Tularemia (rabbit fever): what are the causes and treatments?

Tularemia is a condition caused by the bacterium Francisella Tularensis, which strikes wild animals and, these, transmit it to humans.

Symptoms include ulcerations and the appearance of lymph nodes (structures of the immune system), which can be classified among the 7 types of presentation of the condition.

Are you curious to know more about the diagnosis and possible treatments for this disease?


What is tularemia?

Also known as rabbit fever , tularemia is a bacterial infection resulting from Francisella Tularensis.

This condition first affects animals, such as rabbits, sheep and cats, and is transmitted through the bite of ticks or the deer fly (large fly that feeds on blood). In addition, infection can occur through eating or handling contaminated meat.

The diagnosis of this condition is essentially clinical, however, it must be rigorous and careful, since tularemia is confused with several other possible conditions that have the same symptoms.

It can be found at ICD-10, using the following codes:

  • A21: Tularemia;
  • A21.0: Tularemia ulceroglandular;
  • A21.1: Tularemia oculoglandular;
  • A21.2: Tularemia pulmonar;
  • A21.3: Tularemia gastrointestinal;
  • A21.7 : Generalized tularemia ;
  • A21.8 : Other forms of tularemia;
  • A21.9 : Tularemia, unspecified form.

Tularemia in Brazil

Tularemia is a condition that presents itself mainly in the United States. Natural cases of tularemia occur in North America, Europe and Asia. There are still no records of this condition in Brazil.

Types of tularemia

Tularemia can present itself in seven different ways, its differences being related to the infected sites and the way it presents itself in the body.


This is the most common type of infection. Contamination occurs through skin wounds (cuts, bites).

Recurrent symptoms of this type are ulcers, which cause swelling in the fingers and lymph nodes (small glands in the lymphatic system), in addition to pain and, eventually, pus.


In this type it is possible to perceive the formation of lymph nodes, which possibly swell and become painful, however, without presenting ulcerations.


Caused by contact of the contaminated hand with the eyes, this type of tularemia can cause swelling in the eyes, in addition to local redness, pain and, in some cases, the appearance of pus.


Considered a little rarer, this condition specification is linked to the consumption of contaminated meat. The pharynx has inflammation and the lymph nodes in the neck swell, which can cause nausea, vomiting, diarrhea and abdominal pain.


This condition presents itself when the bloodstream is already infected. This type of tularemia can cause fever, chills, abdominal pain, however, without any type of ulceration or lymph nodes.


This condition is due to the direct inhalation of bacteria or when there is an infection in another part of the body and the agents reach the lungs through the bloodstream.

The person may have a dry cough , chest pain and shortness of breath. It can develop between 10% to 15% of people who already have ulceroglandular, and 50% in people with the typhoid type.


This is considered to be the rarest and most serious type of the condition. It occurs when the bacteria has already spread through the bloodstream, affecting the entire organism and causing the malfunction of several organs.

Among the main symptoms of this specific type, we can mention: drop in blood pressure, accumulation of fluids in the lung and bleeding caused by the decrease in the production of coagulants in the body, due to the bacteria itself.

Causes: what is Francisella Tularensis

Tularemia is a condition caused by a bacterium found in small animals, known as Francisella Tularensis.

Considered to be highly capable of infection and contamination, a small number of agents are required to cause disease in humans.

The disease can develop due to the bite of ticks infected with the agent or through the ingestion of contaminated food or water. It mainly affects small animals, such as rodents, cats, rabbits and sheep.

How does transmission occur?

There are 3 possible types of ticks responsible for the transmission of tularemia, they are: dog tick, American dog tick and the lone star tick, which can bite humans and transmit the agent.

In addition to these, the other possible transmitter of the condition is the deer fly .

But it is also possible to contract bacteria by direct contact with it, in which the agent can infiltrate the body through the eyes and mucous membranes or lungs. Usually, it occurs when a person touches or manipulates infected animals, such as rabbits and squirrels, and even those that are domestic, but that are loose in open environments, such as parks and lawns.

More rarely, contagion can occur through ingestion of contaminated water or food. But, remembering, that the agent cannot be transmitted directly from person to person.

