A cat scratch, even a minor one, can introduce bacteria into the skin, making immediate and proper care necessary to prevent infection. Cats naturally carry various microbes on their claws and in their saliva that can lead to localized problems or, in rare cases, systemic illness. This guide details the practical steps you should take immediately following the injury and explains how to monitor the wound for complications. Knowing when to seek professional medical help can significantly reduce the potential for serious health issues.
Immediate First Aid for Cat Scratches
The moment skin is broken, the primary goal is to flush out as much foreign material and bacteria as possible. Start by washing your hands thoroughly with soap and water to prevent introducing new contaminants to the wound site. Then, place the scratched area under gently running tap water and clean it with a mild soap.
Gently clean the wound for several minutes to ensure thorough flushing, being careful not to scrub the area, which could cause further tissue damage or push bacteria deeper. Avoid using harsh antiseptics like hydrogen peroxide or rubbing alcohol, as these can irritate the tissue and slow the healing process. Once the wound is cleaned, use a clean cloth or sterile gauze to pat the area dry.
If the scratch is bleeding, apply light, steady pressure using a clean cloth or sterile dressing until the flow stops. After the bleeding is controlled and the wound is dry, apply a thin layer of an over-the-counter antibiotic ointment. Products containing bacitracin, neomycin, or polymyxin B are commonly used to inhibit bacterial growth and reduce the risk of infection.
Covering the wound with a sterile adhesive bandage is advisable, especially for deeper or larger scratches, to keep the area clean and protected from environmental dirt. For minor, superficial abrasions, a bandage may not be necessary once the wound is dry and treated with ointment. Change the dressing at least once daily, or immediately if it becomes wet or visibly dirty, to maintain a clean healing environment.
Monitoring for Localized Infection and Seeking Medical Attention
Following first aid, monitor the scratch closely for signs of a localized bacterial infection, which typically manifests within 24 to 48 hours. Signs that the wound is becoming infected include increasing redness, swelling, and warmth around the site. Pain that begins to worsen after the initial day of injury, rather than improving, is a common indicator that a bacterial colony is establishing itself.
The presence of pus or any yellowish or greenish drainage from the wound is a clear sign of infection and warrants professional medical evaluation. Watch for red streaks extending away from the scratch toward the heart, which can indicate a spreading infection of the lymphatic vessels, known as lymphangitis. Any fever accompanying these localized symptoms is also a cause for concern.
Prompt medical attention is necessary if the scratch is a deep puncture wound, especially if it is located near a joint or on the face. These wounds can inject bacteria deep into the tissue, where the body’s defenses struggle to reach. Individuals with compromised immune systems, such as those with diabetes or HIV, should seek care immediately, as they have a significantly higher risk of severe infection.
If the scratch was caused by a stray or feral cat, or if your cat is not vaccinated, consult a healthcare provider. The tetanus vaccination status should also be reviewed. If more than five years have passed since your last booster, a new tetanus-toxoid containing vaccine may be recommended, particularly if the wound is contaminated or deep.
Specific Health Risks Associated with Cat Scratches
Beyond common bacterial infections, the most specific systemic risk associated with a cat scratch is Cat Scratch Disease (CSD), sometimes called cat scratch fever. This illness is caused by the bacterium Bartonella henselae, which is carried by cats, especially kittens, exposed to fleas. The bacteria are often found in the feces of infected cat fleas, which contaminates the cat’s claws as it grooms.
Transmission occurs when the cat scratches, introducing the bacteria-laden flea dirt into the broken skin. A small, non-healing papule or pustule may appear at the scratch site a few days to a week after the injury, though this initial lesion is often minor and overlooked. The most characteristic symptom of CSD is the delayed onset of swollen lymph nodes.
These enlarged, tender lymph nodes often develop one to three weeks after the scratch, typically in the region closest to the injury, such as the armpit or groin. The swelling can be pronounced and may be accompanied by systemic symptoms like a low-grade fever, headache, or fatigue. While CSD is usually a self-limiting illness that resolves on its own, it can cause more serious complications in rare instances.
A deep scratch that penetrates the skin layers could potentially introduce the Clostridium tetani bacteria, which causes tetanus. Maintaining an up-to-date tetanus vaccination is the best preventive measure against this rare but serious risk.