Dogs have been companions to humans for thousands of years, evolving from wild wolves into the diverse and beloved pets we know today. Throughout this time, a plethora of myths and misconceptions about dogs have emerged, some of which persist despite scientific evidence to the contrary. This detailed post will explore several of these myths and misconceptions, debunking them with scientific findings.
Myth 1: Dogs See in Black and White
The Myth
A common belief is that dogs can only see in black and white, leading many to think that their world is devoid of color.
The Reality
Dogs do see colors, but not in the same way humans do. Humans have three types of color receptors, or cones, in their eyes (red, green, and blue), which allow them to see a broad spectrum of colors. Dogs, on the other hand, have only two types of cones (blue and yellow). This means their color vision is similar to that of a human with red-green color blindness. Dogs can see shades of blue and yellow quite well, but red and green appear as shades of gray or brown to them.
Scientific Evidence
Research published in the Proceedings of the Royal Society B confirmed that dogs have dichromatic vision. Experiments involving color discrimination tasks showed that dogs can distinguish between blue and yellow, but struggle with red and green .
Myth 2: Dogs Age Seven Years for Every Human Year
The Myth
A widely accepted rule of thumb is that one dog year is equivalent to seven human years. This myth likely arose from a simple division of average human lifespan by average dog lifespan.
The Reality
The aging process of dogs is far more complex and varies significantly by breed and size. Smaller breeds tend to live longer than larger breeds, and their aging process is not linear.
Scientific Evidence
A study by the University of California, San Diego School of Medicine proposed a new formula for calculating dog years based on DNA methylation patterns. This formula, which takes into account the rapid aging during the early years of a dog’s life and a slower rate later on, provides a more accurate representation. For example, a one-year-old dog is roughly equivalent to a 30-year-old human, but the rate of aging decreases after the initial growth spurt .
Myth 3: A Wagging Tail Always Means a Happy Dog
The Myth
Many people believe that a dog wagging its tail is always a sign of happiness and friendliness.
The Reality
While a wagging tail can indicate happiness, it is not a universal signal. Tail wagging can also signify anxiety, agitation, or even aggression, depending on the position and movement of the tail.
Scientific Evidence
Research has shown that the direction of the tail wag can convey different emotions. A study published in Current Biology found that dogs wag their tails to the right when they experience positive emotions and to the left when they experience negative emotions. Additionally, the speed and height of the wag can provide further context: a high, stiff wag can indicate aggression, while a low, slow wag might signify uncertainty or submissiveness .
Myth 4: You Can’t Teach an Old Dog New Tricks
The Myth
This adage suggests that older dogs are set in their ways and incapable of learning new behaviors or skills.
The Reality
Dogs of any age can learn new tricks and behaviors, although older dogs might take a bit longer due to established habits or physical limitations.
Scientific Evidence
Studies on canine cognition have shown that dogs retain their ability to learn throughout their lives. The key to training older dogs is patience and consistency. Research published in the journal Animal Cognition found that senior dogs can learn new tasks, although they may need more repetitions and positive reinforcement than younger dogs .
Myth 5: Dogs Feel Guilty When They Do Something Wrong
The Myth
Many dog owners believe that their pets feel guilty after misbehaving, as evidenced by their “guilty” expressions.
The Reality
What appears to be a guilty expression is actually a response to the owner’s behavior and tone of voice, not an indication of the dog’s understanding of wrongdoing.
Scientific Evidence
A study by Alexandra Horowitz at Barnard College examined this phenomenon. The research found that dogs’ “guilty” looks were more strongly correlated with being scolded by their owners than with any actual misbehavior. The dogs displayed these behaviors even when they had not done anything wrong, indicating that the expression is a submissive response to human cues rather than an acknowledgment of guilt .
Myth 6: Dogs’ Mouths Are Cleaner Than Humans’
The Myth
A persistent belief is that a dog’s mouth is cleaner than a human’s, leading some to think that dog bites are less likely to cause infections.
The Reality
Dogs’ mouths are full of bacteria, just like human mouths. The types of bacteria differ, but neither is inherently cleaner or safer than the other.
Scientific Evidence
Studies comparing the bacterial flora of human and dog mouths have shown that both harbor a variety of bacteria, some of which can be harmful. While dog saliva has some antibacterial properties, it also contains bacteria like Pasteurella, Capnocytophaga, and Staphylococcus that can cause infections in humans, especially if the skin is broken .
Myth 7: Dogs Eat Grass to Induce Vomiting
The Myth
It is commonly believed that dogs eat grass when they feel sick and want to induce vomiting.
The Reality
While some dogs may vomit after eating grass, most do not. Dogs eat grass for various reasons, including boredom, improving digestion, or simply because they like the taste.
Scientific Evidence
A survey conducted by veterinarians at the University of California, Davis, found that less than 25% of dogs regularly vomit after eating grass, and only 10% show signs of illness beforehand. This suggests that grass eating is a normal behavior for dogs and not necessarily linked to sickness .
Myth 8: Purebred Dogs Are Healthier Than Mixed Breeds
The Myth
Some people believe that purebred dogs are healthier and superior to mixed breeds.
The Reality
Purebred dogs are often more susceptible to genetic disorders due to inbreeding. Mixed-breed dogs generally have a lower risk of inherited health issues due to greater genetic diversity.
