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Leptospirosis in dogs - details of the disease


Leptospirosis is a disease that the World Health Organization has included in the category of dangerous zooanthropic infections. About half of sick animals and one third of infected people die from it.

Leptospirosis in dogs more common than other pets. It leads to dysfunction of many body systems, especially blood vessels, liver, and kidneys. Even timely, active treatment does not guarantee a successful outcome.

Description and features of the disease

Many mammals can have leptospirosis and be infected. Mice and rats are especially dangerous in this regard. Once infected, they for life become the spread of this disease. A person becomes infected through food as a result of contact with sick or recently recovered dogs.

Sources of infection are leptospira pathogens. Signs of the disease appear within a few days of the appearance of leptospira in the body of a mammal. Bacteria quickly multiply and spread throughout the body, the temperature of which rises in response to infection.

After getting into the renal epithelial tubules, the division of bacterial cells is particularly intense. Red blood cells die due to infection, anemia begins. The bilirubin pigment accumulates - the disease destroys liver cells, passes into the icteric stage. An animal that does not receive drugs to fight the disease dies from renal failure.

The causative agents of leptospirosis were identified and described by Japanese biologists in 1914. Initially, they were attributed to spirochetes, a year later, in the spirochete class, an independent family of Leptospiraceae and the genus - leptospira (Leptospira) were determined for them.

Pathogenic bacteria have an elongated long body twisted into a spiral. The ends of the body often bend like the letter “C”. The length is in the range of 6-20 microns, the thickness is 0.1 microns. High mobility and microscopic dimensions contribute to the rapid settlement of the body after infection.

There are many types of leptospira bacteria. Not everyone is dangerous to animals and humans. Sometimes leptospira behave insidiously: they do not violate the health of their carriers, but when they enter the body of another animal or person, they show their pathogenic essence.

Dog diseases cause two varieties: Leptospira Icterohaemorrhagiae and Leptospira canicolau. Bacteria remain viable by getting into the environment. In ponds, puddles, in moist soil, they can exist for several months.

Most often, a dog can become infected with leptospirosis after drinking or swimming in an infected pond.

The pedigrees of the Leptospira Icterohaemorrhagiae species are mainly rodents. A dog may become infected through contact with water containing rodent urine or directly through caught mice and rats. Leptospirosis, obtained through bacteria of this species, is almost guaranteed to lead to jaundice.

Signs of Leptospirosis in a Dog develop gradually. The animal rises in temperature. The dog constantly drinks and often urinates. In her mouth, ulcers may appear on the tongue. Diarrhea with blood and vomiting begins, jaundice appears. The dog is depressed, it becomes noticeable that she is suffering from internal pain.

Leptospirosis caused by the variety Leptospira canicolau differs from the first variant in a milder course, absence or weak severity of jaundice. Most often, bacterial invasion occurs through the urine of sick or recently recovered dogs.

Sources of infection

Healthy dogs can become infected with leptospirosis by drinking water from puddles and picking food from the ground. Contact with objects in which sick animals have left saliva or urine can lead to unpleasant consequences. Bathing in lakes and ponds threatens the migration of leptospira from water to the dog's body. Veterinarians do not exclude the possibility of infection through the bites of fleas and ticks.

The infection penetrates through damaged mucous membranes, ulcers of any nature on the body or in the gastrointestinal tract. Genital tract and infection through the respiratory system are not excluded. Exist dog leptospirosis vaccinesbut they do not completely prevent the possibility of invasion.

The probability of the disease is higher in dogs with impaired immune systems, which are crowded, without observing sanitary standards. Often infected street animals, poorly fed, in contact with rodents. Dogs living in rural areas have a higher chance of getting sick than urban dogs.

Infection consists of 2 stages: bacteremic and toxic. At the first stage, leptospira enter the bloodstream, multiply and spread throughout the circulatory system, penetrate the liver, kidneys and other parenchymal organs.

The onset of the second stage is characterized by lysis (decay) of leptospira with the formation of endotoxins. The main goal of toxins is vascular epithelial cells. As a result, the integrity of the capillaries is violated. Local bleeding characteristic of leptospirosis begins.

Toxins secreted by leptospira destroy small vessels of the internal organs. Sites of necrosis appear in the kidneys, fatty degeneration begins in the liver, hemorrhages occur in the spleen. Signs of jaundice appear.

