Unusually Rare, and Unfortunate

"He had been touched and licked, but not bitten or injured, by his dog, his only pet, in previous weeks."
"Pet owners with banal, for instance flu-like, symptoms should urgently seek medical advice when symptoms are unusual."
Paper produced by doctors from the Red Cross Hospital, Bremen, Germany

"[The type of bacterium, capnocytophaga canimorsus, is] completely normal flora of a dog's mouth and usually doesn't cause any sort of significant disease."
"However, in the wrong place, at the wrong time, in the wrong patient ... it can lead to severe infections -- but very, very rarely."
Dr. Stephen Cole, lecturer, veterinary microbiology, University of Pennsylvania School of Veterinary Medicine

Many studies show the health benefits of dog ownership. Dogs not only provide comfort and companionship, but several studies have found that dogs decrease stress and promote relaxation. Dogs have positive impacts on nearly all life stages. They influence social, emotional, and cognitive development in children, promote an active lifestyle, and have even been able to detect oncoming epileptic seizures or the presence of certain cancers. But for all the positive benefits of keeping dogs, pet owners should be aware that dogs can carry germs that make people sick.
Although germs from dogs rarely spread to people, they might cause a variety of illnesses, ranging from minor skin infections to serious disease. To protect yourself and your family from getting sick:

• Seek routine veterinary care for your pet and
• Always wash your hands and the hands of children with running water and soap after contact with dogs, their stool, and their food.

By providing your pet with routine veterinary care and some simple health tips, you are less likely to get sick from touching, petting, or owning dogs.
Centers for Disease Control and Prevention (CDC)

He was 63 years old, a German dog owner living in Bremen, and circumstances conspired to rob him of future years, a hugely unusual occurrence, when the man's dog transferred to him through a simple 'lick' that most dog owners interpret as a 'kiss', a common bacterium that most dogs carry. The bacterium transfer rarely results in an infection, but this time it did, on steroids. The man had severe symptoms usually associated with flu, along with laboured breathing, round skin spots like rashes from bleeding capillaries.

When he was admitted to hospital doctors found a stable heartbeat, but an internal temperature of 39C. Because of his laboured breathing an inadequate supply of oxygen reached his tissues, and his kidneys failed to produce urine. Everything about the man's presentation puzzled the doctors who suspected bacteria, but the puzzle continued with a lack of open wounds and no sign of meningitis. By his fourth  hospital day a blood test revealed the presence of bacteria commonly found in healthy dogs' saliva, transmitted most commonly through bites.

Details of the man's experience, and his rapid deterioration despite all that medical science could offer in a modern, well-equipped and highly professionally-staffed hospital were published in the European Journal of Case Reports in Internal Medicine.  It became clear to doctors that the man had severe kidney injury and a deterioration of muscle tissue resulting from kidney failure, as well as a lactic acid buildup in his bloodstream.

Transferred to an intensive care unit, diagnosed with severe sepsis with skin death and blood clotting, he was treated with antibiotics but his condition continued to grow graver in the following 30 hours. By then doctors were able to diagnose brain disease, paralysis-caused intestinal blockage, blood clotting and kidney failure, all destroying his body. On entering cardiac arrest he was resuscitated, intubated, placed on a breathing machine, and treated for low blood pressure.

Doctors added another antibiotic and an anti-fungal treatment to his regimen following a test that indicated C.canimorsus infection, while some symptoms waned and others became more compromised, and in the end, no amount or type of treatment worked to save the man's life. All his extremities had gangrene; a CT scan showed severe brain swelling caused by lack of oxygen. He lived for 16 agonizing days following his hospital admission.

Researchers caution the public that C.canimorsus infections are blessedly rare, typified by a range of symptoms. And that most people who have contracted severe or fatal infections from the bacteria did so as a result of having had immune, spleen or alcohol abuse issues. Soberingly, this patient's medical history lacked any such conditions.

"The Capnocytophaga canimorsus bacteria is well known to infectious disease specialists as being part of the normal bacterial population that exists in the mouth of dogs, but not in cats or humans."

"Dogs represent a 'peculiar ecological niche for this bacterium [but it] doesn’t cause illness in dogs, and it usually doesn’t cause illnesses in anyone else, either."

"[On occasion, dog bites can be] complicated by this bacteria, but even then it’s rare. This case in unusual in the extreme. This man’s ‘best friend’ was simply being friendly, doing what thousands of other dogs do every day, slurping or licking their masters on their noses, mouths, and lips—it happens all the time."
"[There’s nothing wrong with immunodeficient people having dogs, they] just shouldn’t get that intimate with them."
William Schaffner, infectious diseases specialist, Vanderbilt University Medical Center, Nashville, Tennessee