Scientific Evidence
A study published in the Journal of the American Veterinary Medical Association analyzed the health records of over 27,000 dogs and found that mixed-breed dogs had a lower prevalence of certain genetic disorders compared to purebreds. Purebreds are more likely to suffer from conditions like hip dysplasia, heart disease, and certain cancers .
Myth 9: Dogs Only Understand Simple Commands
The Myth
Many believe that dogs can only comprehend basic commands like “sit,” “stay,” and “come.”
The Reality
Dogs are capable of understanding a wide range of words, gestures, and even human emotions. They can learn complex sequences of actions and respond to subtle cues.
Scientific Evidence
Research by psychologist Stanley Coren and other scientists has shown that dogs can understand up to 165 words, with some exceptional dogs learning more than 200. Border collies, in particular, have demonstrated the ability to understand and perform complex tasks, as evidenced by a famous border collie named Chaser, who learned over 1,000 words and could differentiate between objects by name .
Check out our Blog about “Diving into Canine Variety” to learn more about different dog breeds.
Myth 10: Spaying or Neutering Will Change a Dog’s Personality
The Myth
There is a belief that spaying or neutering a dog will significantly alter its personality, making it less playful or more aggressive.
The Reality
Spaying or neutering can influence certain behaviors related to reproduction, such as marking territory or roaming, but it does not fundamentally change a dog’s personality.
Scientific Evidence
Studies have shown that while spaying and neutering can reduce behaviors driven by hormones, such as aggression toward other dogs and mounting, they do not alter a dog’s basic temperament. The primary changes observed are related to a reduction in hormone-driven behaviors, not a change in the dog’s overall character .
Myth 11: Dogs Can’t Recognize Themselves in Mirrors
The Myth
It is often stated that dogs cannot recognize their own reflection in a mirror, suggesting a lack of self-awareness.
The Reality
While dogs may not recognize themselves in mirrors in the same way humans do, they are capable of a different form of self-recognition through scent.
Scientific Evidence
A study conducted by Roberto Cazzolla Gatti used a “mirror test” for scent, where dogs were exposed to their own urine mixed with an unfamiliar scent. The dogs spent more time investigating the modified scent, indicating they recognized their own scent and noticed the alteration. This suggests that dogs have a sense of self-awareness, but it is primarily based on olfactory cues rather than visual ones .
Myth 12: Dogs’ Saliva Can Heal Wounds
The Myth
A longstanding belief is that dogs’ saliva has healing properties and can help wounds heal faster.
The Reality
While dog saliva contains some antibacterial compounds, it also harbors bacteria that can potentially cause infections.
Scientific Evidence
Research has shown that while dog saliva does contain enzymes like lysozyme and peroxidase, which have antibacterial properties, it also contains bacteria that can be harmful if introduced into a wound. Therefore, licking can do more harm than good, and wounds should be properly cleaned and treated with appropriate medical care .
Myth 13: Dogs Are Colorblind
The Myth
A variation of the myth that dogs see in black and white is the belief that dogs are completely colorblind.
The Reality
As mentioned earlier, dogs can see colors, but their color vision is limited compared to humans. They see the world in shades of blue and yellow.
Scientific Evidence
Numerous studies on canine vision have confirmed that dogs possess dichromatic vision. This means they have two types of color receptors, allowing them to distinguish between certain colors, particularly blues and yellows, but not reds and greens .
Myth 14: Only Certain Breeds Make Good Service Dogs
The Myth
It is often thought that only specific breeds, like Labradors or German Shepherds, can be trained as service dogs.
The Reality
While some breeds are more commonly trained as service dogs due to their characteristics, many breeds can be trained for service work depending on the individual dog’s temperament and abilities.
Scientific Evidence
The suitability of a dog for service work depends more on individual traits than on breed. A study published in the journal Frontiers in Veterinary Science found that temperament and trainability are the key factors in determining a good service dog. While certain breeds like Labradors are preferred for their reliability and demeanor, dogs of various breeds and mixes can successfully perform service roles if they possess the necessary qualities .
Check out our Blog about “Diving into Canine Variety” to learn more about different dog breeds.
Myth 15: Dogs Eat Grass When They Are Sick
The Myth
A commonly held belief is that dogs eat grass only when they feel sick to induce vomiting.
The Reality
While some dogs might eat grass when they feel nauseous, most dogs eat grass out of habit, for its taste, or as a form of dietary fiber.
Scientific Evidence
A study conducted by the University of California, Davis, involving surveys of dog owners, revealed that grass-eating is a normal behavior in dogs. Less than 10% of dogs appeared to be ill before eating grass, and less than 25% vomited afterward. This indicates that grass-eating is not primarily linked to sickness .
Dogs are truly remarkable creatures with complex behaviors and capabilities that often surpass common misconceptions. By debunking these myths with scientific evidence, we can better understand and appreciate our canine companions. Whether it’s recognizing their unique way of seeing the world, understanding their learning abilities at any age, or appreciating their emotional responses, a deeper knowledge helps us form stronger, more informed bonds with our dogs. As we continue to learn and grow alongside our furry friends, it’s essential to base our care and training practices on facts rather than myths, ensuring a healthier and happier life for both dogs and their owners.