Yellowed mucous membranes of the mouth and eyes indicate infection with leptospirosis

About a week after infection, a sick dog with urine and saliva begins to spread leptospira, becoming a source of infection. The selection of pathogenic bacteria can last several weeks or several years after the complete recovery of the animal. Therefore, the dog must be isolated.

When caring for infected puppies and dogs, safety precautions must be observed: use gloves, disinfect objects, instruments where blood could get, and dog excreta. The owner of the animal must monitor their own condition. If you feel unwell, seek medical advice.

Symptoms and signs of the disease

Decreased activity, fast fatigue, decreased appetite - the first symptoms of leptospirosis in dogs. If this is followed by irrepressible thirst, rapid breathing, fever - you must consult a veterinarian.

After 2-5 days, leptospirosis manifests its specific signs: fever, diarrhea and vomiting with blood. To them is added necrosis of the mucous membranes, frequent urination, the appearance of ulcers in the jaws of the dog.

There are many signs of leptospirosis, not all of them may be present in a particular diseased individual. In some cases, the symptoms do not appear clearly. Examination by a veterinarian, laboratory tests can give an answer about the beginning of the infection process.

Leptospirosis can develop in several ways:

With the latent, latent nature of the disease, the temperature rises slightly. The dog's activity decreases, appetite worsens. After 2-3 days, the symptoms disappear. The dog looks healthy. But laboratory tests for the presence of leptospira bacteria are necessary for antibiotic therapy.

Very rarely, the disease takes a sluggish, chronic form. Its signs are a slight increase in temperature, an increase in lymph nodes in the groin and under the jaw. Urine becomes dark yellow, brown. On the back, the coat may become thinner. The dog becomes shy, does not tolerate bright lighting. The offspring of such an animal is born dead.

In young dogs, an acute course of the disease is often observed. By the behavior of the dog it is clear that she is experiencing severe pain. Its temperature rises to 41.5 ° C. Urine darkens, diarrhea develops with the presence of blood. Mucous surfaces turn yellow. In some cases, the disease develops very quickly, the outcome can occur within 2-3 days.

Latent, chronic, acute scenarios of the development of the disease can exist in two versions: hemorrhagic (bleeding, anicteric) and icteric. Variants have many common features, but are characteristic of dogs of different age categories.

Hemorrhagic form of leptospirosis

It is characterized by bleeding of the external and internal mucous membranes. This is due to the effect of endotoxins on the walls of small vessels. About half of the animals suffering from bleeding leptospirosis can die. The outcome depends on the occurrence and development of concomitant diseases and the dynamics of the course of the disease. The sharper the shape, the less likely it is to recover.

In some cases, the symptoms take on a “blurred” character: the disease gradually turns into a sluggish form. The dog remains inactive, the specific signs of leptospirosis subside. After a few days or weeks, the symptoms of infection reappear. The disease proceeds in waves.

About the third day, the mucous membrane begins to bleed, including internal organs. This can be seen by the presence of blood clots in the dog's secretions. She may have a fever, diarrhea and constipation. The general condition of the animal is deteriorating. A dog not receiving treatment dies.

Icteric form of leptospirosis

Most of all, young animals are affected by this form. Leptospirosis of dogs in the photo, with this development of events, it is distinguished by staining of mucous and skin surfaces in shades of yellow. Which does not mean the impossibility of bleeding manifestations. Hemorrhage and jaundice can exist simultaneously.

In addition to increasing bilirubin in the blood, there is swelling of the liver tissue, degradation and death of the parenchyma, as well as the destruction of red blood cells. Pronounced jaundice does not always lead to acute hepatic dysfunction. Acute renal failure occurs more often.

Is leptospirosis dangerous for humans

Human infection occurs while caring for animals, consuming raw milk, contacting dog excrement, swimming in lakes and ponds. The causative agent enters through unwashed hands, the use of raw milk from a sick animal, when water is swallowed from a reservoir, or the pathogen penetrates through scratches, mucous membranes of the nose or eyes.

The direct transmission of the pathogen from person to person is unknown.

The insidious contagion consists in the multiplicity of serotypes. If a person has had one type of leptospirosis, he is defenseless against others. If untreated, death is possible.

Stages and forms of the disease

In the development of the disease, 2 stages are distinguished:

  1. Bacteriemic - leptospira is found in the blood. The first signs: the dog is depressed, temperament, refuses to eat. On 2-4 days after the onset of clinical signs, the temperature returns to normal. This stage lasts from 2 days to 2 weeks, after which the dog recovers, the disease becomes chronic or the next stage of acute pathology develops.
  2. Toxic - microorganisms die. Decomposition products cause severe intoxication. Internal organs cease to function, the animal dies.

