Reviewed by Dr. Fiona Lee
Cat scratch fever, which is also known as cat scratch disease (CSD) or Bartonella henselae infection, is a disease that can affect both cats and humans. While it may sound harmless, this condition can have serious consequences if left untreated. Read on to discover the causes, symptoms, prevention and treatment of cat scratch fever.
What is cat scratch fever?
Cat scratch fever, a term coined from the primary mode of transmission to people, typically occurs when a cat scratches or bites a human. It is caused by the bacterium Bartonella henselae (B. henselae), which is carried in the cat's saliva and comes from fleas.1 The bacteria can be transmitted to humans through cat scratches, bites or contact with contaminated cat saliva.
What causes cat scratch fever?
Bartonella henselae bacteria can enter a person's bloodstream through open wounds or mucous membranes. Transmission usually occurs through cat bites or scratches that are contaminated with flea feces containing the organism. Note that not all cats carry this bacterium, and many infected cats show no symptoms.
Cat scratch fever is a zoonotic disease, which means it can be transmitted from animals to humans. Preventing the disease in our feline companions is important for both pet and owner health.
Symptoms and signs of cat scratch fever
While cats may carry Bartonella henselae without showing any symptoms, on rare occasions it can cause serious inflammation of the heart, which can be very dangerous.2
Humans who contract the disease from their cat usually show more obvious symptoms three to 10 days after a cat scratch or bite. Symptoms may include:3
- Lethargy
- Fever
- Muscle, bone or joint aches
- Swollen lymph nodes
- Loss of appetite or weight loss
- Skin lesions or bumps that look like a rash at the site of the bite or scratch
If your cat is lacking energy, just doesn't seem themselves or is behaving in unusual ways, speak with your veterinarian to get expert advice on the next steps.
Recognizing cat scratch fever
Recognizing Bartonella henselae symptoms in cats can be difficult, as they often display mild or no signs of the disease. Regular veterinary checkups are essential to detect and treat potential infections. Flea control is important as well.
Since cat scratch fever may not always be visually apparent in cats, it can be challenging to detect solely by appearance. It's more likely that human symptoms will be detected first and then lead back to a diagnosis of cat scratch fever in the cat as well as the person.
How to diagnose cat scratch fever
If you suspect cat scratch fever in your cat, yourself or others you live with, consult a doctor and a veterinarian to get the right care for every member of your family.
If you experience any symptoms, particularly after a cat scratch or bite, visit your healthcare provider immediately.
Veterinarians may perform physical examinations, use polymerase chain reaction (PCR) tests or take blood or tissue cultures to detect an active infection. However, cat scratch fever can be difficult to diagnose in cats. Since cats rarely show signs of the disease, it's more likely that an infected person would be diagnosed by their doctor rather than a cat being diagnosed by their veterinarian.
Cat scratch fever treatment options
Cat scratch fever is usually considered mild and self-limited, which means patients (both human and feline) are often not prescribed medication or further treatment, as the body's immune system will fight off the infection.4 However, in some cases, the following treatment options may be advised.
Antibiotics
In both cats and humans, antibiotics can be prescribed if the patient is not recovering well by themselves.
Supportive care for symptomatic relief
Supportive care, including rest, hydration and pain management, can help alleviate any symptoms and aid recovery. These holistic options are beneficial for a range of common health conditions in your pet.
Hospitalization in severe cases
In severe cases—usually in people who are immunocompromised with an underlying disease—it may be harder to treat cat scratch fever. Hospitalization may be necessary, especially if there are complications.
Progress monitoring and follow-up visits
Regular follow-up visits with a veterinarian and your medical provider are essential to monitor progress and ensure a full recovery for all infected parties.
Preventing cat scratch fever
There are currently no vaccinations available for cats against Bartonella henselae, so preventive steps are the best bet to avoid the disease.5
Even those who are immunocompromised or living with a serious disease do not have to live without their kitty to stay protected from cat scratch fever.6 The following precautions can keep you both safe and well.
Keep your cat indoors
Limit your cat's exposure to fleas by keeping them indoors and treating them with a flea control product recommended by your veterinarian to reduce the risk of Bartonella henselae transmission.
Avoid cat scratches, bites and licks
Be mindful of how you interact with your cat to avoid bites and scratches. Practice proper cat discipline to teach your kitty appropriate ways to play. Be sure to promptly wash any cat scratches or bites with soap and water.
Ensure regular grooming and nail trimming
Keeping your cat's nails trimmed and practicing good hygiene can help minimize the risk of scratches without resorting to painful and unnecessary options like cat declawing.
Pets Best is here to help
Responsible pet ownership includes taking all reasonable measures to keep your pet happy and healthy, including securing comprehensive cat insurance plans for peace of mind when your cat is feeling under the weather. Your policy at Pets Best also comes with access to a 24/7 Pet Helpline for all your pet health-related questions.
By recognizing the causes and symptoms of cat scratch fever and the preventive steps needed, you can ensure a safer and healthier environment for yourself and your feline companion. When in doubt, always seek veterinary advice to keep yourself and your beloved cat in good health.
Sources/Citations
1. “Cat Scratch Disease," (11/2019), John Hopkins Medicine, https://www.hopkinsmedicine.org/health/conditions-and-diseases/cat-scratch-disease, accessed September 28, 2023.
2. “Cat Scratch Disease," (6/2023), Centers for Disease Control and Prevention, https://www.cdc.gov/healthypets/diseases/cat-scratch.html, accessed September 28, 2023.
3. “Cat Scratch Fever," (7/2022), Cleveland Clinic, https://my.clevelandclinic.org/health/diseases/23537-cat-scratch-fever, accessed September 28, 2023.
4. “Cat-scratch Disease," S.A. Klotz (1/2011), American Academy of Family Physicians, https://www.aafp.org/pubs/afp/issues/2011/0115/p152.html, accessed September 28, 2023.
5. “For Veterinarians," (1/2020), Centers for Disease Control and Prevention, https://www.cdc.gov/bartonella/veterinarians/index.html#, accessed September 28, 2023.
6. “Bartonella henselae or cat scratch disease (CSD) FAQs," (1/2022), Centers for Disease Control and Prevention, https://www.cdc.gov/bartonella/bartonella-henselae/faq.html#, accessed September 28, 2023.