What is Cat Scratch Fever? (Symptoms & Treatment)

You likely know a song about cat scratch fever—but there’s a good chance your knowledge stops there. Cat scratch fever, also known as cat scratch disease or lymphoreticulosis, is a bacterial disease caused by the bacteria Bartonella henselae. It’s fairly common in cats, especially young cats and kittens. It’s estimated that up to 40% of cats have been infected with Bartonella henselae at some point in their life.¹

Cat scratch fever is a unique disease because it is not only passed from cat to cat, but can also be passed from cat to human.

Read on to learn all about cat scratch fever, what to look for, how to treat it, and how to protect your cat–and yourself!

• What Causes Cat Scratch Fever?
• Symptoms of Cat Scratch Fever
• Diagnosing & Treating Cat Scratch Fever
• Cat Scratch Disease Prevention
• FAQs
• Final Notes

What Causes Cat Scratch Fever?

Cat scratch fever is transmitted from one infected cat to another—though not always directly. Bartonella henselae, the bacteria that causes cat scratch fever, is carried in blood, saliva, and waste. Therefore, cats can contract cat scratch fever from:

• Flea bites: A flea may bite an infected cat and transfer the bacteria via saliva to another cat that it bites.
• Flea dirt: A flea that carries cat scratch disease can shed the disease in its feces, known as flea dirt. A cat can then contract the bacteria from flea dirt through its mucus membranes, an open wound, or may even get the dirt on its nails and scratch itself.
• Cat scratches: Cat scratch disease can, of course, be transferred from one cat to another via cat scratch or bite.
• Feline blood transfusions: Though rare, a cat can become infected with CSD if given a feline blood transfusion from an infected cat.

As its name suggests, humans most commonly contract cat scratch fever from cat scratches or bites. You can also contract it if an infected cat licks your broken skin or an open wound.

Risk factors

There are a few factors that can put humans at a greater risk for cat scratch fever. Of course, the more exposure a person has to cats, the greater their risk of contracting the disease, especially if they spend a lot of time with kittens who tend to be more rambunctious and playful. Their risk increases even more if those cats have fleas, as fleas are the primary source of the disease.

If a person is bitten or scratched by a cat, it’s a good idea to clean those scratches with soap and water immediately. It’s also best to prevent cats from licking open wounds. Those with weakened immune systems should keep a close eye out for symptoms of cat scratch fever (see more below). Complications of the infection may include a skin and internal organ disorder known as Bacillary angiomatosis or a pink-eye-like condition known as Parinaud’s oculoglandular syndrome.²

Symptoms of Cat Scratch Fever

Cat scratch disease can be passed from cat to human, but its presentation is very different between the two.

Symptoms in Cats

Cats who are infected with cat scratch disease rarely show any symptoms or get ill from the bacteria. They are simply carriers of the disease. In very rare cases, a cat infected with Bartonella may experience:

• A fever lasting 3 or more days
• Vomiting or decreased appetite
• Lethargy
• Red eyes
• Swollen lymph nodes³

Symptoms in Humans

Once passed to humans, cat scratch fever symptoms may include:

• Red or swollen cat scratches or bites that either don’t heal or progressively become worse
• Swollen or painful glands in the armpits or groin
• Flu-like symptoms like fever, fatigue and sore joints
• A pus-filled scab or blister near the scratch or bite⁴

Diagnosing & Treating Cat Scratch Fever

While cat scratch fever has little impact on cats, it can have a much stronger effect on humans. Let’s review the differences between diagnosis and treatment in each group.

Diagnosis and Treatment in Cats

Because cat scratch fever is nearly imperceptible and has little to no effect on cats, they are rarely tested for the disease, unless they have had a known exposure or are showing signs of illness. In the rare case that a cat is donating blood, they may be tested as a precaution.

Typically, a cat that is positive for Bartonella henselae doesn’t require any treatment. It’s simply a matter of waiting for their immune system to get rid of the disease on its own. A veterinarian may prescribe antibiotics if a cat becomes ill due to the disease or if the cat has a lot of exposure to a human with a compromised immune system. However, the efficacy of antibiotics in treating cat scratch fever is iffy, as the bacteria is often antibiotic-resistant.

Diagnosis and Treatment in Humans

Because humans have a much more significant reaction to cat scratch disease, there are more methods for both diagnosing and treating it. If you or a loved one have recently been scratched or bitten by a car and begin to show signs of the disease, it’s a good idea to see a doctor. They can diagnose you based on a physical exam and blood test.

Treatment for cat scratch fever may vary based on a person’s age, overall health, and the severity of the disease. In most cases, no treatment is required. However, a doctor may prescribe an antibiotic to help fight the infection.

Cat Scratch Disease Prevention

Preventing cat scratch fever begins with protecting your cat. Implement the following to minimize both your and your cat’s risk of contracting cat scratch fever:

• Routine flea and tick prevention: The first step in protecting your cat from cat scratch fever is to implement a good flea prevention routine. Talk to your vet about the best flea and tick prevention medication for your cat’s needs and use it according to package instructions.
• Treat fleas: If your cat begins to show signs of fleas like chronic itching and hair loss, or you find flea dirt in your home, treat your cat for fleas as soon as possible.
• Keep your cat indoors: While indoor cats can still carry disease, limiting their exposure to other cats can reduce their exposure to the disease. Remember that keeping your cat indoors is not a replacement for flea prevention—indoor cats may still be exposed to fleas.
• Avoid cat scratches, bites, and licks: This is especially important when interacting with kittens or stray cats, or if you have a compromised immune system.
• Clean cat bites or scratches immediately: In fact, it’s generally a good idea to wash your hands after touching cats.
• Seek medical attention if injured by a cat: If you do experience a cat bite or scratch that breaks the skin, consult your physician for next steps.

FAQs

How do you know if you have cat scratch fever?

If you were recently bitten or scratched by a cat and the wound appears red, swollen, or raised, you may have been exposed to cat scratch fever. Keep an eye out for sore or swollen glands and flu-like symptoms, and watch to see if a pustule appears at the site of the wound. If you discover any of these symptoms, it may be time to talk to your doctor.

Is cat scratch fever an emergency?

Your immune system may be able to deal with cat scratch fever on its own. If you’re worried that you may have cat scratch fever, or if your symptoms are acute, you may want to speak with your doctor about severity and treatment.

Should I be worried if a cat scratches me?

Cat scratches themselves may not be a cause for concern, but it’s a good idea to treat them immediately. Simply washing with soap and water can be a good first step in protection. It’s also a good idea to keep an eye out for any symptoms of cat scratch fever and act accordingly.

Does cat scratch fever go away on its own?

Your immune system may be able to fight cat scratch fever by itself. Talk to your doctor about whether you have any underlying risk factors or if your infection may need more serious treatment.

Final Notes

Cat scratch disease may not be a serious concern for your cat—but it may have a significant effect on your health if you are exposed. If your cat doesn’t have a flea and tick prevention routine, talk to one of our vets about implementing one today.

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