If you have ever had a significant other, you know the personal intimacy of a kiss. It’s not uncommon for lovers to share some tongue when they kiss.

If you are a dog lover like millions of Americans, it’s not uncommon for them to greet you with a kiss (a lick). My wife and I currently have two lovable Maltese, a male, Timothy, and a female Fiona. They learned early on while still puppies that ‘kiss’ means to give us a lick, generally on the tip of the nose or cheek, but sometimes in their exuberance they accidently slip us a tongue without trying to.

Most people react to that as something repulsive. I’ve heard many people say that dogs licking is unhealthy, after all, they lick their genitals and feet. Yet, I imagine that most of those people have no problem slipping some tongue with a loved one during a kiss.

So, which is healthier – human or dog saliva?

When is the last time you heard of a dog getting a tooth cavity? When was the last time you or someone you knew had a cavity?

Human saliva generally has a pH level of around 6.5 to 7.0, meaning that it is slightly acidic. This pH does little to prevent cavities from forming, as many of us know. However, a dog’s saliva has a pH of about 7.5 to 8.0, meaning it is more alkaline. This works to help prevent many tooth cavities from forming.

Human saliva not only is slightly acidic, but it also contains enzymes that help start the breakdown and digestion of food. Dog saliva doesn’t contain those enzymes, but does help in digestion by providing lubrication for food swallowed by dogs. It’s important for digestive purposes for people to chew their food to start the breakdown of nutrients, but dogs can gulp whole pieces of food without chewing. Their stomach and intestines do all the work.

Human saliva breeds bacteria. Dog saliva contains chemicals that serve as antibacterial agents. This is another reason people get tooth cavities more frequently than dogs.

This explains why a human bite is far more dangerous than a dog bite. Generally, dog bites don’t get infected, but human bites are different. A security guard at one of the large retail stores I was an assistant manager of, was bitten on the shoulder by a shoplifter resisting arrest. After the woman was subdued and turned over to police, the security guard was sent to the emergency room for treatment. The doctor told him that human bites are the worse and to be careful because it was likely to develop an infection. It did infect and became so serious that he lost about 75% of the use of his arm, costing him his job as a security officer.

Although dog saliva has an antibacterial agent, it is possible for them to transfer a bacterium to a human through its licking. A good example is the current news of puppies being sold by one pet store chain that have infected at least 55 people in 12 states with Campylobacter. This bacterium is generally confined to dogs but in humans, it causes fever, vomiting and diarrhea and can make a person quite ill.

If you have an allergy to dogs, especially long-haired dogs, chances are your allergy is not their fur, but their saliva. Most people allergic to cats (that’s me) are actually allergic to the cat saliva that is transferred to their fur while grooming. Dogs may not groom as much or in the same way that cats do, but they do lick their fur more than you realize and like in cats, it’s the saliva that causes the allergic reaction, not the fur.

So, a dog’s mouth is far cleaner and healthier than a human’s mouth, but it is not without its risks. Will I stop getting kissed from Timothy and Fiona? Not on your life as it is also an important part of their social bonding with us. Will I intentionally allow them to slip me some tongue on the mouth? Not intentionally, but when they are excited to see you and you are trying to say anything to them or someone else it’s hard to avoid.

If I had a choice of who to get bit by, I would choose a dog bite any day over a human bite. I’ve seen both and the human bites have done far more damage from infection than dog bites.