Pet cat bites are common—the most typical patient being a child, and the most typical locality hands and face. The normal flora of a pet cat’s mouth houses very potent pathogens. Therapeutic measures include wound cleansing, prophylaxis against tetanus and possibly rabies. Antibiotic prophylaxis should be administered in the cases of all but the mildest superficial wounds especially if the wound is in the hand or face. We present a review on the medical care of cat bite wounds and a typical case of a patient who developed rapid symptoms and signs of infection after a pet cat bite and nearly required hospitalization. The clinical picture was consistent with a Pasteurella infection.
Up to 90% of animal bites are caused by dogs and cats [
The patient was a 59-year-old immunocompetent female. She was bitten on her left thenar by a pet cat, and presented with two small puncture wounds. The patient administered satisfactory first aid cleansing and dressing of the wounds. Within four hours the hand became swollen, painful and warm. Medical attention was sought and oral amoxicillin-clavulanic acid 875/125 mg twice daily was instituted. In addition, a tetanus booster shot was given. On the following day her temperature was mildly elevated and the lymph nodes in her left armpit were swollen. On the second day after the bite general malaise and mild fever had subsided but a red line indicating lymphangitis was developing in the upper limb. The limb was observed carefully, and since the patient was feeling better, oral antibiotics and local treatment were continued. Signs of lymphangitis ameloriated in 3 - 4 days after which the patient was feeling good. The puncture wounds produced pus from day 2 to approximately day 4. The patients required a sick leave of one week, and the antibiotics were continued for 10 days altogether.
The fact that cat bite wounds get infected more frequently (up to 50% - 80% of cases) than do dog bite wounds (no more than 20% of cases) is probably related to sharper teeth of cats leading to deeper inoculation of bacteria and subsequent soft tissue abscesses or septic arthritis [
Animal bite wound infections frequently are polymicrobial—up to 56% of infections are caused by a mix of aerobic and anaerobic bacteria [
Local first aid of the wound by washing with clean water is of utmost importance. An open or jagged wound should be rinsed with saline using a large bore needle and syringe, although cat bites tend to have a small entry of wounds making this kind of cleansing impractical. Suturation of bite wounds is generally not recommended. In aesthetically critical areas such as the face, can it be cosmetically prudent sometimes to close the bite wound despite the fact that it increases the risk of deep infection.
Our patient was treated with antibiotics only after signs and symptoms of infection. However, it should be stressed that a proper strategy would have been to treat her with a 5-day course of prophylactic amoxicillin-clavulanic acid immediately after the bite. In fact, it is logical that prophylactic antibiotics improve the outcome after cat bites when majority of deeper puncture wounds lead to infection without it. However, patients might not seek medical attention until symptoms are already evident.
Antibiotic treatment of cat bites is recommended in all but the mildest surface injuries. Although majority of Pasteurellas are sensitive to amoxicillin is amoxicillin-clavulanic acid the preferred choice because of the frequency of mixed infections including anaerobic bacteria. The use of prophylactic antibiotics in mammalian bites was studied in a Cochrane review in 2001 and in an update in 2008 [
Lymphangitis is not always a symptom of progressing bacterial infection—it may also be an inflammatory reaction. In our case it likely was due to bacterial infiltration, but the overall well-being of the patient allowed a decision to continue with oral antibiotic treatment. Progressive lymphangitis that is suspected to be the result of rising bacterial infection generally indicates the need for hospitalization and intravenous treatment. In the absence of clearance of local signs a suspicion of abscess formation raises and surgical treatment should be considered.
We conclude that the normal flora of a pet cat’s mouth houses very potent pathogens. Antibiotics should be administered in all but the mildest injuries regardless of whether there already are symptoms of infection. Our patient nearly required hospitalization after getting two very small puncture wounds on her left thenar.
J.O.: Lectures, congress travel, consultations (Abbott/AbbVie, Astellas, Baxter, Bristol-Myers Squibb, Gilead Sciences Finland, GlaxoSmithKline, MSD Finland, Pfizer, Ratiopharm, Tibotec/Janssen). Others: no conflicts of interest.