There have been several videos that have gone viral about dogs "crying," shedding what viewers perceive as "emotional tears" but do dogs cry tears from emotions, just like humans do? The crying dogs in question are often described as crying because they are grieving, depressed or feeling rather strong emotions such as joy and gratitude after being rescued or after mother dog has been re-united with her puppies, but can dogs really cry tears from emotions just like we do? Read on before passing Rover that box of Kleenex.
Crying in Humans
Do dogs cry tears like humans do? First, we must take a look at the role of crying in humans. Crying, the shedding of tears from the eyes in a response to emotions, is something quite common in the human world. Whether crying from sorrow, joy, sadness or happiness, the ability to shed tears makes us quite unique beings in the animal world.
"In the sense of producing emotional tears, we are the only species," explains Dutch scholar Ad Vingerhoets in the book "Why Only Humans Weep: Unraveling the Mysteries of Tears." We essentially start crying from birth, and retain the ability to cry until death.
Crying in humans likely had some evolutionary purpose and there are several theories as to why this behavior persisted so far. In babies, it's an aid to survival. Crying is a baby's most effective means of communication which aims to solicit attention and comfort from the mother or carer, a behavior that must have had an important role back in time when our ancestors lived in a dangerous environment, further explains Ad Vingerhoets. The big question though is why do humans continue to cry into adulthood?
Another equally important question is why do we shed tears when we cry? The scientific debate has been going on for quite some time with several theories. Charles Darwin considered human crying pretty much useless. In 1872 claimed:
"We must look at weeping as an incidental result, as purposeless as the secretion of tears from a blow outside the eye." ~Charles Darwin
A Few Theories
Many experts disagree with Darwin's consideration that crying is purposeless. One theory proposed by biochemist William Frey (1985) is that when we cry we remove toxic substances from our blood which accumulate when we're under stress. This makes sense considering how much better we often feel after weeping! Another valid theory, keeping evolution in mind, comes from Dutch ethologist Frans Roes, (1989).
He theorizes that the facial expressions of an adult crying mimic the expressions of a helpless child. Crying therefore may have worked as a way to gain protection from others, something that may have been favored by natural selection as crying triggers empathy.
Another great theory comes from Israeli evolutionary biologist Oren Hassen. Crying blurs our vision which interferes with our ability to demonstrate aggression. Tears are therefore a honest signal that tells others that we mean no harm, therefore fulfilling an appeasing function that facilitates social bonding and trust. Finally, Ad Vingerhoets also points out how crying may have attracted predators whereas the visual impact of seeing tears may have been an effective way to attract the attention of others without attracting predators.
"Compared to most other animals, humans also have very sophisticated developed facial musculature that we can use to express nearly all emotions." ~Ad Vingerhoets
Crying in Dogs
Do dogs cry? Do they shed tears like humans? The answer is yes and no depending on how we define crying. If we think of crying as the shedding of tears as a reaction to emotions, no, dogs do not cry that way. Sure, dogs have the necessary hardware to make tears happen, but they don't get teary eyed as a response to emotions like humans do.
Crying remains a human trait and despite reports of non-human animals crying, several interviews with veterinarians, animal trainers, zoologists and zoo directors reveal that evidence of emotional crying in non-human animals is weak at best and likely something extremely uncommon, explains Ad Vingerhoets.
The fact that dogs don't cry in the same way as humans do though doesn't mean that dogs aren't capable of feeling emotions. Dogs have the ability to manifest most basic emotions such as joy, fear, anger, disgust and even love, explains Stanley Coren, author and Professor Emeritus in the Department of Psychology at the University of British Columbia.
“Science can’t prove it, but there’s absolutely no doubt in my mind that dogs and cats have real feelings, just as powerful as our own. It’s just that I have never heard of a case of a dog or cat getting upset or depressed, and then crying real tears as a response.” ~ Nicholas Dodman.
Dog Versions of Crying
While most scientists seem to agree that humans are the only animals to shed emotional tears, dogs have their own versions of "crying" that are closely related to the human version of crying. When puppies are born, as an altricial species, they are helpless beings who heavily rely on their mothers.
Just like human babies, they need a way to attract their mothers in times of need. Instead of crying by shedding tears, they will make distinct vocalizations (whining) to get attention from their mother if they're sick, hungry or cold.
Once the puppies grow up they may still whine when they find themselves in situations that require attention. Several dog trainers describe the distressed whining of dogs suffering from separation anxiety quite similar to the whining of puppies in search of their mothers.
Yelping, the acute vocalization often heard when a dog gets hurt, is another version of "crying" that may have an evolutionary, survival advantage in dogs too. We really don't know if dogs may feel empathy among each other in the same way as humans do, but when puppies play rough, a "yelp" will often do in getting the rough pup to learn to play more gently. In adult dogs, whining and yelping continues to be used to manifest various emotions and/or physical pain.
Dogs With Crying Eyes
As mentioned, dogs have the necessary hardware to make tears happen. Indeed, the production of tears is necessary for healthy eyes. Dog eyes indeed produce tears for the purpose of lubricating the eye and washing away the irritants.
In the videos of dogs crying that went viral, there may be chances that the videos are fake and artificially created (perhaps for the purpose of gaining traffic) or that the dogs had an underlying eye disorder that caused an abnormal, excessive tearing of the eyes.
There are several eye disorders that can cause excessive tearing of the eyes in dogs. The medical term for excessive tearing in dogs is "epiphora" and it can stem from an obstruction of the dog's tear duct or an overproduction of tears with a drainage system that cannot keep up, explains veterinarian Dr. Noelle McNabb. So before passing your dog a Kleenex, a better option may be to see the vet.
"If your dog has fluid coming out of its eyes, you might assume that the animal is crying. However, it's important for pet owners to note that dogs cannot cry in the way that humans do. If a dog's eyes are discharging liquid, it is because something is wrong, not because the animal is overcome with emotion." VCA Animal Hospitals
Video of dog crying tears. Hoax or True Tears? Without doubt living in a shelter is sad for dogs.
- Vingerhoets, A. (2013). Why Only Humans Weep: Unravelling the mysteries of the tears. Oxford University Press.
- Psychology Today: Why We (and Only We) Cry, by Mark van Vugt Ph.D, Retrieved from the Web on February 5, 2016
- Walter, Chip (December 2006). "Why do we cry?". Scientific American Mind17 (6): 44.
- Psychology Today: Which Emotions Do Dogs Actually Experience?, by Stanley Coren, retrieved from the Web on February 5, 2016
- New York Times: Biological Role of Human Tears Emerges Through Recent Studies,Dr. William H. Frey
- Sun Sentinel, Do Dogs Cry Real Tears? Retrieved from the Web on February 5, 2016
- VCA Animal Hospitals: Can Dogs Cry? Retrieved from the Web on February 5, 2016