Risk factors

As it is a condition that is linked to wild animals and to external environments, some specific activities or exposures can be considered risk factors for the development of the condition. Among them we can mention:

  • Hunting or capturing wild animals;
  • Work on farms or farms;
  • Consuming meats without proper preparation and hygiene.

Symptoms: what defines tularemia?

The symptoms of this condition will vary between the ways in which each person contracts tularemia, differentiating between mild to severe.

They usually take 3 to 5 days to develop, and may take up to 21 days to manifest. The most common symptoms are as follows:


The first symptoms of tularemia are similar to those of a cold . Therefore, it is possible to have fever, headaches, chills, sore throat and loss of appetite. This is essentially because the organism is being infected by a bacterium, so your first reaction is those mentioned.

Abdominal pain

This symptom is most frequently present in contamination due to the ingestion of undercooked meat or contaminated water, known as oropharyngeal tularemia. In some cases, it is possible to experience gastrointestinal bleeding.


Ulcerations are lesions or wounds that appear on the skin. This symptom is present in about 75% to 85% of the cases, with characteristics and appearance of an insect bite.

It can itch and develop a black base. It takes around 1 to 3 weeks to start healing.

Swollen lymph nodes

Depending on the affected area, tularemia can cause swelling of lymph nodes, also called lymph nodes, which are part of the immune system. May have pus on the spot, pain and lead to tissue necrosis.

Other symptoms

In addition, the condition can cause the following symptoms:

  • Headache;
  • Sore throat;
  • Abdominal pain.

How is the diagnosis made?

Tularemia is a condition that has a complicated diagnosis, since its symptoms can be confused with another disease.

Therefore, when seeking medical help, be sure to mention your work, places of exposure, as well as probable contacts with wild animals.

The ideal is to seek a general practitioner or infectious disease to identify the symptoms mentioned above.

To confirm the diagnosis, blood collection and other possible tests may be requested, such as:

Chest X-ray

Assists in the diagnosis and evaluation of the doctor. The interpretation takes place according to the image produced, which can be considered normal or which is pathological. This test can be used to assess areas other than the chest, such as the abdomen, spine, shoulder, among other regions.

Examination of body fluids

This test aims to count leukocytes (white blood cells), in addition to the presence and concentration of other cells and substances.

It can be done with secretion samples, saliva and even feces.

However, this examination must be performed with special precautions, since the samples may contain Francisella Tularensis .

Skin exams

These tests can be ordered when the cause of the condition is not yet fully evident to the attending physician.

Among the options, it is possible to perform scraping, biopsy, wood light, Tzanck test and diascopy, which consist of the removal of a small sample of skin, followed by laboratory analysis.

Blood fluid culture

According to the CDC, blood fluid culture remains the main way of identifying tularemia. However, because it is a slow-growing bacterium, Francisella Tularensis can only be noticed 24 to 72 hours after having infected the organism.

For the exam, a blood sample is taken, by means of a common exam.

Is there a cure?

Yes. However, for this it is necessary to strictly follow the treatment indicated by the doctor, since tularemia is considered a serious condition and, in some cases, can lead to death.

What is the treatment?

The main form of treatment for tularemia is related to the association of antibiotics , which usually lasts around 10 to 20 days of treatment. In some cases it may be necessary to drain the ganglion.

Drug therapy

Drug treatment may vary according to each case and symptoms. However, it is recommended to use antibiotics, such as Doxycycline Hydrochloride, in which it may be indicated to use single doses or to keep using them every 12 hours, for 7 days.

Ganglion drainage

Drainage aims to eliminate plasma proteins , in addition to metabolic remains. With this, it is possible to increase the volume of body fluids, in addition to providing maintenance of the immune system.

This procedure must be performed by a specialist doctor, in the office. It is recommended to observe if that ganglion has remained swollen for more than 14 consecutive days, and then think about performing the drainage.


Because it is a condition caused by bacteria, the ideal treatment for tularemia is to use antibiotics. They can be used:

  • Doxycycline Hydrochloride;
  • Streptomycin ;
  • Gentamicin ;
  • Doxycycline Hydrochloride .

These drugs can be used in two ways, everything will depend on the medical recommendation. You can use a single dose with 100 mg or the same dose, only prolonged, being administered for 7 days.


