Cat Scratch Disease: Causes, Symptoms and Prevention

Cat scratch disease is an abbreviation of CSD. It is also known as ‘Cat Scratch Fever’and ‘Subacute Regional Lymph’ (its medical name). The name Cat Scratch Disease suggests that a cat bite or a cat scratch can transmit disease-causing bacteria, Bartonella Henselae in a human body. The Center of Diseases Control and Prevention (CDC) has estimated that around 12k people will be diagnosed with Subacute Regional Lymph. Also, around 500 people will be under medical observation in hospitals each year in the United States.


Causes of Cat Scratch Disease

cat scratch fever disease

This disease can be caused by the bite or the scratch of the cat infected with B Henselae bacteria. The contact of saliva of infected cats with your white eyes or your open wounds can also cause CSD. However, most of the cats may carry these bacterias but may not have the disease. We can observe this disease in the kids of the age group of 5-9 years. Some people may get CSD by flea or tick bites carrying the bacteria. Domestic cats are most prevalent to cause this disease.


in Cats

According to CDC,  around 40 percent of cats in their whole lifespan carries the B Henselae bacteria and most probably when they are kittens. As discussed, cats do not develop this disease even though they carry disease-causing bacterias. So, Vets do not usually recommend CSD test for your kitty. Cats get this bacteria from B Henselae infected fleas. Rarely, humans are a cause of this CSD in cats too.

in Humans

The first sign of Cat Scratch Fever is a bump or blister on the inoculation site after a cat’s scratch or bite. This bacterial infection affects lymph nodes and drains the site of inoculation. Initially, a papule is formed on the scratch area. This papule generally develops on arms, head, and scalps. Most of the times, these papules are not painful.

After, 2-3 weeks, lymph nodes in the vicinity of the papule or inoculation site will start swelling. For instance, Despite inoculation site is on the leg, you can observe swollen lymph in the groin. These nodes are of the size of 1/2 – 2-inch diameter. As time progresses, it may get red and tender as time progresses. In 2-4 months’ time, the symptoms start getting eased up and vanishes completely.

Below are some symptoms that are accompanied by skin complications.

  • Fatigue
  • A headache
  • Mild fever that ranges between 98.6°F – 100.4°F temperature
  • Body ache


You cannot just observe the symptoms and diagnose Cat Scratch Disease as these symptoms can be common for other diseases. If your doctor believes you might be carrying this disease, then he would run a medical test called Bartonella Henselae immunofluorescence assay (IFA) blood test. This test is most accurate to check whether you have B Henselae bacteria or not.


There are some rare complications which CSD can cause. Let your doctor know about your cat scratch disease to avoid rare but fatal complications.

Parinaud Oculoglandular Syndrom

Parinaud Oculoglandular Syndrome is an eye disease which has similar characteristics as of unilateral granulomatous follicular conjunctivitis. You can develop this syndrome due to the direct contact of your eye whites with your cat. And also, it can develop due to the B Henselae transmitted to your eyes by the bloodstream. Usually, this complication responds well to antibiotics.


Osteomyelitis is a very rare but serious complication caused by Staphylococcus aureus, a kind of staph bacteria. These bacteria can develop a bone infection during cat scratch fever and in severe cases. It may cause an amputation. This infection can develop in any part of the bones of your body as the bacteria causing this disease flows with the bloodstream.


Neurorentinitis is another eye disease which associates inflammation of optic nerve and retina. 77% of people diagnosed with cat scratch disease shows systematic symptoms such as inflammation and blurred vision. Only 7.7 percent of them manifest eye pain.


Encephalopathy is a general term for brain-related symptoms. This complication occurs when the bacteria reach your brain. The common symptoms are altered mental state, brain damage and brain malfunction.


A simple step to prevent this disease is to avoid direct contact with your cat. This looks nearly impossible as you love your feline furball, right? You can avoid the rough play with your furball friend which mitigates the risk of it biting or scratching you. Always trim its nails in order to make them less sharp and harmful.

Do not let your pet to touch or lick in the vicinity of eyes, mouth and the wounds. Cover your wounds with a waterproof bandage while in contact with the cat. Make sure you clean your hands and other body parts which were in contact with your cat before eating.

You should administer an anti-flea medication for your kitty and keep it indoors. You can always check your kitten’s fur if there are any fleas or not by using a comb. A pest control agency can make your home flea free, and you and your kittens will be safe from CSD.

If you are an HIV positive or a cancer patient then immediate steps are crucial as this disease makes your health the worst. Adopt an adult cat instead of adopting a kitten as they are the most vulnerable to B Henselae bacteria.

People diagnosed with this disease generally get better spontaneously over the course of time.

However, People seeking medical attention will get healthy soon using suitable antibiotics. Moreover, you need to consult your doctor as soon as you discover the first signs to avoid rare but serious complications like Encephalopathy, Nurorentenitis, and Osteomyelitis.

1 thought on “Cat Scratch Disease: Causes, Symptoms and Prevention”

  1. My husband’s cousin was scratched by a cat and was infected with cat scratch fever. This was before we met; and to be honest, embarrassingly, I thought “cat scratch fever” was just a song. However; it is terrifyingly serious! She had years of problems before I met her; and by the time I did; she honestly had part of her brain removed to ease some of whatever was going on. (I know she was suffering seizures, but not sure what else.) She cannot drive to this day, and she talks very deliberate and slow. It’s no light thing; and I vowed to NEVER have a cat. I live in the country and now have 8 that I care for. But it’s always on my mind; and with children; I wish I wasn’t such a softy!!!


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