Why do dogs lick their wounds? Seeing dogs lick their wounds is something so common that the saying "licking one's wounds" has become a figurative way to depict a person's recovery from defeat or a bad experience. Unlike us though obviously dogs do not figuratively "lick their wounds" to recuperate after a negative experience, their licking instead is straight to the point as dogs have their own plausible reasons to engage in this activity.
In this article, we will be looking at some reasons why dogs may lick their wounds and we'll debunk some common myths associated with wound-licking behaviors in dogs.
Instincts at Play
As soon as puppies are born, mother dog licks her puppies vigorously to help them breath. She will also lick their bottoms to stimulate them to eliminate. As the pups grow, they will lick around mother dog's mouth upon greeting her. Licking behaviors are a form of communication in dogs and are deeply ingrained as dogs do not have dexterity in their hands nor opposable thumbs as humans do. They instinctively use their mouths and tongues as we use our hands.
When it comes to licking wounds, if we try to put ourselves in a dog's shoes, we can imagine that there must be several mechanisms that draw a dog's attention to the wound. Pain, would attract a dog's attention to the area, but so would the wound's appearance and smell. A dog is used to seeing his skin covered with fur, so an open wound must immediately catch his attention. The smell and taste of blood likely further play a role triggering licking behaviors.
A Good Sensation
On top of the dog being attracted to the wound, most likely licking it must also feels good. According to Watkins and Tasker Veterinary Group, there's belief that the act of licking releases endorphins, natural opiates that provide a sense of wellbeing in the dog's brain. Soon, the licking the wound behavior becomes the dog's standard operation procedure that warrants a dog owner's attention before too much damage is done.
Mom's Antiseptic Recipe
A study conducted by Benjamin L. Hart, Karen L. Powell, found that dog saliva has some antiseptic properties. In late pregnancy, prior to giving birth, and right after birth, mother dogs tend to instinctively lick their own mammary glands and rear ends. This licking, according to the study might have a protective role.
When puppies are born, they are vulnerable to pathogens as their gut is sterile and lacks the beneficial flora meant to keep the population of bad bacteria at bay. By licking her mammary glands and rear end, mother dog's saliva has the potential for killing two potentially life threatening bacteria, E-coli and Streptococcus, which are known for causing life threatening infections in vulnerable day-old puppies. Therefore one can deduce that mother dog's licking, just before, and right after birth, is an adaptive behavior necessary for the pup's survival.
Nature's Natural Neosporin
The same study above went on to determine if a dog's saliva also has antiseptic qualities when dogs lick their wounds. It makes sense for dogs to lick their wounds when in their past, living in the wild, they lived in dens, and frequented other questionable places, where they were routinely exposed to E-coli bacteria.
While dog saliva appears to have some mild antibacterial effects against E-coli and streptococcus, the studies showed that saliva didn't have a significant effect on other pathogens such as staphylococcus, which explains why this pathogen is so often found in dogs suffering from skin infections (46 percent of infections involved staph, while only 9 and 17 percent involved respectively streptococcus canis and E-coli.)
At a Closer Glance
What exactly does saliva contain that it makes it beneficial? Dr. Nigel Benjamin, a clinical pharmacologist with St. Bartholomew's Hospital and the London School of Medicine and Dentistry, found wound-licking benefits in both humans and dogs. For example, he found that when human saliva contacts skin, nitrite breaks down into nitric oxide, which helps protect skin injuries from unwanted bacteria. Additionally, lactoferrin and lactoperoxidase contained in saliva act as natural antibiotics reducing the likeliness of an infection, which, left untreated, can put an animal’s life at risk.
Everything in Moderation
We don't know if dogs are fully aware of some of the benefits of cleaning their wounds, but one thing is for sure, when things get out of hand, the dog may end up with more problems than bargained for. Constant licking will not only delay healing, but will also irritate the skin, explains veterinarian Betsy Brevits, in the book "The Complete Healthy Dog Handbook."
On top of that, not all bacteria in the dog's mouth is good and some types are better off staying where they belong to. Sure, if the dog was out in the fields and he licked his wound from dirt and debris, this temporary licking may have been somewhat beneficial in removing some contaminants, but things can get particularly problematic when a dog starts obsessing about licking, or worse, starts licking a surgical incision.
Vets go to great lengths to protect a surgical incision site before, during and after surgery. They scrub and flush the area with antiseptics, use sterile equipment, wear sterile gloves, stitch the area closed, prescribe antibiotics and recommend Elizabethan collars and anti-lick devices t discourage dogs from licking. When a dog licks a surgical incision, he's contaminating it, not cleaning it, explains veterinarian Dr. Jennifer Coates.
A Word of Caution
One may assume that if dog saliva does has some antibacterial properties, allowing a dog to lick a human's wound should help it heal. Not so fast. Not all bacteria in saliva are good. There are several horror stories of dog licks gone bad. According to The Lancet, a patient with right-sided ruptured eardrum developed meningitis as a result of Pasteurella bacteria transmitted by a dog who frequently licked his ear. In another scary case, a dog's lick took the life of Mrs. Kavanagh, from the UK. Her terrier's affectionate lick introduced bacteria into a small cut she had, and being without a spleen, she was sadly unable to fight off the infection. Of course, these are quite rare occurrences, but they make you think twice before letting your dog lick your wounds.
Did you know? Some dogs develop a condition known as acral lick dermatitis, where the dog's excessive licking may cause lead to ulcerated lesions generally found on the dog's forelimbs.