lepto”, is a disease caused by infection with numerous different serovars of bacteria in the genus Leptospira. (Serovars are closely related microorganisms distinguished by a characteristic set of antigens. ) It is a zoonotic disease affecting humans and animals that is spread through urine-contaminated water such as stagnant puddles and ponds frequented by infected wildlife. Outbreaks of leptospirosis have been reported after natural disasters such as floods and hurricanes where large amounts of standing water serve as a source of contamination. Even the thaw of snow or heavy rains can wash contaminated animal urine into streams and other bodies of water. In humans, leptospirosis can cause many symptoms such as fever, headache, vomiting, jaundice (yellow skin and eyes), abdominal pain, diarrhea, and rash. Infected dogs can also show a variety of signs, but the most common clinical presentation involves signs secondary to liver and kidney failure such as lethargy, anorexia, vomiting, abdominal pain, and excessive thirst and urination. If caught early, the disease is treatable with antibiotics. However, the prognosis is worse for animals already presenting to the veterinarian with severe organ dysfunction.

Many unanswered questions –
Lepto has historically been considered a disease of rural environments. As the human population grows and urban cities expand, is this still accurate? Are there local hot spots where lepto occurs with more frequency? Which dogs are at greatest risk for infection or severe disease? How can we use this information to best prevent disease in dogs?

With funding from AKC Canine Health Foundation (CHF) Grant 02380-A Estimating Prevalence and Identifying Risk Factors for Canine Leptospirosis in North America, Dr. Jason Stull and his team at The Ohio State University set out to answer these questions regarding leptospirosis in North America. They examined leptospirosis test results (data provided by IDEXX Laboratories, Inc.) in the US from 2009-2016 and in Canada from 2009-2018. They also conducted a case-control study on canine leptospirosis in the Chicago area. Results were recently presented at the 2019 AKC Canine Health Foundation National Parent Club Canine Health Conference and are shared here as the latest epidemiologic data on canine leptospirosis in North America.

Leptospirosis test results in the United States –
Examining over forty thousand test results during an eight-year period in the US, the prevalence of positive test results did vary from year to year, perhaps reflecting variations in a number of dog and environmental factors, such as recent precipitation needed to create the hospitable environment in which lepto can easily spread. Positive test results were more prevalent in the Midwest and Southwest US, as previously reported in a poster presentation by Smith, A, Arruda, AG, Wittum, T, and Stull, J. 2019. Canine Leptospirosis in the United States (2009-20169): Use of PCR Testing to Unravel Complex Spatial, Temporal, Human-and Animal-Level Risk Factors. Positive test results were also more common in the fall season, although this seasonality varied in different regions of the country.

Data analysis revealed the following risk factors for canine leptospirosis:

  • Being less than 5 years old
  • Being a male
  • Living in the Midwest and Southwest United States
  • Living in an area with more rainfall and moist conditions
  • Fall season

Leptospirosis test results in Canada –
Examining 10,000 test results during a ten-year period in Canada revealed risks similar to those found in the US. One unique finding in Canada is that dogs living in an urban setting were more likely to test positive for lepto than those living in a rural setting.

Case-control study findings –
A case-control study helps determine if a potential pathogen exposure is associated with a disease outcome. Once cases and controls are identified, researchers look back in time to learn which subjects in each group had the exposure. In this study, cases were defined as dogs with clinical signs of leptospirosis and a positive diagnostic test that lived in Chicago, IL for at least four weeks before diagnosis. Controls were defined as dogs without a diagnosis or suspicion of leptospirosis also having lived in Chicago for at least four weeks. Chicago was chosen since the commercial laboratory data described above indicated it as an area with increased prevalence of leptospirosis positive test results and showed a significant outbreak in that region.

Examining the data led to some interesting results:

  • More than 25% of lepto cases were fatal.
  • Young dogs were more likely to be infected than older dogs and cases did occur in dogs six months of age or younger.
  • Small dogs (less than 14 lb) were more likely to be affected than larger dogs (33-60 lb).
  • Dogs not vaccinated for lepto were more than 20 times more likely to be affected than dogs that had completed an appropriate lepto vaccination protocol.

The high prevalence of leptospirosis in young dogs and small dogs in this study represents a change from the standard paradigm of lepto being a disease of large-breed dogs living in a rural environment. It indicates a need for further study, increased awareness of this disease among dog owners and veterinarians, and additional prevention efforts.

What does it all mean?
The goal of this research is to identify the geographic areas of greatest risk for canine leptospirosis and to determine key behaviors and practices that can be used to successfully reduce the risk of leptospirosis in dogs. Based on these results, Dr. Stull provides the following recommendations to help prevent canine leptospirosis:

  1. Know the risk factors for canine leptospirosis such as dog age, size, sex, geographical location, and season.
  2. Reduce your dog’s exposure by avoiding (when practical) slow moving water and puddles – even in an urban environment.
  3. Work with your veterinarian to determine the appropriate leptospirosis prevention strategy for your dog. If vaccination is recommended, start when the dog is young and follow recommended protocols as long as your dog is at risk.
  4. Stay educated about the latest leptospirosis research through the AKC Canine Health Foundation and your local veterinary resources.

