There’s no doubt dogs are affectionate creatures. And they have numerous ways of showing it. So what’s the deal when your furry friend comes up and gives you a big ol’ pooch smooch? Let’s take a tongue-in-cheek look into why.

Dogs are oral creatures and gather a lot of information about their surroundings through taste and smell. Maybe you’re salty after a sweaty run. Maybe you’ve got barbecue sauce on your face. “Dogs can smell a lot better than we can,” says Opens a new windowDr. Jo Gale, BVetMed CertLAS MRCVS, Senior Manager, Global Science Advocacy at Waltham Petcare Science Institute, “so they find a lot more things interesting to lick than we can.” This despite the fact dogs only have about 1,700 taste buds compared to around 9,000 in humans.
In a poll* of dog owners, IAMS™ found a large majority (75%) believe dogs lick people to offer friendliness. That’s definitely a correct assumption. Licking has been a social behavior among dogs since the days of great-great-great granddaddy wolf. 'It’s a standard canine greeting to lick others around the face,” agrees Opens a new windowJames Serpell, B.S., Ph.D., Professor of Humane Ethics & Animal Welfare at the University of Pennsylvania School of Veterinary Medicine. “Junior members of the pack will run around and lick the mouths of more senior members.” Your dog considers you part of their pack, so it’s their way of greeting and welcoming you. Or maybe you still have that barbecue sauce on your face.
In ancient Greece, dogs at the shrine of Asclepius were trained to lick patients. In the Middle Ages, Saint Roch was said to have been cured of a plague of sores through his dog’s licks. The French even have a saying, “langue de chien, langue de médecin,” which translates to, “a dog’s tongue, a doctor’s tongue.”

Don’t cancel your health insurance just yet. While dogs’ saliva does have some possible bactericidal properties against some types of bacteria, it can put you at the risk of exposure to others. Too much licking can also reopen the wound and cause further infection. With modern medicine, you’re much better off hitting the first-aid kit.
And that myth about dogs’ mouths being cleaner than humans’? Not true — both contain over 600 types of bacteria. You’re welcome for that image.
While an occasional canine kiss is “aww”-inducing, some dogs can overdo it to the point of annoyance. When this happens, the best thing to do is “completely ignore it and give no attention,” suggests Dr. Jo Gale. “When they stop, provide them with attention.” Over time your dog will learn to scale back on the smooches.
*Surveyed U.S. dog owners, age 18+
Sample Size: n=201
Fielded May 8-10, 2020
As your dog matures, his body functions change. He might have decreased immune-system function, deterioration of skin and coat quality, and more frequent intestinal problems. So it makes sense that what a mature dog eats might also need to change.
Throughout a dog's life, a process called peroxidation occurs. This is a normal process the body uses to destroy cells that outlive their usefulness and to kill germs and parasites, but this process also can destroy or damage healthy cells. As a dog ages, the damage caused by peroxidation accumulates and, in turn, increases the risk of certain problems such as infections.
Antioxidants are naturally occurring components in the body (but also can be acquired through diet). They help maintain overall health by neutralizing the peroxidation process of cellular molecules.
Research sponsored by IAMS™ found that dogs fed a diet rich in antioxidants such as vitamin E had improved immune responses and vaccine recognition. This might be especially important for mature/senior dogs, because IAMS research has found that, as dogs age, immune responses can decrease.
Eating a complete and balanced diet with omega-3 fatty acids, such as those found in vitamin-rich fish oils, also helps rejuvenate dry skin and develop a healthy, lustrous coat.
Aging dogs might have higher numbers of unfavorable bacteria and lower numbers of beneficial bacteria in their intestines, which can result in clinical signs of gastrointestinal problems (such as diarrhea). A diet with a moderately fermentable fiber source such as beet pulp can help maintain intestinal health. Beet pulp provides energy for the cells lining the intestine and promotes proper stool formation.
Different dogs show signs of aging at different times, and much of this variation is associated with size. Larger dogs generally appear mature/senior sooner than smaller dogs. The table below can show you when your dog should start a mature diet with a food such as IAMS ProActive Health™ Mature Adult.
Dog Weight and Transition to Mature/Senior Foods
| Weight Range | Age to Begin Transition |
|---|---|
| More than 90 lbs | 5 years |
| 51 to 90 lbs | 6 years |
| 21 to 50 lbs | 7 years |
| Up to 20 lbs | 7 years |