Picture this. You come home after a grueling day at work and see your dog eagerly waiting for you. You kneel or bend down to pet and hug your “best friend,” who responds by licking your face, playfully pawing you, and jumping into you. Sounds like a pretty harmless display of affection, right? Unfortunately, it’s not. One or two licks can kill you.

Fortunately, lethal licks are few and far between—but they can and do occur. Simple precautions can prevent pet-related illnesses and ensure your family’s safety, while preserving and protecting your relationship with your pet.

Dog saliva may be good for dogs, but it’s not good for you—ever.

Dog saliva contains hundreds of bacteria, viruses, and yeast. While most of a dog’s bacteria are only transmitted from one dog to another, some can be transmitted to people as well.

Humans are no strangers to bacteria. We harbor millions of bacteria in our own bodies. However, we have developed immunity against these bacteria. We have also evolved to tolerate and even benefit from them—the microbes in the human digestive tract are an excellent example.

On the other hand, dog saliva contains microorganisms against which our bodies have no immunity. Over 80% of the microbes in a dog’s mouth are not present in a person’s mouth.  Our bodies can neither tolerate nor benefit from these bacteria. If they enter your system, you stand a good chance of developing an infection or disease.

Unaware of the danger posed by dog saliva, most dog owners let their dogs lick and slobber all over their faces. They see this as a genuine display of affection, which it is, but don’t realize how harmful dog saliva can be. In fact, many people believe that a dog’s mouth is cleaner than a human’s. They believe that dog saliva is antiseptic and can promote healing. There is even a French saying that “a dog’s tongue is a doctor’s tongue.”

Dog saliva contains “histatins”—proteins that prevent infections and help heal wounds. When a dog licks an open wound, the histatins in its saliva prompt the epithelial cells—cells lining the body’s surfaces, on the skin, blood vessels, and elsewhere—to migrate to the wound area and close the wound. When dogs lick their wounds, their saliva not only serves as a defense against infection, but also speeds up the healing process.

Does that mean you should let your dog lick your wounds? The short answer is an emphatic “no.” While you might benefit from the histatins in your dog’s saliva, there are other microorganisms that can harm you.

For instance, dog saliva contains “anaerobic bacteria,” which do not live or grow when oxygen is present. If these bacteria enter an open wound, the resulting infection can be serious—even life-threatening. Other bacteria in dog saliva include E. coli and salmonella.

Your dog can transmit parasitic infections to you and your family.

Dogs tend to carry parasites like hookworms and roundworms, which can be transmitted to other animals and to people. If a pregnant dog is infected with roundworms, her puppies will also be infected. In fact, a one-week-old puppy can have as many as 30 million roundworm eggs in its intestines.

These parasites can be extremely prolific. A single worm can lay more than 100,000 eggs in one day. These eggs, and even live worms, are expelled through the dog’s vomit and feces. These parasites can be transmitted to you in different ways:

  • If your dog licks you immediately after licking its anus, its saliva is likely to contain roundworm eggs, which easily can be passed on to you.
  • If your dog defecates in your vegetable garden, the plants and soil are probably contaminated with parasites. If you don’t wash your hands after working in the garden and before eating or handling food, the chances of ingesting a parasite are extremely high. Similarly, if you eat raw produce from the garden without washing it, the risk of a parasitic infection is very high.
  • If you walk barefoot in the garden or accidentally step on dog feces, hookworms can easily penetrate your skin and cause an infection.

Dog saliva can cause catastrophic infections, resulting in amputations and even death.

Two case histories

Two years ago, a 70-year-old English woman was hospitalized in an unresponsive state. She improved after a few days of treatment, but soon developed a headache, diarrhea, and high fever, followed by kidney failure.

Blood tests showed that she had sepsis, a potentially deadly condition caused by a bacterial infection. Test results revealed that she was infected by “capnocytophaga canimorsus”—a type of bacteria commonly found in the mouths of both dogs and cats. It does not make dogs or cats sick, but can cause disastrous results in humans.

Because the woman owned a greyhound, the doctors concluded that the dog must have transmitted the bacteria to her. Interestingly, the woman was not bitten or even scratched by the dog. The dog had merely licked her, which caused the bacteria to enter her body.

After two weeks of intensive care, the woman fully recovered. Had she not been hospitalized when she was, the consequences could have been serious—gangrene, amputation, or even death due to multiple organ failure.

In June 2018, a Wisconsin man almost died from capnocytophaga infection. Initially, the man exhibited flu-like symptoms. The next day, he had diarrhea and could barely speak. He was rushed to a hospital. Within a short time, bruises and blemishes started appearing all over his body.

Doctors recognized it as a sepsis infection and sent him to another hospital, which was better equipped to treat him. By the time the man was hospitalized again, the infection had spread throughout his body. The muscles in his hands, legs, and nose had started dying, leaving the doctors no choice but to amputate parts of his arms, legs, and nose, and to perform several other surgeries to save his life.

Like the English woman’s case, this case did not involve biting or scratching—only licking. The capnocytophaga in the dog’s saliva had invaded the man’s body, nearly costing him his life.