Resources –
The following educational resources are available to help you stay informed about the risks of leptospirosis in dogs:

  • AKC Canine Health Foundation Leptospirosis Fact Sheet
  • Webinar: The Increasing Threat of Canine Leptospirosis – Keys to Diagnosis, Therapy, & Prevention (original air date April 10, 2018)
  • Poster presentations from The Ohio State University on canine leptospirosis research with funding provided by the AKC Canine Health Foundation.

There is more to learn –
The AKC Canine Health Foundation and its donors remain committed to advancing our knowledge of canine leptospirosis and other diseases. “The diversity and depth of AKC Canine Health Foundation-funded research has the capacity to alter the standard of care in veterinary medicine,” states Dr. Stull. The next phase of his leptospirosis research will examine veterinary attitudes and practices regarding this disease to inform and improve communication among dog owners and veterinarians. Together, we can ensure that all dogs live longer, healthier lives. Support CHF-funded research at akcchf.org/donate.

UPDATE: These findings have been published in BMC Veterinary Research. Read the full, peer-reviewed publication at doi.org/10.1186/s12917-019-2148-6.

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GBUZ SK Novoaleksandrovskaya RB – Prevention of leptospirosis

Prevention of leptospirosis

Leptospirosis is a natural focal zoonotic infectious disease characterized by liver damage, as well as damage to the kidneys and nervous system against the background of general intoxication. Often accompanied by hemorrhagic symptoms and jaundice. The causative agent of leptospirosis can enter the body through mucous membranes or injured skin. From infection to the first clinical manifestations of leptospirosis can take from several days to a month. In the early diagnosis of leptospirosis, the microscopic detection of leptospira in a blood preparation plays an important role; the results of bacterial culture are often retrospective.

Leptospirosis usually has a favorable prognosis, deaths are mainly associated with insufficient or untimely medical care and a weakened state of the body. Currently, mortality from leptospirosis does not exceed 1-2%. An increase in this indicator to 15-20% is possible during periods of mass epidemics.

Prevention of leptospirosis primarily means control over the incidence of farm animals, as well as limiting the reproduction of rodents (disinfestation of urban facilities, rural farms). Sanitary and hygienic measures include monitoring the state of water sources (both places of water intake for the needs of the population and public beaches), agricultural land.

Specific vaccination measures involve the administration of a killed leptospirosis vaccine to persons working with animals or to citizens who are in an epidemic focus during outbreaks of leptospirosis.
The source of infection is primarily rodents, hedgehogs, as well as farm animals (pigs, cattle), dogs. Leptospira are excreted with animal waste products, polluting water, soil, vegetables, and plants. It is impossible to catch leptospirosis from a sick person.
The disease has many mechanisms of transmission:

Alimentary – infection occurs when drinking water from open reservoirs, as well as food contaminated with the urine of a sick animal;

Contact – infection occurs when damaged skin, mucous membranes come into contact with contaminated water, soil. information_items_118

A person is at risk of getting leptospirosis when swimming in stagnant water. Water can be contaminated with urine, faeces of sick animals. Thus, Listeria is able to penetrate not only through damaged skin, but also through the mucous membrane of the mouth, nose, and also through the conjunctiva of the eyes. You can get leptospirosis even when walking barefoot on contaminated soil.

People who work on livestock farms, meat processing plants, and also carry out their work in wetlands are at high risk of the likelihood of the disease. Do not discount veterinarians, animal shelter workers, public utilities, who can become infected from sick dogs.

Human susceptibility to infection is very high . So, when bathing in a pond, a person can get sick even if there is a small area of ​​damaged skin and a small amount of bacteria in the water.

To prevent the disease, avoid swimming in low-flowing water bodies, as well as drinking water from open water bodies. It is important to prevent the appearance of rodents in places where vegetables are stored (warehouses, cellars).

Groups of people at high risk of infection (veterinarians, animal breeders, workers in meat processing plants, disinfectors) must wear protective clothing when performing work duties. In addition, these people are subject to vaccination with a killed leptospirosis vaccine, which is administered subcutaneously in 2 ml twice, with an interval of ten days. A year later, revaccination should be carried out. After a suspected infection, doxycycline may be given as emergency prophylaxis.

Leptospirosis: symptoms, diagnosis, treatment, prevention



Sergey Anatolyevich

Experience 19 years

Allergist (immunologist), Candidate of Medical Sciences, member of the Russian Association of Allergologists and Clinical Immunologists, member of the European Academy of Allergology and Clinical Immunology (EAACI).

