Cat scratch disease is a clinical entity transmitted to humans through inoculation (scratches, stings, and bites) and characterized by skin lesions of primary inoculation site, accompanied by fever and regional adena. Etiology of this disease is still unknown, although it is believed to be caused by a microorganism belonging to the Chlamydia group, but know that it is transmitted through various contacts with infected cat. This disease is ubiquitous, yet rarely diagnosed, although most cases occur in small epidemics family (children and teenagers being the most exposed) mainly in autumn and winter.

Instead of inoculation by a cat scratch or sting occurs after 7-14 days of incubation, a red swelling, itching, which is 48 hours into a vesicle, pustule and then in 90% of cases. Soon, it is broken, leaving a small crust which eliminates a few days, but even if the primary effect is very small or absent, it is possible that, after another few days to produce swollen lymph nodes in the region injured, resulting a manifest adenopathy in 20-25% of cases, fever (38-39 degrees C), chills, headache, anorexia, nausea, abdominal pain and vomiting, accompanied by skin eruptions. Fortunately, such complications are rare, the symptoms of cat scratch disease having generally a benign, but they must avoid the appearance, logically, avoiding contact with infected cats.

Also, other problem regarding animals, it’s their bites. Cat bites are much rarer than dog bites, but very dangerous, because half of the cases recorded have led to serious and very serious infections. Poured cat teeth are very sharp, deep wound penetrate a soft tissues, thus generating an increased risk of osteomyelitis and septic arthritis (risk greater than if a dog bites). Hands are the most vulnerable areas of cat bites. Most patients with cat bites, which appear in the guard room, are female (adult or children). Usually the bites affect hands and arms in equal proportions of patients.
Bite wounds, but scratches and cat shows increased risk of infections caused by microorganisms contained in the saliva of that animal.

Most of the infections caused by cat bites are due to pathogen P. multocida, Gram-negative bacteria, the smallest, which normally colonize oropharyngeal house cats.
Generating bacteria infections occurring through cat bites, is generally mixed. A number of pathogens inoculated via cat bites are similar to those that cause infections if dog bites. Risk of infection increases considerably when the affected individual has a background that lead to pathology of the body’s depressing regarding the immune system.

Pasteurella species pathogen inoculation will lead to an outbreak inflammatory progressing rapidly (within a few hours), generating signs of severe inflammation (local pain, redness, swelling the area) and abundant purulent secretions. Pasteurella species spread pathogens from an animal carrier with aerosol drops can cause bacterium or pneumonia, human host.

Through the bite of cat, rabies or tetanus can be transmitted. Bartonella henselae bacteria inoculation will generate late appearance of "cat scratch” disease. Also, tularemia can occur after cat bites, being a symptom of cat scratch disease.