Your body’s response to capnocytophaga infection

When you are suffering from a capnocytophaga infection, your blood pressure drops and the blood circulation in your limbs tends to decrease rapidly. Your immune system will then mount a massive response to the infection; this response may completely shut down the circulation in your limbs.

Even if the infection is cleared up with antibiotics, the complete lack of circulation may cause the muscles in the limbs to decay and die, at which point amputation becomes unavoidable.

Who is at risk?

Data from the Centers for Disease Control show that nearly 75% of dogs in the United States carry capnocytophaga, among other bacteria. People exposed to the bacteria rarely develop any infection or illness. While any person can become infected with the bacteria, some people are at a much greater risk than others. Those at greater risk tend to have other health issues:

  • People who drink excessively
  • People with diabetes, cancer, HIV, and other diseases that adversely impact the immune system
  • People undergoing chemotherapy
  • People whose spleens have been removed
  • Small children whose immune systems are not yet fully developed
  • Elderly people suffering from age-related immune dysfunction

People whose immune systems are compromised should be careful around dogs because of their heightened vulnerability to bacterial and parasitic infections.

There is more to be concerned about.

Dog saliva can cause allergies.

Contrary to popular belief, a dog’s fur is not the primary cause of human allergies. It’s the saliva that contains allergens. Dog saliva contains a number of proteins, many of which cause allergies in humans. When your dog licks you, and the saliva dries, the proteins in the saliva become airborne. If these proteins enter your system, you are likely to have an allergic reaction.

It’s not just your dog’s saliva that can hurt you.

Apart from the risk of bacterial and parasitic infections, there is one other reason not to allow your dog to lick you—particularly in the face. Dogs tend to dig their noses into trash cans, sniff under each other’s tails as well as their droppings, and chew all sorts of nasty things that they encounter.

So, apart from the microorganisms in their saliva, dogs’ muzzles are filled with germs that can harm you. Germs can easily enter your body through your mucous membranes—nose, mouth, and eyes. This is yet another reason why you should not encourage your dog to lick your face.

Take precautions to protect yourself and your family.

While the risk of contracting serious infections from your dog’s saliva is low, the consequences of some infections can be life-altering if not lethal. It’s safe to let your dog lick you, as long as you keep the dog’s face away from your face—particularly your nose and mouth.

There are several precautionary measures you can take to avoid the risk of bacterial and parasitic infections caused by dog saliva:

  • Wash your face and hands with soap and water after playing with your dog, after cleaning up your dog’s vomit or feces, and after gardening (especially if your dog does his business in the garden).
  • Never allow your dog to lick your nose or mouth.
  • Never allow your dog to lick open wounds anywhere on your body.
  • Do not walk barefoot in the garden, yard, or any other place where your dog regularly defecates. Do not allow your children to do so either.
  • Vaccinate your dog, particularly against rabies.
  • Deworm your dog regularly.
  • Keep your dog away from the feces of any other pets you have, as well as the feces of other animals on walks.

Harmful pathogens are more likely to be transmitted through a bite or a scratch, rather than a lick. Therefore, if you are bitten by any dog, seek medical attention even if the bite doesn’t appear serious.

Train your dog not to endanger you or other people.

If your dog has a habit of licking your face, biting, or pawing you, you should nip it in the bud. It is especially important to discourage your dog from biting anyone—even playfully. Training should begin as soon as a new dog—puppy or full-grown—joins your household.

Whenever the dog licks your face, bites or paws you in a way that can break your skin, let the dog know that this conduct is wrong: say “no!” in a stern voice, “ouch” if the dog bites, and turn your face away if the dog licks your face. You can also train your dog to control its bite pressure, so that a playful bite doesn’t break your skin.

Physical punishment is usually counterproductive. It can scare a new puppy or a newly acquired older dog away from you, defeating the purpose of getting a dog in the first place. In fact, physical punishment can increase aggression and belligerence in your pet, which defeats the purpose of training.

You can train your dog by yourself or hire a trainer, depending on (1) your dog’s age, breed, and level of aggression, and (2) given your dog’s individual characteristics, whether training your dog yourself is too challenging for you.

If you are bitten by someone else’s dog, rely on a full-service law firm to protect your interests.

Dog bites can have serious consequences. Because a dog’s saliva can infect you if its bite penetrates your skin, you should seek medical attention as soon as possible after being bitten. You may not know right away if a dog’s bite has exposed you to harmful bacteria. Take any symptoms of illness or infection seriously. If you suffer any serious injuries as a result of a dog bite, you should follow the guidance of medical professionals. Once your medical issues are under control, reach out to an experienced law firm with expertise in dog bite cases.

Like so many others who have placed their trust in us, you can count on Slater & Zurz LLP to thoroughly evaluate your rights, answer your questions, and recommend the best path forward for you, based on your particular circumstances and our expertise developed over the years handling dog-bite cases. Call or email our team of dedicated professionals for a free consultation. We’re here to serve your legal needs with persistence, determination, and the drive to win.