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Leptospirosis is a disease of an infectious nature and an acute course. Its causative agent is the bacteria Leptospira, and the main points of “impact” are the muscles, central nervous system, capillaries, kidneys and liver. You may know this disease by the name of water fever.

It is distributed throughout the world, and most pathogens are found in swampy areas and very humid regions. The causative agent of leptospirosis is most often carried by rodents, pigs, horses, dogs, and also representatives of cattle. Among animals, mortality from this disease can reach 90%. It also affects a person very seriously, so most often it requires immediate hospitalization.

Infection, incubation period, stages

Usually, the infection enters the body through mucous membranes, wounds, the gastrointestinal tract and the genitourinary system – it passes from contaminated water, food, soil. The incubation period most often takes from four days to two weeks, but in some cases stretches to a month. Most cases of the disease occur at the end of summer and the beginning of autumn. At risk are agricultural workers, veterinarians.

In the first stage, leptospirosis is accompanied by high fever, chills, weakness, and nausea. The infection attacks the surfaces of cells. The second stage is characterized by the penetration of infection into the capillaries, their defeat. The liver, adrenal glands, kidneys, brain membrane, central nervous system suffer. Pain in the muscles, headaches are added to the general signs of malaise and intoxication.

At the third stage, antibodies to the pathogen appear in the blood, the main signs of the disease begin to become dull. The fourth stage is associated with the formation of an immune response to infection and recovery.

Since there are several types of pathogen, immunity is formed only for a specific one – in the future, infection with other variants of leptospira is possible.

Signs of disease

The first symptoms of the disease include a sharp increase in temperature up to 39-40 degrees, chills, headaches, weakness, redness of the eyes.

The main symptoms of leptospirosis (other than those mentioned) look like this:

  • muscle pain – most often in the calves, thighs, in the lumbar region. Sometimes the skin can hurt;
  • swollen lymph nodes, as well as some organs, such as the spleen or liver;
  • rapid weight loss;
  • problems with sleep and psychological state: insomnia, anxiety, irritability;
  • redness of the throat, usually slight;
  • cardiac arrhythmia, decreased pressure;
  • swelling in the face.

A rash with leptospirosis refers to additional signs – it does not always appear. The same goes for symptoms such as jaundice, anemia, nausea or vomiting.

Risk of disease and complications

Diagnosis of leptospirosis is extremely important in the initial stages of the disease, since it can lead to a host of serious complications, among them:

  • internal bleeding;
  • acute renal or hepatic failure;
  • heart problems;
  • pneumonia;
  • meningitis;
  • pancreatitis;
  • paralysis and paresis of various kinds;
  • toxic shock;
  • and even death.

An infected person is in dire need of medical attention.

Types of disease

There are several classifications of leptospirosis, to name a few of them. By type, the disease is distinguished with and without jaundice, and by the leading syndrome – 4 variants of the disease. There are cases when the kidneys are more affected, or the kidneys and liver at the same time, as well as the meninges. The variant with increased bleeding is also highlighted separately.

According to the severity of the disease, mild, moderate and severe degrees are distinguished. In the first case, the level of intoxication is mild, the internal organs are not affected. In moderate course, there are all signs of leptospirosis and severe intoxication, and in severe cases, internal organs are already affected.

Also, the disease can proceed without complications and with complications, give or not give relapses.


To make a diagnosis, not only visual and other signs of leptospirosis are taken into account. It is extremely important to conduct a number of studies:

  • to study the general and biochemical analysis of blood, the general analysis of urine;
  • perform PCR or RT-PCR tests, as well as diagnostics of RNHA and HCR;
  • make a coagulogram, ultrasound, lumbar puncture (if necessary).

Clinical guidelines for leptospirosis suggest differentiation (separation) of the disease from diseases that manifest themselves in a similar way. In this case, these are hepatitis of different types.


To effectively treat leptospirosis, the patient is first taken to the hospital – this is a prerequisite, since the disease can lead to deadly complications.

Further, patients are prescribed medication, which includes at least four groups of drugs, each of which is responsible for its own tasks. It is necessary to introduce a vaccine against the pathogen, remove local symptoms, remove the effects of intoxication, etc. Depending on the condition of the patient, complex procedures on special equipment can also be used, for example, support for the kidneys if they do not cope with their functions.

Additionally, a diet is provided. If we are talking about kidney damage, then this is diet No. 7, with liver damage – No. 5.


An important point is the prevention of leptospirosis, which allows you to avoid the disease or significantly reduce the risk of infection. Preventive measures include the following:

  • vaccination against leptospirosis. Vaccination is carried out from the age of seven. In adulthood, it is shown to people working in the agricultural sector, veterinary medicine;
  • careful observance of the rules of personal hygiene;
  • refusal to swim in places where it is prohibited or simply not allowed. Avoid any untested bodies of water;
  • work with animals only in compliance with personal safety measures. If possible, animals should be vaccinated with a special serum;
  • timely treatment of any damage to the skin and mucous membranes with special means.