If a cat just bit you, wash the wound thoroughly with soap and running water for at least five minutes, then seek medical attention. Cat bites carry a surprisingly high infection rate, somewhere between 20% and 80%, compared to just 3% to 18% for dog bites. Even a small puncture that looks harmless on the surface can push bacteria deep into your tissue, so treating every cat bite seriously from the start is the single most important thing you can do.
Why Cat Bites Are More Dangerous Than They Look
A cat’s teeth are narrow and needle-sharp. About 85% of cat bite injuries are puncture wounds rather than tears or lacerations, which means the teeth act like tiny hypodermic needles, injecting bacteria deep beneath the skin. The small entry hole then closes over quickly, trapping bacteria in an environment with limited oxygen and blood flow where they thrive.
The most common culprit is a type of bacteria that lives in the mouths of most healthy cats. Once deposited under the skin, it multiplies rapidly in the warm, sealed-off wound. This is the core reason cat bites become infected so much more often than dog bites: it’s not that cat mouths are dirtier, it’s that the shape of their teeth delivers bacteria to the perfect hiding spot.
Cat bites land on the hands and fingers 45% to 80% of the time. That’s a problem because hands are packed with tendons, joints, and thin tissue layers that offer bacteria easy pathways to spread. Bites near joints or tendons can lead to serious complications, including deep abscesses and, in rare cases, tendon damage requiring surgery.
Immediate First Aid Steps
Start by washing the wound with soap and water. Don’t just rinse it briefly. Hold the bite under gently running water and work soap into and around the wound for several minutes. The goal is to flush out as much bacteria as possible before the puncture closes over. If the wound is bleeding, let it bleed for a short time first, since the blood flow helps push bacteria outward.
After washing, apply an antiseptic if you have one, then cover the wound with a clean bandage. Avoid sealing the wound tightly with butterfly bandages or adhesive strips. You want some air circulation, not a sealed pocket. Once the wound is clean and covered, your next step is getting to a doctor, ideally within a few hours.
When You Need Medical Care
The short answer: almost always. Any cat bite that breaks the skin warrants a medical visit, but certain situations make it especially urgent.
- Bites on the hands, fingers, feet, or face. These areas are close to joints, tendons, and bone, giving infections a fast track to deeper structures.
- Deep puncture wounds. If you felt the teeth sink in rather than just graze the surface, bacteria are likely deep in the tissue.
- Weakened immune system. People taking immunosuppressive medications, those with diabetes, liver disease, or HIV are at significantly higher risk of severe infection. In documented cases, immunocompromised patients have developed life-threatening sepsis within days of a cat bite.
- Bite from a stray or unknown cat. This raises the question of rabies and changes how aggressively the bite needs to be managed.
A doctor will typically clean the wound more thoroughly than you can at home and prescribe a course of antibiotics lasting five to seven days. Preventive antibiotics are standard for cat bites, not just reserved for wounds that already look infected, because the infection rate is so high.
Signs of Infection to Watch For
Infection from a cat bite can develop fast. Pain, swelling, redness, and warmth around the wound can appear within just a few hours. This is unusually quick compared to most wound infections, which often take a day or two to show up. If you notice any of these signs spreading or worsening, get medical attention right away, even if you’ve already been seen once.
More advanced signs include red streaks radiating outward from the bite, pus or fluid draining from the puncture, fever, chills, or swollen lymph nodes near the wound. A wound that initially seemed to be healing but then suddenly gets worse is also a red flag. Infections that don’t respond to oral antibiotics may need intravenous treatment or, in cases where an abscess forms near a joint or tendon, surgical drainage.
Cat Scratch Disease
Separate from a standard wound infection, cat bites (and scratches) can transmit a bacterial illness called cat scratch disease. Symptoms typically begin 3 to 14 days after the bite and follow a distinctive pattern: a small pustule or blister forms at the bite site, followed one to two weeks later by swollen, tender lymph nodes near the wound. You may also develop a low fever, fatigue, headache, and poor appetite.
For most healthy people, cat scratch disease resolves on its own over a few weeks. But for people with weakened immune systems, it can become systemic, potentially causing lesions on internal organs or, in rare cases, eye infections that threaten vision. A blood test can confirm the diagnosis if your doctor suspects it based on your symptoms and exposure history.
Tetanus and Rabies Considerations
Your doctor will ask when you last had a tetanus shot. Adults need a booster every 10 years to stay protected, and a cat bite is exactly the kind of wound that puts you at risk for tetanus. If you’re overdue or unsure of your vaccination history, you’ll likely get a booster at your visit.
Rabies is rare in domestic cats in the United States, but the consequences are severe enough that it has to be considered. If the cat that bit you is a known pet with up-to-date vaccinations, rabies risk is extremely low. If it’s a stray, feral, or unvaccinated cat, public health guidelines call for a 10-day observation period. The cat is monitored (or confined) for 10 days after the bite. If it remains healthy throughout that window, it’s assumed it was not shedding rabies virus at the time of the bite, and no rabies treatment is needed.
If the cat can’t be found or observed, or if it shows signs of illness during the observation period, your doctor and local health department will discuss whether you need post-exposure rabies prophylaxis. This is a series of shots given over two weeks, and it’s nearly 100% effective when started promptly.
Bites That Need Emergency Care
Go to an emergency room rather than waiting for a regular appointment if you notice any of the following: the wound won’t stop bleeding after 15 minutes of direct pressure, you can see deep tissue or bone, you develop a fever within hours of the bite, or you see rapid swelling and redness spreading from the site. Red streaks moving up your arm or leg from the wound suggest the infection is entering your lymphatic system, and that needs urgent treatment.
Bites from cats whose rabies status is unknown also warrant an immediate visit, since rabies prophylaxis is most effective when started as soon as possible after exposure. The same goes for anyone who is immunocompromised. In these cases, the margin for waiting is much narrower than it is for a healthy person bitten by a vaccinated house cat.