Cat Scratch Fever in Cats: What Is It and How Is It Treated?

What Is Cat Scratch Fever in Cats?

Cat scratch fever is a disease in cats caused by the bacterium Bartonella henselae, which is spread through flea bites and cat scratches.

Affected cats experience symptoms like swollen lymph nodes, lethargy, and a reduced appetite.

It can affect cats of any age, but it is most common in kittens, adult community cats, and those with weakened immune systems.

When fleas bite infected cats, they contract the bacterium and then shed it in their droppings, which are found on the cat’s fur.

When cats scratch themselves, they can get these droppings underneath their claws and spread the infection to another cat through a scratch.

Most cats with cat scratch fever do not have symptoms. However, if symptoms do develop, the cat should be brought to a veterinarian promptly for appropriate treatment.

This is especially important since this disease is zoonotic, meaning it can be spread from cats to their human pet parents. 

Symptoms of Cat Scratch Fever in Cats

While most cats with cat scratch fever do not actually develop any symptoms, some cats—such as young kittens and cats with weak immune systems—may experience the following:

• Lethargy

• Decreased appetite

• Swollen lymph nodes

• Fever

• Vomiting

• Reddened eyes

• Blister or bump on skin (where scratch occurred)

Causes of Cat Scratch Fever in Cats

Cat scratch fever can be caused by any of the following:

• Flea bites

• Scratches or bites from infected cats

• Blood transfusions

Cats that are not up to date on flea and tick preventatives are at the highest risk of contracting this disease.

Cats with weak immune systems, such as kittens and those with chronic diseases like FeLV, may also be more likely to become infected.

How Veterinarians Diagnose Cat Scratch Fever in Cats

A veterinarian will start with a physical exam to check your cat’s overall health and identify abnormalities.

During this time, pet parents can discuss their cats’ concerning symptoms, whether they’re current on flea and tick preventatives, and if their cats have had any recent exposure to other cats.

If the veterinarian suspects cat scratch fever, testing can be done to support a diagnosis, which may include:

• Blood work: A small sample of the cat’s blood is collected to check for signs of infection, such as increased white blood cells or liver enzymes.

  • Blood can also be used for more advanced testing, such as PCR or ELISA, to see if antibodies against B. henselae are present.

• Bacterial culture: If blood work shows signs of infection, a blood sample can be sent to a special laboratory to identify which type of bacterium may be the culprit.

• Lymph node aspirate: The veterinarian uses a small needle to poke and gently collect a sample from a cat’s swollen lymph node.

  • The sample can be placed onto a glass slide and viewed under a microscope to identify if any cells that indicate infection are present.

Treatment of Cat Scratch Fever in Cats

Most cats do not require treatment. Cats with healthy immune systems are generally able to fight the infection themselves.

However, in cats with weakened immune systems or severe symptoms, treatment may be necessary.

Treatment consists of antibiotics for four to six weeks. Common antibiotics used include doxycycline and enrofloxacin. Although antibiotic treatment generally eliminates this bacterium, cats can become re-infected if fleas are not properly addressed as well.

Cats should be treated with a topical or oral flea preventative such as Bravecto® or Revolution® to eliminate fleas.

Recovery and Management of Cat Scratch Fever in Cats

Because many cats do not have any symptoms, they generally recover well on their own with time. Cats who develop symptoms typically start feeling better just a few days after initiating antibiotic treatment.

However, it can take one to two months for all symptoms, especially swollen lymph nodes, to fully resolve. Pet parents should always give antibiotics exactly as prescribed by their veterinarians for best treatment outcomes.

During recovery and in the initial post-treatment period, it is important to prevent re-infection for cats.

Pet parents should ensure they have administered flea preventative and that they do not allow any close contact with currently infected cats.

Prevention of Cat Scratch Fever in Cats

Cat scratch disease is a preventable condition. To keep their cats healthy, important steps pet parents should take include:

• Keeping cats on year-round flea prevention

• Avoiding contact with infected cats

• Preventing cats from biting and scratching one another