15 Myths About Dogs That You Still Believe

Sadly, even the most devoted dog owners can fall victim to common misconceptions about their furry companions. While some myths are harmless, others might lead to mistakes in training, health care, or communication with your pup. In this list, we’ll debunk 15 widespread myths about dogs that you might still believe.
Dogs See in Black and White

Many people believe that dogs see the world in grayscale, but that’s not true. Dogs have fewer color-detecting cells (cones) in their eyes than humans, which limits their color perception. They see the world in shades of blue and yellow, similar to a person with red-green color blindness.
A Wagging Tail Always Means a Happy Dog

A wagging tail is often mistaken as a universal sign of happiness, but it’s more complex than that. The position of the tail (high, low, or neutral) and the speed of the wag can indicate a range of emotions. For example, a high, stiff wag can signal excitement or dominance, while a low, slow wag might indicate insecurity or submission.
Dogs Age 7 Years for Every Human Year

The “7-year rule” was a simple way to convey that dogs age faster than humans, but it’s not accurate. Dogs mature quickly in their first two years (comparable to a human reaching their late teens or early twenties). After that, aging depends on the breed and size. Smaller breeds like Chihuahuas age more slowly, while larger breeds like Great Danes age faster.
A Dry Nose Means a Sick Dog

While a dry nose can sometimes indicate dehydration or illness, it’s often caused by environmental factors. For instance, lying in the sun, sleeping, or being in a heated room can cause your dog’s nose to dry out temporarily. The texture and moisture level of a dog’s nose vary throughout the day.
Dogs Eat Grass Because They’re Sick

Dogs eating grass is a common behavior and doesn’t necessarily mean they’re ill. Some dogs eat grass to aid digestion, while others do it out of boredom or for sensory enjoyment. Grass-eating is usually harmless, but excessive grazing combined with vomiting or diarrhea could indicate an underlying issue, like gastrointestinal distress.
Dogs Feel Guilty When They Look “Ashamed”

That “guilty” look—ears back, head lowered, and wide eyes—isn’t an admission of wrongdoing. Instead, it’s a submissive response to your tone, body language, or scolding. Dogs don’t associate their past actions with your current anger; they’re simply reacting to your behavior at the moment.
You Can’t Teach an Old Dog New Tricks

Older dogs can also learn new skills, and training them can also improve their mental and physical health. While puppies may pick up commands faster due to their youthful energy, older dogs often have better focus and patience. Whether it’s basic obedience, fun tricks, or even agility exercises, teaching an older dog can strengthen your relationship and keep them mentally sharp.
A Dog’s Mouth Is Cleaner Than a Human’s

This myth likely comes from observing dogs lick their wounds, which has mild antibacterial benefits due to enzymes in their saliva. However, a dog’s mouth contains plenty of bacteria, including harmful ones picked up from licking unclean surfaces, eating waste, or chewing on dirty objects. While dog bites are less likely to cause infections than some other animal bites, they still carry risks.
Dogs Need a Litter of Puppies Before Being Spayed

The idea that dogs should have a litter before being spayed is outdated and unfounded. Spaying before a dog’s first heat cycle significantly reduces the risk of mammary cancer and eliminates the risk of uterine infections (pyometra). Early spaying doesn’t negatively affect a dog’s personality or well-being, and it helps control pet overpopulation.
Dogs Should Be Dominated to Respect You

The dominance theory originated from flawed studies on captive wolves and has since been debunked. Dogs don’t view their human family as a “pack” in the same way wolves do. Training based on dominance can lead to fear, anxiety, and aggression. Instead, positive reinforcement—rewarding good behavior with treats, praise, or toys—builds trust and strengthens the bond between you and your dog.
Dogs Only Bark to Communicate

Barking is only one of many ways dogs communicate, and its meaning depends on context. Dogs bark to alert you to danger, seek attention, express excitement, or even out of boredom. Pay attention to the tone, frequency, and accompanying body language.
Dogs Don’t Need Dental Care

Dental health is often overlooked but is crucial to your dog’s overall well-being. Plaque buildup can cause gum disease, tooth loss, and even systemic issues like heart or kidney problems. Regular brushing, dental treats, and veterinary cleanings are essential to prevent oral health issues. Starting a dental care routine early in your dog’s life makes the process easier and more effective.
Certain Breeds Are Naturally Aggressive

Aggression isn’t tied to breed but to individual temperament, upbringing, and environment. While some breeds have traits like high energy or guarding instincts, proper training and socialization can ensure any dog becomes a well-behaved companion. Mislabeling breeds as “aggressive” often leads to unfair breed-specific legislation (BSL) that overlooks the root cause of problem behaviors.
Dogs Heal Their Wounds by Licking Them

While licking can help clean a wound initially, excessive licking can introduce bacteria or reopen wounds, leading to infections or delayed healing. This behavior, known as “lick granuloma,” can also become compulsive. For minor wounds, clean them with vet-approved solutions, and consider using an Elizabethan collar (cone) to prevent licking.
Dogs Can Be Left Alone All Day Without Issues

While pups are adaptable, leaving them alone for long periods of time can lead to separation anxiety, boredom, and destructive behaviors. If you’re away for long hours, you should think about hiring a dog walker, using puzzle toys, or asking your neighbor or pet sitter to visit. Meeting their physical and emotional needs ensures a happier, healthier dog.