Introduction
Cat scratches are very common injuries, especially among cat owners. A cat scratch occurs when a cat’s claws puncture or scrape the skin, often leaving behind red lines or marks on the skin’s surface. While most cat scratches are minor and heal on their own, they can sometimes lead to more serious complications like infections. This article provides an overview of the potential risks of cat scratches and what to do if you get scratched.
Potential Risks
Cat scratches can potentially transmit diseases to humans in some cases. The main risks from cat scratches are bacterial infections, cat scratch disease, and rabies. However, these risks are generally quite low for domestic cats who are appropriately vaccinated.
Bacterial infections from cat scratches are typically caused by Pasteurella multocida bacteria which live in a cat’s mouth and claws. According to the CDC, these bacteria can be transmitted through a bite or scratch and cause infection at the wound site or other more serious infections in people with weakened immune systems [1].
Cat scratch disease is caused by a bacterium called Bartonella henselae. This bacteria can be passed from cats to humans through bites, scratches, or by coming into contact with cat saliva. According to Johns Hopkins Medicine, cat scratch disease often causes swollen lymph nodes near the scratch or bite site along with fever or fatigue [2]. While typically mild, rare complications can sometimes occur.
Contracting rabies from a cat scratch is very rare, but could potentially occur if a cat was infected with rabies. The CDC notes that the rabies virus is transmitted through saliva or brain/nervous system tissue, most often through bites. However, scratches may also transmit rabies if saliva enters the wound [1].
Bacterial Infections
Cats commonly have bacteria under their nails that can enter a wound when scratching humans, leading to potential bacterial infections. The most notable bacteria is Bartonella henselae, which causes a disease in humans called cat scratch disease (CSD) or cat scratch fever. As stated in an article published by Cornell University, CSD occurs when the Bartonella bacteria “migrate from a cat scratch or bite into the skin and cause infection in the person bitten or scratched” (Cornell). CSD typically causes swollen lymph nodes and fever in humans within 3-14 days after a cat scratch.
According to a research study published in the CDC journal Emerging Infectious Diseases, the average annual incidence of CSD in the United States is approximately 4.7 cases per 100,000 people under age 65 (Nelson, 2016). While CSD usually resolves on its own, antibiotics are sometimes given in more severe cases. Overall, cat scratches can potentially lead to bacterial infections, with CSD being the most common.
Cat Scratch Disease
Cat scratch disease (CSD) is caused by a bacterium called Bartonella henselae. This bacteria is carried in the saliva of infected cats and can be transmitted through a bite or scratch. According to the CDC, there are around 12,000 cases of CSD reported each year in the United States, though many mild cases likely go undiagnosed [1].
The most common symptoms of cat scratch disease include[1]:
- A red bump or mild infection at the scratch site that appears 3-14 days after the injury
- Swollen lymph nodes near the scratch/bite location
- Fever
- Headache
- Fatigue
- Poor appetite
In most people, symptoms resolve on their own within a few weeks. However, in rare cases, the infection can spread to other parts of the body and cause more serious complications like encephalitis, endocarditis, or osteomyelitis.[1]
Rabies
Rabies is an extremely rare consequence of a cat scratch. Rabies is caused by a virus that attacks the nervous system and is spread through saliva, usually from a bite. While any mammal can carry rabies, it is typically found in wild animals like bats, raccoons, skunks and foxes. Domestic cats can contract the virus if they come into contact with an infected wild animal. However, rabies is rare in pet cats who live exclusively indoors.
The rabies virus is very rarely transmitted from a scratch. This is because the scratch usually does not break the skin deep enough to introduce saliva carrying the virus. Bites are much more likely to transmit rabies. According to the CDC, of the 55,000 people who receive rabies preventive shots annually, only 1-3 cases of rabies from cats are reported.
If rabies is transmitted via a cat scratch, symptoms typically appear within 1-3 months. Early symptoms include fever, headache and general weakness. As the disease progresses, more serious symptoms emerge including hallucinations, agitation and insomnia. Once clinical symptoms appear, rabies has a mortality rate near 100%. However, rabies can be prevented if treatment is administered promptly after exposure.
People at Higher Risk
Certain groups of people are at higher risk for developing serious complications from cat scratches, according to the Centers for Disease Control and Prevention (https://www.cdc.gov/healthypets/diseases/cat-scratch.html).
