Tularemia is a bacterial disease caused by Francisella tularensis. Although rare, dogs can contract this disease at any stage of their life. It’s also known as “rabbit fever” because it’s typically found in animals such as rabbits and rodents. In some cases, tularemia in dogs left untreated can become fatal, so it’s important to recognize the disease as soon as symptoms arise. Here’s a guide to the symptoms of tularemia and its causes, diagnosis, prevention, and treatment.
What is Tularemia?
Tularemia can affect a variety of animal species—including humans and dogs—and is acquired through contact with infected animals. The bacteria create tumor-like masses and abscesses in the liver of its host.
Dogs and other domestic animals are usually considered to be accidental hosts, and many dogs appear to be resistant to tularemia altogether. In fact, this disease is often seen more frequently in cats compared to dogs. In general, young animals are usually more susceptible to contracting this disease over older dogs. However, any dog who has been exposed to infected wildlife or domestic animals is at risk of contracting tularemia.
Tularemia is found throughout much of the world, including continental Europe, Japan, China, and the United States. In the U.S., the disease is found in every state except Hawaii, but it is most common in the states of Arkansas, California, Montana, Missouri, Oklahoma, and South Dakota. Incidents of tularemia tend to be higher across the country during the summer, when tick and deer fly are more populous, and in the winter, during rabbit hunting season.
Tularemia is a zoonotic disease, which means it can be passed from an animal or insect to a human, or from one species of animal to another. Zoonotic diseases cannot be transferred from person to person, but you can potentially contract tularemia from your dog. Symptoms of tularemia in dogs can take up to 10 days to present themselves, and the bacteria can remain alive for weeks or months without a host. It’s important that if you live in tularemia-prone areas or regions, that you take all the necessary precautions to mitigate the risks of contraction and keep both you and your dog as healthy as possible.
Types of Tularemia
There are two types of tularemia bacteria found in the U.S.
- Type A, Francisella tularensis biovar tularensis, is the most serious of the two and requires prompt medical attention; this type is commonly found in North America.
- Type B, Francisella tularensis biovar palearctica, is a milder version of the disease, and is typically associated with water contamination, aquatic mammals, and arthropods (ticks, fleas, or flies).
Causes of Tularemia in Dogs
Tularemia is contracted by exposure to an infected source—contaminated animals, water, or soil. Dogs can catch the disease by ingesting contaminated water or through contact with soil that is housing infected organisms, which can remain as an infection for several months.
Dogs can also be exposed to tularemia by killing and/or eating an infected animal, often a rabbit or rodent. When a dog ingests the tissue and body fluids of the animal, the bacteria will collect in his head, neck, and gastrointestinal system, and from there, systemic infection occurs.
The most common way dogs contract this disease is through a bite from an infected tick, mite, flea, or mosquito; the most common carriers are the American dog tick, the Lone Star tick, and the Rocky Mountain wood tick.
The tularemia bacteria can also infect a dog by entering his airways, eyes or gastrointestinal system, or through skin contact. The bacteria creates a blister in the skin three to five days after contact. When the blister begins to ulcerate, two to four days later, the bacteria can enter the lymph system, spreading to the rest of the body, including the lungs, liver, spleen, and bone marrow.
Inhalation of the aerosolized bacteria can also cause disease in the lungs.
Symptoms of Tularemia in Dogs
A dog with Type B tularemia, the mild form of the infection, will typically not present any symptoms. If they do, your dog can experience a lack of appetite, canine lethargy, or a low-grade fever for only a brief period.
Signs of the disease can include tick infestation, swollen glands and lymph nodes, a sudden high fever, lethargy, and poor appetite. Other signs may include:
- Abdominal pain
- Enlargement of spleen or liver
- Frequent urination
- High heart rate
- Increased panting or respiratory rate
- Reduced mobility
- Skin ulcers
- Throat infection
- Ulcers or white patches on the tongue
In more extreme cases, dogs can experience organ system failure or jaundice, which is the yellowing of the skin, eyes, and mucous membranes. If you see any of the symptoms of tularemia in dogs present in your canine, visit an emergency veterinary clinic immediately.
It can take 1-10 days from the initial exposure of the tularemia bacteria for symptoms to start appearing in your dog. Symptoms in humans follow a similar timeline and presentation, so if you suspect that you have contracted tularemia, you should see your doctor for treatment as well.
If you see any of these symptoms of tularemia in dogs, make an appointment with you vet as soon as possible. Early treatment of tularemia in dogs is essential for a positive outcome.
Prevention of tularemia in dogs (and you) essentially comes down to tick control. Make sure you check your dog for ticks on a regular basis, and use a tick and flea preventative, especially during the summer or after a hunting session (if applicable).
When outdoors in areas where rabbits or rodents are prevalent, keep your dog on a leash to keep him away from any dead animals. Also use an insect repellent on you and your dog while outside in situations where you’re more likely to encounter fleas or ticks. Consult with your vet if you are unsure what option to use.
Because infected animals can carry the disease even when dead, avoid handling them all together. If a dead animal must be moved, avoid direct contact with its carcass. Put on gloves, a long sleeve shirt, long pants, and closed-toe shoes. Use a shovel to move the animal, place it in a plastic bag, and dispose of it in an outdoor trash receptacle. Then wash your hands well immediately after.
If you hunt wild game like rabbits and rodents, handle the skin and carcasses with care. Wear gloves at all times. If an animal is infected, tularemia can live in its frozen meat for over three years, so be sure to cook it thoroughly to kill any remaining bacteria before consumption.
Diagnosis of Tularemia
For your vet to make the most accurate diagnosis, you will need to give them a thorough history of your dog’s health and recent activities. If he’s been boarded, on an outing, interacted with other animals, or traveled to places where insects are populous, it’s important that your vet knows. If your vet does suspect tularemia, they may specifically ask about the wildlife or common infection carriers your dog may have been exposed to in the last few weeks.
Unfortunately, there is no single, simple test for tularemia. When you take your dog to a veterinary clinic, your vet should perform a complete physical exam. A preliminary diagnosis based on your dog’s physical exam, medical history, and recent activities may prompt treatment even before the final diagnosis is completed. Although a bacterial culture test and lab work will still also be ordered.
In some cases, the diagnosis of tularemia in dogs is not so obvious and samples will need to have specialized laboratory services to confirm the presence of the disease. This will include lab work such as a blood chemical profile, complete blood count (CBC), blood chemistry panel, electrolyte panel, and urinalysis.
If tularemia is present, your dog’s test results will reveal a high white blood cell count, low blood sugar, low blood sodium, and low platelet levels (thrombocytopenia). There may also be blood in your dog’s urine.
If the blood tests reveal high levels of bilirubin (hyperbilirubinemia), this can indicate that liver damage is occurring. If this is the case, your dog will likely be displaying symptoms of jaundice. Liver damage can also lead to canine seizures, disorie