When 48-year-old Greg Manteufel was admitted to a Wisconsin hospital in 2018, doctors immediately knew they were facing something extraordinary.
He hadn’t been involved in a serious accident. There were no major injuries, no obvious trauma, and nothing that could explain why his condition was deteriorating so rapidly. Just days earlier, he had been living a completely normal life with his family, working, staying active, and enjoying time with his dog.
Now, his organs were beginning to fail.
His blood pressure had dropped to dangerous levels, his body was slipping into septic shock, and the circulation to his arms and legs was rapidly disappearing. The medical team focused on keeping him alive while trying to identify the organism responsible for the devastating infection.
The laboratory results eventually pointed to an unexpected culprit: Capnocytophaga canimorsus, a bacterium that quietly lives in the mouths of many healthy dogs and cats.
What started as flu-like symptoms quickly became life-threatening
The first signs didn’t seem unusual.
Greg developed a fever, chills, muscle aches, and overwhelming fatigue. At first, the symptoms looked very similar to a seasonal viral illness. Within hours, however, he became much sicker. Nausea and vomiting followed, and his family realized something was seriously wrong.
By the time he reached the hospital, doctors diagnosed septic shock, a medical emergency in which the body’s response to an infection causes widespread damage to its own tissues and organs.
Without immediate treatment, the condition can become fatal in a very short time.
A bacterium most people have never heard of
The diagnosis surprised many people because the bacterium involved is virtually unknown outside the medical community.
Capnocytophaga canimorsus is commonly found in the mouths of dogs and, less frequently, cats. Animals carrying it usually show no signs of illness, and most owners never know it is there.
For healthy people, this bacterium rarely causes any problems. The immune system normally destroys it before it has a chance to spread.
That is why severe infections are considered exceptionally uncommon.
Did a dog’s lick really cause the infection?
This is where the story often becomes oversimplified online.
After Greg’s case received worldwide attention, many headlines claimed he “lost his limbs because his dog licked him.”
The reality is more complicated.
According to reports, Greg’s dog frequently licked him, and doctors believed the animal’s saliva was the most likely source of the bacterium. However, they could not prove exactly how the infection entered his body.
Medical experts explain that Capnocytophaga canimorsus usually enters through a bite, a scratch, or even a tiny cut or abrasion that may go completely unnoticed. There is no clear evidence that saliva touching completely healthy, intact skin normally causes this type of infection.
This distinction is important because it changes how the case should be understood.
Why doctors had no choice but to amputate
Despite aggressive treatment, Greg’s condition continued to worsen.
As septic shock progressed, his body redirected blood flow toward vital organs such as the heart and brain. Powerful medications used to maintain blood pressure also reduced circulation to his hands and feet.
Without enough oxygen, the tissue in his extremities began to die.
Doctors were eventually forced to make an incredibly difficult decision.
To save his life, they had to amputate both legs and significant portions of both arms.
The bacterium did not “eat away” at his limbs, as some social media posts suggest. The amputations were the result of severe septic shock, tissue death, and irreversible loss of blood supply.
Why cases like this are so uncommon
One question naturally follows Greg’s story: if many dogs carry this bacterium, why don’t these infections happen more often?
The answer lies in the human immune system.
Most people’s bodies eliminate the bacterium without difficulty. Severe infections are primarily seen in individuals with weakened immune systems, people who have had their spleen removed, those with advanced liver disease, or individuals with heavy alcohol use.
Even within these higher-risk groups, infections remain extremely rare.
Greg’s case attracted international attention precisely because he did not fit the typical high-risk profile.
Recognizing the warning signs
Early symptoms can easily be mistaken for a common viral illness.
Fever, chills, muscle pain, nausea, vomiting, and extreme fatigue are often the first signs.
As the infection progresses, symptoms may include confusion, difficulty breathing, very low blood pressure, purple skin discoloration, and signs of multiple organ failure.
Anyone who develops severe illness after an animal bite, scratch, or possible exposure of an open wound to saliva should seek immediate medical attention. In cases of sepsis, rapid diagnosis and treatment can make the difference between life and death.
The real lesson behind Greg’s story
Greg Manteufel survived an infection that could easily have been fatal.
His recovery required multiple surgeries, months of rehabilitation, and learning how to adapt to life with prosthetic limbs. Since then, his story has been shared around the world, often with headlines that emphasize the shocking outcome while overlooking the medical facts behind it.
His experience should not be viewed as evidence that dogs are inherently dangerous. Millions of people interact with their pets every day without experiencing anything remotely similar.
Instead, Greg’s case serves as a reminder of how unpredictable severe bacterial infections can sometimes be and why unusual symptoms should never be ignored.
Simple precautions—cleaning bites and scratches thoroughly, preventing animal saliva from coming into contact with open wounds, and seeking prompt medical care when serious symptoms develop—remain the best way to reduce an already very small risk.
For the overwhelming majority of dog owners, their pets remain safe companions. Greg’s story became global news not because it represents a common danger, but because it is an extraordinarily rare medical exception.