The following types of leptospirosis are distinguished by the rate of increase of pathological symptoms:

  • acute - lasts 1-4 days, high mortality,
  • subacute - the symptoms increase over 10-20 days, ends with death or a transition to a chronic form,
  • chronic, lasting from one to many months, characterized by periods of exacerbations and remission,
  • leptospironosis is an asymptomatic course of the disease in which a clinically healthy dog ​​releases bacteria into the environment, infecting others.
At the toxic stage of leptospirosis, the dog loses interest in what is happening.

The toxic stage of leptospirosis occurs in hemorrhagic or icteric forms.


Anamnesis, symptoms allow a fairly confident diagnosis. But laboratory studies play a dominant role. The most used method is serological analysis. With the help of this study, all types of pathogenic leptospira are recognized.

In addition to traditional methods, modern analysis of leptospirosis in dogs includes 2 tests:

  • fluorescence testing of antibodies and antigen,
  • polymerase chain reaction (amplification of DNA molecules).

These methods can be used to examine the urine of a sick animal and tissue samples. When taking samples and conducting analyzes, the fact must be taken into account that from the onset of the disease until the appearance of leptospira in the urine several days pass. A more reliable source of information is tissue samples obtained by biopsy.

Polymerase chain reaction is a new method of reproduction (amplification) of DNA molecules, which allows you to confidently identify the causative agent of the disease. The sensitivity of the test can lead to a false positive if the samples taken for analysis are contaminated. The method is quite new, it is not always included in the diagnostic arsenal of veterinary clinics.

Even on time treatment of leptospirosis in dogs does not guarantee a positive result. Some animals are completely cured, others die, and others may suffer the effects of the infection for life.

Therapy of leptospirosis solves several problems:

  • elimination of leptospira infection pathogens in the body,
  • Normalization of the functioning of the animal’s body, including the removal of signs of intoxication,
  • increase the immune potential of the animal.

Immediately after confirming the diagnosis, the body begins to detox in order to cleanse the bacteria and toxins produced by them. The basic is a course of antibiotic treatment. This speeds up the treatment of liver and kidney disease, reduces urine output.

Antibiotics remove bacteria from the kidneys. After that, leptospira cease to spread with urine. In addition, to restore the functioning of the liver, kidneys, blood vessels, heart, complex therapy is used: hepatoprotectors, vitamins, diet, cardiac stimulants.

It is extremely difficult to achieve a complete cure for leptospirosis in a dog


Preventive measures will help in the fight not only with leptospira, but also with most pathogens of infectious diseases:

  • Timely vaccination and immunization of dogs.
  • Fighting rodents.
  • Sanitary treatment of dogs, especially in shelters for stray cats and dogs.

Dogs and puppies can secrete pathogenic bacteria for many months from recovery. Owners of invasive dogs should consider this fact and isolate their pupils until analyzes show the absence of leptospira.

How and how to treat

Leptospirosis is a disease that threatens a person’s life, so entrust the treatment to specialists in a hospital. If you live in an area unsuccessful due to illness, are fond of hunting, travel with a pet - take care of yourself, get vaccinated.

In the early days of the disease, the dog can be administered medications intramuscularly or subcutaneously. In the future, there is a violation of local blood circulation and drugs from injection sites will be poorly absorbed into the blood. Therefore, intravenous drip of drugs is preferred. Leptospira live in the renal tubules, which are poorly supplied with blood. Therefore, antibiotic therapy does not always lead to the expected result.

The therapeutic strategy for treating leptospirosis in dogs is developing in the following areas:

    Destruction of the pathogen. In the early days of the disease, hyperimmune serum is administered 3 consecutive days.At the first stage, prolonged antibiotics of the cephalosporin or penicillin series are effective. If the disease has transformed into a chronic form, treatment is continued with other antiseptics. Tetracyclines destroy leptospira, however, are characterized by side effects - they prevent the restoration of local blood flow. Injections of Bicillin 3 or 5, practiced in previous years, are ineffective due to a violation of local blood circulation. At the same time, immunocorrectors are introduced - Polyoxidonium, Likopid, Ribotan, Gamavit.

With leptospirosis, intravenous administration of medications is indicated.

