What has your dog been doing?
Before you kiss a dog, or let a dog kiss your face, “you have to think of where their nose has been,” Fobian says. “Has it been inside a dead opossum on the side of the road, or the posterior of another dog, or in the litter box?”
Don’t think that kissing your dog on his snout or the top of his head is safer than on the mouth. When a dog has an infection — say, in his ear — germs can end up all over his body through scratching, Fobian says. And there’s a good chance whatever’s in his mouth will end up on his coat through slobber and licking.
Could you make each other sick?
Human and dog mouths have “a large number and a wide variety of bacteria,” Fobian says. Fortunately, most of it doesn’t make us sick, but some can. Parasites like hookworm, roundworm, and giardia can be passed from dog to human through licking. Salmonella, too, can be passed from your dog to you, or vice versa.
Viruses tend to affect one species or the other; you’re not going to give your dog a cold, and he won’t be giving you his cough.
If you’re sick, think twice
If you’re not healthy, skip it. People with weak immune systems should simply avoid kissing pets, Fobian says. That includes those with HIV/AIDS, those who have had an organ transplant, and those who are on medicines for cancer that limit the body’s ability to fight off infection.
Some dogs may not like you to put your face close to theirs.
A dog who doesn’t want to be kissed will show his stress by leaning away, looking away, pursing and licking his lips.
“A lot of people miss those signs, and when they try to kiss the dog, the dog snaps at them,” says Melissa Bain, DVM, assistant professor at UC Davis School of Veterinary Medicine.
If your dog is giving you signs that this is not her thing, then don’t put her through it, Bain says.
It’s not much different from trying to kiss a human who doesn’t want to be kissed. “We respect people who are like that; we should also respect dogs who are like that,” Bain says.
