We are all guilty of letting our dogs and cats give us kisses. We can't help it. They are so sweet and just want to show us love. The problem is that in some cases these kisses can become deadly.

They are doing it because they love us, but there have been times when their love was dangerous to our health. Julie McKenna learned this the hard way when she was brought into the hospital with her arms and legs turning purple and was almost unable to speak. Her body had gone into septic shock and the doctors took two weeks to figure out the cause.

Her dog had licked her foot that had a very mild burn on it week before, but she didn't even think to mention it, but the bacteria known as Capnocytophaga canimorsus in her dog's mouth had caused an infection.

The bacteria can be found in even healthy dogs and cats, but when it gets into the human bloodstream it can be catastrophic.

Roughly 10 to 15 percent of dog and cat bites become infected. But as it turns out, it doesn't need to be a full on bite to infect you, they just need to lick an open wound. Each time your dog gives you a big ol' slobbery kiss, or your cat licks you with their tiny sandpaper tongues, you run the risk of infection.

It can be as simple as getting just a little bit of the bacteria into the bloodstream and then you may end up like McKenna who ended up needing her left leg amputated below the knee, part of her right foot amputated, as well as her fingers and toes.

Here's why the bacteria is so dangerous...

The reason why the bacteria harms your body and not theirs is that it is such different bacteria than we have in our bodies.

Bacterial geneticist, Floyd Dewhirst, studied the different strains of bacteria that were in an animal's mouth compared to what was in a human's, and the differences were astounding. "If you look at humans and dogs, we only saw about 15 percent that are the same species," he said. This means that the human body can't fight off the bacteria from a dog or cat's body.

While you may think that it's not a big deal, the bacteria that they deposit will stay on your skin for hours.  "If you're licked by a dog, and someone were to take a Q-tip five hours later and rub that spot, they could recover over 50 different species of dog-mouth bacteria," Dewhirst said.

While it's got the potential to be dangerous if they are licking open wounds, allowing a dog or cat to lick unbroken skin isn't likely to lead to any issues.

I guess you just have to make sure that you wash your hands and keep your cuts clean, but honestly any of us dog and cat lovers know, you can't really stop your pet from smothering you with kisses. And honestly, we really don't want to.

Source - National Geographic