  • Dehydration control. The onset of the disease is characterized by thirst. Subsequently, debilitating vomiting develops. The dog swallows the water and immediately vomits it. So that the animal can drink, the regurgitation is stopped by parenteral administration of Metoclopomide (Cerucal). Osmoprotective salts are added dropwise:
    1. Ringer-Locke solution with glucose,
    2. Hemodez,
    3. Reopoliglyukin,
    4. Lactosol.

    When the dog can drink, stop diarrhea by oral administration of sorbents - Enterosgel, Smecta, Polyphepam.

  • Restoration of local blood circulation. Multivitamin preparations containing ascorbic acid are used, as well as general strengthening agents - Gamavit, Dufalight or Hemobalans.
  • Support for cardiac activity. The veterinarian prescribes Riboxin, Sulfocamphocaine, Thiotriazolin.
  • Recovery of the liver and kidneys. Detoxification therapy drugs are used - Karsil, Sirepar, Essentiale forte, Lespenefril and analogues on the background of diet therapy.
  • Clinical nutrition - a weakened body requires easily digestible nutrients that create sparing conditions for the functioning of internal organs. Feeding begins after daily fasting or when the dog is able to eat. I do not advise you to experiment, get medical nutrition.
  • Hills Veterinary Feed k / d is prescribed to animals with diseased kidneys and hearts. They contain protein hydrolysates, dried chicken eggs. They are characterized by a low concentration of complete easily digestible proteins and high calorie content. One can contains a daily portion for a pet weighing 30 kg. Note that after opening the canned food you need to feed for 36 hours or less. If you have a small dog - get Hills k / d pellets and soak them for the first time.

    The duration of diet therapy is determined by the doctor. A can of 370 g cans costs 261 p., Packing of dry granules of 2 kg - 1517 p.

    Can I be vaccinated against leptospirosis?

    To be vaccinated against leptospirosis is not only possible, but also necessary. If you live in an area safe for leptospirosis, do not flatter yourself. Tomorrow, well-being may disappear, because there are many carriers of infection - rodents, stray dogs and cats.

    Complex and monovaccines against leptospirosis have been developed for dogs.

    A vaccination schedule for Nobivak vaccines has been developed. The figure shows that immunization of puppies against plague, enteritis, hepatitis (DHP) and leptospirosis is carried out simultaneously at 8-9 weeks and fixed at 84 days. Biopreparation DHPPi (Pi parainfluenza) and RL (rabies plus leptospirosis) are used. Adult dogs are vaccinated annually, once, according to the same scheme as twelve-week-old puppies. If recommended by a veterinarian, additionally immunize your pet against leptospirosis with a monovirus.

    I anticipate the question: “Can leptospirosis occur in a vaccinated dog, and if so, what are the symptoms? I answer: there are no vaccines that provide one hundred percent protection.

    • vaccination during the incubation period,
    • individual characteristics of the dog,
    • crowded content in the nursery,
    • the dog was infected with the serotype of leptospira, the antigens of which are not present in the biological product.

    • violation of storage and (or) transportation rules,
    • non-compliance with quarantine measures - you decided to walk with the dog before the bactericidal antibody titer was formed,
    • vaccination without preliminary deworming,
    • improper maintenance and feeding.

    Symptoms of the disease in the vaccinated dog are erased.

    Is it possible to cure without consequences?

    An ill dog gains a lifelong immunity. However, no one can guarantee that the dog will not subsequently manifest any disease. It is impossible to determine what it is: the consequences of leptospirosis, an independent pathology, or a symptom of another disease.

    Therefore, be prepared for the fact that the pet will eventually have health problems. Notify your veterinarian when collecting an anamnesis that a dog has had leptospirosis.

    What tests are done to diagnose leptospirosis?

    Leptospirosis analysis consists of biochemical and serological studies of blood and urine. The veterinarian will take a blood sample, you will need to collect urine. It should be warm and fresh, taken less than two hours ago. If leptospirosis is suspected, the sample is sent to a state laboratory.

    Consequences and Complications

    Leptospira have a destructive effect on the body. Pathological symptoms can remain for life, not appear at all or alternate with periods of remission. The most common complications are:

    • liver cirrhosis, hepatitis, hepatosis,
    • chronic renal failure
    • digestive disorders
    • cardiovascular pathology,
    • corneal ulcers
    • keratoconjunctivitis,
    • paresis, paralysis.

    Leptospirosis is a dangerous disease that is difficult to treat. The dog in most cases dies or becomes disabled. When caring for a sick pet, you yourself risk becoming infected if you do not strictly observe personal hygiene rules. Therefore, I advise you to think about the safety of your pet. The most reliable way is vaccination.