Primary Care in Rochester and Kasson

When kitty turns tiger, take it seriously

12/30/2021 by Denise Dupras, M.D., Ph.D.


Just beneath the coat of your Kitty lies a tiger waiting to pounce. House cats are biologically designed to be efficient hunters and complete with the tools they need — sharp claws and teeth for grabbing and killing prey. Unfortunately, sometimes that "prey" is their human's hands, face or feet. 

It doesn't take much for Kitty to turn tiger. A game that gets out of hand or being overexcited, frightened by another animal or startled by a noise can trigger their predator response, and the claws come out. (Even declawed cats usually still have a full set of back claws in working order.) If you're a victim of a cat bite or scratch, take is seriously to avoid becoming infected with cat-scratch disease (CSD). 

What is CSD?

It's an infection caused by being bitten, scratched or having an open wound licked by a cat carrying a bacterium called Bartonella henselae. About 40% of cats carry this bacterium at some time in their lives, although most never show signs of illness. Kittens younger than one year are more likely to be infected and spread the germ, since they often bite and scratch as they play and learn how to attack prey. 

How do cats get infected?

Cats can pick up the bacterium from flea bites and getting flea droppings into their wounds. They also can become infected by fighting with other cats that are infected. 

How do you know if you have CSD?

About 3 to 14 days after the bite or scratch, a mild infection can set in. The affected area may look swollen and red with round, raised lesions and possibly, pus. It also may feel warm or painful. The infected person may have a fever, headache, poor appetite and be excessively tired. As the infection progresses, lymph nodes closest to the original scratch or bite can become swollen, tender or painful. 

Although rare, CSD can cause serious complications, affecting the brain, eyes, heart or other internal organs. These rare complications, which may require intensive treatment, are more likely to occur in children younger than 5 years old and people with weakened immune systems. 

How is CSD treated?

Wash bites and scratches well with soap and running water. Keep an eye on the wounds and contact your care team if you develop any symptoms of infection. You may need to be treated with antibiotics. 

How can it be prevented?

Protect your cat by keeping it indoors and make sure it has regular veterinary care. But as every cat owner knows, scratches and nips happen. That's why it's important for everyone to learn how to play safely with them, such as using toys for "prey" rather than your hands, holding them correctly and realizing that your Kitty has the heart of a tiger. 

Denise Dupras, M.D., Ph.D., is a general internist in Community Internal Medicine, Geriatrics and Palliative Care at Mayo Clinic in Rochester. She completed her medical and doctoral degrees at Mayo Clinic Alix School of Medicine and her residency in internal medicine at Mayo Clinic in Rochester. Her interests include medical education, evidence-based medicine and care of LGBTQIA+ patients.