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Bartonella Infection In Dogs – Symptoms, Causes, And Diagnose

Margarita Boyd
Written by: Dr. Margarita Boyd, BVSc MRCVS
Bartonellosis is a zoonotic disease, meaning it can easily affect both a dog and a pet owner. This bacteria can lead to severe infection in organs and various tissues. Read on to learn to recognize the symptoms.

Bartonellosis is a serious infectious disease found worldwide, caused by the bacteria Bartonella. It is a zoonotic infection, meaning the disease can spread between animals and humans.

The bacteria live inside red blood cells and can be transmitted to dogs by a variety of parasites including fleas, lice, sand flies and ticks.

This disease can cause lots of health problems for both dogs and humans, so it’s important that you can take steps to prevent infection and be able to recognize the signs. That way you can be fully prepared to protect your beloved dog!

Is your pooch at risk of this infectious disease? In this article, we will discuss everything you need to know. We will look at the signs of Bartonella infection in dogs, diagnosis, treatment and how you can prevent your dog from getting infected.

What Is Bartonellainfection?

Bartonella is a small, rod-shaped, gram-negative bacteria that live in the red blood cells in the bloodstream of infected animals.

In dogs, it is transmitted through blood-sucking insect vectors such as fleas, ticks, lice, and biting flies. (1)

Bartonella infection is also known as bartonellosis, cat scratch disease, trench fever of Carrión’s disease. There are more than 36 different Bartonella species of bacteria, that are spread throughout the world.

Bartonella henselae and Bartonella vinsonii subspecies berkhoffii are the most commonly found bacterial species in sick dogs (2).

How Are Dogs Infected With Bartonella?

Dogs can be infected with this disease through a bite from a flea, tick, lice or sand fly that is carrying the Bartonella bacteria.

The bacteria are then transferred into the dog’s bloodstream, where they tend to hide in red blood cells before moving to other parts of the dog’s body.

Are Some Dogs More At Risk Than Others?

Dogs that live or travel in tropical areas are at a higher risk, as up to 65% of dogs in these areas are seropositive (infected). While in temperate or cold climates the rate of infection is thought to be as low as< 5% (3).

Fleas and ticks seem to be the most common vector for transmission of this infection in dogs. Dogs living in rural areas, hunting dogs, or dogs that regularly go to rural areas for hiking, camping or walking, are at an increased risk of catching the disease.

If your dog is infected with Bartonella his immune system might just fight off the infection and show no clinical signs. However, he is at higher risk of having health problems with the infection if he:

  • Has a weakened immune system
  • Has other health problems
  • Underweight or fed a poor diet
  • Taking immunosuppressant medications

In these cases, the dog’s body will struggle to fight off the Bartonella bacteria. This means he would be at a higher risk of developing some serious health issues with this infection! (4).

What Are The Signs Of Bartonella Infection In Dogs?

Different Bartonellaspecies of bacteria will cause different signs in dogs. Some dogs may become infected and only show mild signs of sickness, or they might not show any signs of sickness at all.

Other dogs may become infected and have long term signs of illness for months or years later.

The signs of Bartonellosisin dogs can include:

  • Fever
  • Weight loss
  • Decreased appetite
  • Weakness
  • Lack of coordination (ataxia)
  • Seizures
  • Difficulty breathing
  • Lameness and Joint pain (often intermittent)
  • Nasal discharge or nose bleeds
  • Skin problems
  • Swollen lymph nodes
  • Jaundice (yellowing of the skin, eyes, mucous membranes)
  • Heart problems or an irregular heartbeat

The signs of Bartonella infection in dogs can be vague or non-specific and can be similar to other many diseases or health problems.

What Health Problems Can Bartonella Cause In Dogs?

Bartonella bacteria are pretty darn smart as they can hide in red blood cells or endothelial cells (the lining of the blood vessels). Then they can move on to set up a permanent position in places like the lymph nodes, liver, spleen, kidney, skin or bone marrow (5).

Common health problems these bacteria can cause in dogs include:

  • Endocarditis: Infection of the inner lining of the heart (endocardium) and lining of the heart valves.
  • Myocarditis: Also known as inflammatory cardiomyopathy, this condition is due to inflammation of the heart muscles.
  • Polyarthritis: Inflammation, pain, and swelling of multiple joints in the body.
  • Encephalitis: Inflammation (swelling) of the brain.
  • Lymphadenomegaly: Enlargement of the lymph nodes in the body.
  • Uveitis: Inflammation of parts of the inner eye, which can lead to blindness.
  • Vasculitis: Inflammation of the blood vessels, causing changes to the walls of the blood vessels.
  • Dermatitis: Inflammation or redness of the skin.

So, it’s obvious that some of the health problems can be pretty serious if the infection is left untreated.

What To Do If You Think Your Dog Has Bartonella Infection?

If you think your dog is showing signs of a Bartonella infection, then it is important to take your dog to your veterinarian. Your vet will be able to diagnose the problem and offer advice.

Unfortunately, there is no effective natural remedy or home treatment to cure this bacterial infection.

Cats are known as a “reservoir” of infection and can transmit the infection to humans through bites, scratches and flea dirt. However, it’s not fully understood yet if dogs with Bartonella infection pose a threat to humans, or if the infection can be passed easily from dogs to humans (6). If you are concerned, then you should talk to your medical doctor.

How Is Bartonella Diagnosed In Dogs?

Diagnosing bartonellosis in dogs can be a challenge as the clinical signs are not very specific, and the bacteria tend to “hide” in red blood cells which makes them difficult to detect.

A veterinarian will complete a full physical examination and ask questions about the dog’s history.

