This summer, Greg Manteufel of West Bend, Wisconsin, got very sick with a life-threatening infection.

Dawn Manteufel

Manteufel started feeling ill in June. Just hours after going to the hospital he went into septic shock.

Septic shock is the worst complication of sepsis, a body-wide crisis that can be triggered by an infection. In sepsis, germs trigger a cascade of immune system reactions that can lead to plummeting blood pressure, organ failure, tissue damage, and death.

The drop in blood circulation can damage organs and affect the limbs, sometimes leading to amputations to remove the dead tissue.

Some of the symptoms of sepsis are shivering, fever, feeling cold, extreme pain, sleepiness, confusion, clammy skin, shortness of breath, or feeling like you might die, according to the Sepsis Alliance.

Manteufel had both feet amputated, then additional surgery to remove more damage, which extended the amputation to just below his kneecaps, according to a GoFundMe page set up to help his family cope during the crisis.

He is scheduled for more surgery to remove parts of his hands and will need plastic surgery to reconstruct his nose, according to the page.

Sepsis can happen to anyone who has an infection somewhere in their body, even in small wounds like an infected hangnail.

However, it's most likely to happen in people 65 or older, children under age 1, and those with weakened immune systems or chronic medical conditions like diabetes, lung disease, cancer, and kidney problems, according to the Centers for Disease Control and Prevention (CDC).

Testing showed that Manteufel's initial infection was caused by a type of bacteria called Capnocytophaga canimorsus.

Capnocytophaga species of bacteria are found in the mouths of 57% of cats and 74% of dogs. They're normal flora that typically don't hurt the animal.

However, they can be transferred to humans through a dog bite or from close contact. In rare circumstances, the bugs can cause serious infections, according to the CDC.

It's not clear how Manteufel was infected with the bacteria, although Manteufel's wife, Dawn, told the Washington Post that Greg had been around eight different dogs before he got sick, including the couple's own dog. Any one of the dogs that licked him could have been the source of the infection, she said.

Manteufel's family noted there have been 500 cases in the US and Canada since 1976 in which people developed sepsis even without a history of dog bite.

About 3 in 10 people who get infected with the bacteria will die from it — sometimes within 24 to 72 hours of when symptoms start — so if you have been bitten by a cat or dog, seek care immediately, even if you feel fine, the CDC recommends.

Symptoms of a Capnocytophaga infection include blisters around a bite wound that appear within hours of the injury, fever, diarrhea or stomach pain, headache or confusion, muscle or joint pain, and redness, swelling, pain, and pus in a bite wound.

Manteufel is coping with the situation as best he can.

Dawn Manteufel

"During this process while his family and friends are in panic and chaos Greg has held his head high and is taking all the news like a beast. He is so thankful to be alive today and is taking one day at a time," according to his GoFundMe page.

BuzzFeed News has reached out to Manteufel's family and will update this story with additional information as it becomes available.

Theresa Tamkins is a health editor for BuzzFeed News and is based in New York.