NEVER self-medicate or stop using a medication without first consulting a doctor. Only he will be able to tell which medication, dosage and duration of treatment is the most suitable for his specific case. The information contained on this site is only intended to inform, not in any way intended to replace the guidance of a specialist or serve as a recommendation for any type of treatment. Always follow the instructions on the package insert and, if symptoms persist, seek medical or pharmaceutical advice.

Living together

During the days when fever and fatigue are present , the ideal is to rest at rest to recover your energy. In addition, it is essential to always stay hydrated, drinking an average of 2 liters of water per day.

Another important factor in living with tularemia is maintaining a balanced diet, making the intake of vitamins and minerals.


The chances of a cure are great for patients who follow the treatment correctly. However, without the correct procedures, the ulceroglandular type reaches a 6% mortality rate, and in cases of typhoid, pneumonia and septicemia even more, reaching almost 35% mortality rate.


If not treated properly, tularemia can cause complications and can even be fatal in some cases. Among the possible complications, we can mention:


When not treated properly, tularemia can cause inflammation of the lungs, leading to respiratory failure.

As a consequence, the organism may have a deficiency in the aspiration of oxygen or in the release of carbon dioxide.


The meningitis is a condition that corresponds to a severe inflammation that affects the meninges, a region around the spinal cord and brain.


This condition represents irritation and swelling around the pericardium, which is a thin membrane that covers the heart. In some cases, it may be necessary to introduce antibiotic therapy.


The osteomyelitis occurs when bacteria of tularemia have spread throughout the body, also reaching the bones and causing inflammation of the tissue.


The sepsis can be understood as a condition that occurs due to chemicals that are released into the blood stream to fight infection, causing widespread inflammation.

It is considered a possibly fatal complication, which can cause fever, difficulty breathing and mental confusion.

Its treatment is performed on the basis of antibiotics or intravenous fluids.

How to prevent tularemia?

The condition can be prevented by protecting yourself from direct contact with insects, such as mosquitoes and ticks. For this, one way to prevent infection is to avoid direct contact with dead animals, which we will explain further below:

Avoid contact with sick or dead animals

This is the main form of contamination from tularemia. Therefore, whenever you come into contact with dead animals, carcasses or wild animals, double the care and attention. To do this, make sure you wear goggles, masks and long clothes.

Cook the meat properly

Another form of contamination that is easy to avoid is through the consumption of contaminated meat. To avoid infection, double your attention when cooking food.

Use tick repellent

Another easy and widely accessible tip is to use repellents whenever you are in an open environment, such as woods, farms and farms. It is important that the repellent is 20% or 30% DEET.

Tularemia in cats and rabbits

Cats and rabbits can contract tularemia through food, either by eating a bird, a mouse or even through the airways.

You need to be aware that, once infected, your pet can transmit this condition for up to two years after contracting tularemia.

The symptoms are basically the same as that of humans, that is, lack of appetite, fever, lethargy, ulcers and inflammation in the lymph nodes.

To protect them and possibly prevent the disease, talk to a veterinarian about methods and care.

Common questions

Why is tularemia called rabbit fever?

The condition can be known in this way since the main transmitter of the disease are rabbits and felines, such as domestic cats. In addition, because the initial symptom was an abrupt fever, the condition became known as rabbit fever.

How does tularemia spread?

Tularemia is a condition that has no aspect of transmission from person to person. However, care must be taken since it can be acquired through the bite of insects, such as mosquitoes and ticks, in addition to eating contaminated food and drinks.

Another possible form of transmission is by handling carcasses or hunting animals.

How long does it take for people to experience symptoms?

It usually takes about 3 to 5 days, once contact with the bacteria has occurred.

Can tularemia kill?

-Yeah . Tularemia is a condition that, without proper treatment, can cause a variety of complications. Consequently, these can lead to complications, which can eventually lead to death.

Is there a vaccine for tularemia?

No . That is why we reiterate the importance of seeking a doctor as soon as the first symptoms are noticed, as starting treatment early, facilitates healing and reduces the chances of complications.

Do you know someone who has frequent contact with wild animals or who spends a lot of time in bush areas?

Then share this article with your friends, so that they also know about this condition!