The vet will then usually recommend some further tests to help determine the cause of the dog’s problems. These tests may include:

1. Complete Blood Count

This checks the levels of the red blood cells, white blood cells, and platelets. It can identify problems such as anemia (low red blood cells), thrombocytopenia (low platelet levels), signs of infection or even certain cancers.

2. Blood Biochemistry

This checks the health of some organs in the dog’s body including the liver and kidneys. It can also assess the levels of calcium, glucose, proteins, fats, metabolic function and salts (sodium, potassium, and chloride) in the dog’s body.

3. Urinalysis

An assessment of the urine can check for signs of a urinary tract infection, red blood cell problems and assess the function of the kidneys.

If bartonellosis is suspected, then further specific laboratory tests can include:

4. Culture Test

A culture test is used to check for a bacterial infection. If bartonellosis is suspected, then most commonly a blood sample is taken from the dog and submitted for a blood culture test to check for bacteria.

However, cerebrospinal fluid, joint fluid or tissue biopsies can also be used.

5.PCR Assay

This test checks for the Bartonella specific DNA in the dog’s blood or submitted samples.

6. Serology Test

This blood sample test checks for specific antibodies that the dog produces against Bartonella after it has been infected.

What Is The Treatment For Bartonella In Dogs?

If a dog is showing signs of Bartonella infection, and the diagnosis has been confirmed, then the dog will be prescribed antibiotics. Most dogs can continue their treatment at home and will be given a course of oral antibiotic tablets.

However, in some severe cases (e.g. dogs with endocarditis, myocarditis, encephalitis) the dog may require intensive treatment, hospitalization, and intravenous antibiotics.

Antibiotics are the main treatment for bartonellosis in dogs, and most dogs will require a combination of different antibiotics for at least 4-6 weeks. However, there is no standardized treatment protocol established yet for dogs with Bartonella infection.

Commonly used antibiotics for the treatment of this infection in dogs include azithromycin, doxycycline, enrofloxacin, and rifampin. The antibiotics chosen will depend on the severity of the clinical signs and the location of infection within the dog’s body.

Are There Any Risks With Treatment?

The antibiotics commonly used to treat bartonellosis can cause some side effects including:

  • Decreased appetite
  • Vomiting
  • Diarrhea
  • Increased liver enzyme activity

On days 3-6 of antibiotic treatment its pretty common for dogs to show signs of lethargy and decreased appetite. Its thought these side effects are due to the high numbers of Bartonella bacteria dying off.

Sometimes the treatment doesn’t work which may be due to the antibiotics not working, the owner not finishing the course of antibiotics, or not sticking to the medication schedule.

Your vet should discuss the possible side effects of the medications, what you should expect and when you should seek veterinary attention.

Is There Any Follow-Up/Monitoring After Treatment?

Your dog will need to be closely monitored during and after the treatment for Bartonella infection. Usually, a complete blood count and blood biochemistry are performed two weeks after the antibiotics are started to check for any abnormal side effects of the treatment.

To confirm that the treatment has been successful, and the Bartonella bacteria have been eliminated, a blood culture/PCR assay is usually completed two weeks after the course of antibiotics has finished.

Your dog should be monitored after treatment for the re-occurrence of clinical signs and should be retested as necessary.

What Is The Prognosis For Bartonella Infection In Dogs?

This is not usually a fatal infection in dogs, but the secondary problems that the bacteria can cause can lead to serious health problems.
Prognosis varies from good to grave, depending on the disease process and the dog’s response to antibiotics.

Can Humans Be Infected With Bartonella?

Yes, humans can become infected with Bartonella. Many Bartonella species are zoonotic, meaning they can cause disease in people and animals, and infection can be passed from animals to humans.

In humans, Bartonella infection is commonly known as cat scratch disease, as it is most frequently transmitted through scratches or bites from domestic or feral cats. Cats usually become infected from fleas that carry the Bartonella bacteria. Humans can also be infected with other types of Bartonella bacteria, through lice and sandfly bites. (7)

If you are bitten by a cat, it is very important to seek medical attention. Seek advice from your doctor if you are concerned about Bartonella infection for you or your family.

Can Bartonella Infection Be Prevented In Dogs?

Thankfully there are some ways to help protect your dog from getting infected with Bartonella infection, including:

  • Use effective flea prevention
  • Use effective tick prevention
  • Use effective sand fly prevention
  • Check your dog for fleas and ticks daily
  • Take extra precautions if hiking or camping in high-risk areas
  • Talk to your doctor about how to protect you and your family from getting Bartonella infection.

Any cats in your household also need to be treated with an effective year-round flea and tick treatment too. Cat fleas, flea dirt and cat scratches are major routes of transmission of this disease between cats and humans.

Your vet can help you choose a safe and effective parasite prevention protocol to protect your dog all year round. Over-the-counter, non-veterinary products or natural remedies are not very effective, and may even cause your dog harm as they are not regulated.

Bartonella Infection In Dogs Conclusion

Bartonellosis is an emerging disease that we are only starting to understand and treat effectively. It poses problems as it can be difficult to diagnose, as the cunning bacteria can hide in red blood cells, and spread throughout the body causing intermittent signs.

Sometimes Bartonella infection can cause no signs at all in healthy dogs, and in other cases, it can cause severe, chronic problems for the infected dog.

Early diagnosis and veterinary treatment are key to a good long term prognosis. This is a zoonotic disease, meaning it can spread between animals and humans. Therefore, it is important to talk to your doctor and take measures to protect yourself and your family.

Your veterinarian can help you choose safe and effective parasite preventive options to protect your dog year-round from Bartonella and many other parasitic infections.