By Sam Rega

People usually fall into two camps: those who like getting kisses from their dog, or those, like me, who can’t stand it. Here are the reasons why dogs want to lick your face, and why you might want to avoid that kind of affection, even if you do enjoy it.

Dr. Leni K. Kaplan of Cornell University College of Veterinary Medicine explains what drives dogs to give you slobbery kisses, and why it’s actually pretty gross. The reason they lick your face comes down to three main factors:

Licking is one of their ways to communicate, especially with other dogs.

You, as their owner, have a familiar scent and taste that comforts them.

They want attention.

If you’re a healthy person, getting a little dog saliva on your skin is no big deal. There’s very little risk it will cause any problems since your skin doesn’t absorb it. When they lick your face, however, zoonotic pathogens like Clostridium, E. coli, Salmonella, and Campylobacter can make their way into your body through your eyes, mouth, and nose. The same thing can happen if they lick your hands and then you touch your face. But where does this nasty stuff come from? Dogs release these nasty bugs in their feces, the dog then eats the feces, and finally the dog licks your face. That’s why it’s best to avoid your dog’s kisses, especially if you have a compromised or underdeveloped immune system.