Young children are more susceptible because their immune systems are still developing. The elderly also have weakened immune systems, making them more vulnerable to infections from cat scratches.
However, those at highest risk are people with compromised immune systems, such as those with HIV/AIDS, those on chemotherapy, transplant recipients, and people on steroids. These immunocompromised individuals are much more likely to develop systemic illness and serious complications from cat scratch disease.
According to a study from Cornell University (https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/cat-health-news/cat-scratch-disease-are-you-risk), immunocompromised individuals are at a higher risk for serious complications of cat scratch disease, which can include encephalitis, neuroretinitis, and osteomyelitis. It’s critical for these high-risk groups to take precautions against cat scratches and promptly treat any scratches that do occur.
Prevention
There are several things cat owners can do to help prevent scratches from their feline companions.
It’s important to regularly trim your cat’s nails. Keeping their nails short and smooth will reduce the chance they can cause deep scratches if they do swipe at you. Use cat-safe nail clippers and trim only the sharp tip of the nail, being careful not to cut too close to the quick or it may bleed and be painful for the cat.
Avoid playing rough or antagonizing your cat. Games like wrestling with your hands or feet may look playful but can rile up your cat too much. This can lead to accidental scratches. Instead, use toys on strings or fishing pole type toys to keep a safe distance during play.
When petting or handling your cat, move slowly and gently. Avoid petting near sensitive areas like the stomach unless your cat is very comfortable with it. Sudden loud noises or rough handling can startle cats and cause them to scratch defensively. Always approach cats calmly from the front so they see you coming.
With some basic precautions, cat owners can often avoid scratches even from the feistiest feline.
Treating Scratches
For minor scratches, the most important step is to clean the wound thoroughly. Use running water and mild soap to gently wash away any dirt or bacteria from the scratch. Avoid vigorously scrubbing the wound, as this can cause more irritation. After cleaning, pat the area dry with a clean towel (PetMD).
Antibiotic ointments like Neosporin can help prevent infection by keeping the wound moist and protected. Apply a thin layer of ointment and cover with a bandage if needed. Keep the scratch clean and watch for signs of infection like redness, swelling, oozing pus, or fever (Preventive Vet).
While most minor scratches can be treated at home, seek medical care if the wound is deep, won’t stop bleeding, or shows signs of infection. Puncture wounds and scratches on the face or joints warrant extra caution, as they have higher risks of complications. Contact your doctor right away if you experience blurred vision, swollen lymph nodes, or flu-like symptoms after a cat scratch, as these may indicate a serious infection. Getting prompt medical attention can help prevent dangerous illness from a cat scratch (Preventive Vet).
When to See a Doctor
Cat scratches can sometimes lead to infection or disease, even if the scratch seems minor. Contact your doctor if you experience any signs of infection, which include:
- Redness, swelling, pus, or oozing around the scratch
- Red streaks leading from the scratch
- Fever, chills, or fatigue
- Lymph node swelling near the scratch
- Worsening pain or discomfort
You should also see your doctor if you develop symptoms of cat scratch disease, such as headache, joint pain, and poor appetite within 3-14 days after a cat scratch. This bacterial infection is transmitted through cat scratches and bites.
People with weakened immune systems, such as those with HIV/AIDS, cancer, or organ transplants, are at higher risk of complications from cat scratches. Seek medical care promptly if scratched.
Children are also more prone to infection from cat scratches. Contact your pediatrician if your child has a cat scratch that becomes swollen, red, or tender.
Conclusion
In summary, while cat scratches are generally low risk, they do have the potential to cause harmful infections in some cases. Cat scratch disease, caused by bacterial infection, can lead to swollen lymph nodes and fever. More serious but rare risks include contracting rabies or infection that spreads to joints or the bloodstream. Scratches are of greatest concern for those with weakened immune systems, such as the elderly, infants, or those undergoing chemotherapy.
Still, these dangers can be minimized by taking proper precautions. Carefully washing and disinfecting any scratch right away reduces infection risk. Keeping cats’ nails trimmed and watching for signs of infection can also help prevent problems. Seeking prompt medical attention for any signs of infection or illness following a scratch is advised. With vigilance and care, cat scratches can usually be managed safely.