A recently published case reported last week in the journal BMJ Case Reports, describes the rare, yet very serious infection that can be contracted by “man’s best friend”.


The case out of the United Kingdom is summarized as follows:

A 70-year-old Caucasian woman was treated for Capnocytophaga canimorsus septicaemia. The source of bacteraemia was very likely to be her household pet, an Italian greyhound. The patient presented with a presumed complex partial seizure but deteriorated rapidly with sepsis and multiorgan dysfunction. Neither scratch nor bite was established, although close petting including licks was reported. Blood cultures grew Gram-negative rods, identified by molecular techniques as C. canimorsus—a bacterium frequently isolated in the oral cavities of dogs and cats. A full recovery was made following 2 weeks of intensive care support and broad-spectrum antibiotics. No underlying immune dysfunction was found.

What is Capnocytophaga canimorsus?

The bacterium, Capnocytophaga canimorsus is a relatively new reported pathogen (the first case reported about 30 years ago). It has been isolated from the saliva of healthy dogs and cats. It is typically transmitted via a dog bite; however, transmission has been reported from licks.

It is for the most part considered an opportunistic pathogen, causing little problems with healthy individuals, usually causing the most severe disease in those with a predisposing condition; splenectomy, chronic alcohol abuse, or immune system problems (steroid therapy, blood malignancies and AIDS).

Related: Infections you can get from domestic cats

Splenectomized individuals are 30 to 200 times more prone to die from bacterial infections because the spleen produces cells that become antibody-producing cells. Also the spleen is integral is sending out macrophages (cells that engulf and destroy foreign substances like bacteria in the bloodstream).

The clinical illness is typically one of severe septicemia, shock and disseminated intravascular coagulation. Other manifestations of the disease include cellulitis, gangrene, meningitis and brain abscesses. The infection with Capnocytophaga carries a 27% chance of being fatal.

It is treatable with antibiotics.

The authors of the case report note that 13 cases have been reported in the UK since 1990.