#01

“Dogs see in black and white”

This is the most widespread myth.

Dogs are actually dichromatic: they have two types of cones allowing them to distinguish blues and yellows, but not reds or greens.

Their world is similar to that of a person with red-green color blindness.

A red toy thrown in green grass appears grayish to them (this is not an insignificant detail when choosing their accessories).

Nose temperature and humidity fluctuate naturally depending on hydration, sleep, or activity.

A dog waking up from a nap often has a dry, warm nose yet is perfectly healthy!

Dr. Erin Ray (Texas A&M College of Veterinary Medicine) is clear: it's not a reliable indicator of illness. The element to monitor remains overall behavior and, if necessary, rectal temperature (normal: 38.3–39.2°C).

Less than 25% of dogs vomit after eating grass, and only 10% show signs of discomfort before eating it.

This behavior is observed even in wild dogs!

Probable motivations: seeking fiber, sensory exploration, or simply the taste. Sudden and compulsive consumption associated with other signs, however, warrants a consultation.

 #04

“A dog's mouth is cleaner than a human's”

That's false!

False equivalence: bacterial floras are simply different, not comparable in terms of “cleanliness”!

Canine mouths harbor specific bacteria, including Capnocytophaga canimorsus, particularly in people who are immunocompromised or have significant underlying medical conditions.

The idea of an “aseptic” mouth is a myth with no scientific basis!

Tail wagging varies depending on the direction:

In experimental settings, right-biased wagging has been associated with more positive emotional states, whereas left-biased wagging has been associated with more cautious or negative responses.

A high, stiff tail can indicate tension or an intention to aggress (or threat or other agonistic intentions).

Reading a dog solely through its tail means missing most of its body language!

No published study shows a physical or psychological benefit to having a litter before spaying!

This is an anthropomorphic projection.

Spaying before the first heat markedly reduces the risk of mammary tumours, although the optimal timing should be discussed individually with a veterinarian because recommendations vary with breed and size.

The optimal age varies by breed and sex.

This is something to discuss with your veterinarian.

This is false on a neurobiological level.

Dogs possess the same nociceptive pathways as humans (Aδ and C fibers, limbic structures).

This myth is dangerous because it leads to undertreating chronic pain, especially joint pain.

Pain is often expressed through behavioural changes rather than vocalisation.

What is true: dogs instinctively hide their pain, which often leads to late detection.

A changed behavior (withdrawal, unusual aggression, reluctance to get up) can be the only visible sign...

This is biologically inaccurate.

A study published in Cell Systems (2020) based on DNA methylation from 104 Labradors shows that a 2-year-old puppy shows DNA methylation patterns roughly comparable to a human of about 40 years old, but after that, the curve slows down...

The correlation is especially strong for major physiological milestones. For example:

8 weeks for a dog corresponds to 9 months for a human (both species begin to develop their milk teeth at this stage)

The average lifespan of a Labrador (12 years) corresponds to the global human life expectancy (70 years).

Also:

the "mature stage" corresponds to 2-7 years for dogs and 25-50 years for humans.

The "senior" stage begins around 12 years for dogs, which corresponds to 70 years for humans.

Furthermore, the aging rate varies massively depending on size:

a Great Dane is "senior" from 5 years old

a Chihuahua only around 10–12 years old

This is one of the most widespread misconceptions. And yet, the reality is more nuanced...

Size is not the determining factor.

What truly matters is the dog's energy level, behavioral needs, and individual temperament.

A Greyhound, for example, is one of the calmest dogs indoors. Large, certainly, but discreet, barks little, and is not very destructive when its needs are met.

Conversely, a Jack Russell in an apartment without sufficient outings will be more destructive than a well-exercised Saint Bernard. Small dog, big needs.

The dog's character matters as much as its breed.

Two dogs of the same breed can have very different profiles. An anxious German Shepherd will demand much more than a calm and secure one. Early socialization, the dog's history, and its individual temperament play as important a role as the characteristics of its breed.

What truly makes a difference daily:

At least 2 to 3 serious outings per day, adapted to the energy level of the breed and the individual.

Regular mental stimulation: scent games, enrichment feeding, olfactory work.

An adapted environment: non-slippery floors, easy access for large breeds prone to joint problems, especially as they age.

In summary: it's not the dog's size that determines its ability to live in an apartment. It's the consistency between its needs, its character, and its owner's lifestyle.

#11

"Mixed-breed dogs don't have health problems"

This needs to be qualified!

The idea that mixed-breed dogs are automatically healthier than purebred dogs is an oversimplification.

What is partially true: mixed-breed dogs show a lower prevalence for certain hereditary diseases specific to breeds.

Out of 24 genetic disorders analyzed, 10 are indeed more common in purebred dogs: aortic stenosis, elbow dysplasia, gastric dilatation-volvulus, epilepsy, hypothyroidism, among others.

Hybrid vigour exists, but it does not eliminate inherited disease.

What is false: believing that crossbreeding systematically protects.

Each of these 24 disorders has also been observed in the mixed-breed population.

A crossbreed between two breeds with articular risk can combine the predispositions of both parents rather than neutralizing them.

And breeds with extreme morphology, such as the Bulldog or Pug, transmit their structural problems (respiratory, orthopedic) regardless of pedigree: these are anatomical constraints, not solely genetic in the recessive sense of the term.

Crossbreeding is not a health guarantee!

It's knowing the history of both parents that matters!

This belief has been passed down for decades, yet there is no scientific evidence that having a litter provides physical or psychological benefits for female dogs.

Dogs do not experience parenthood in the same way humans do, and there is no evidence that they develop a lasting emotional need to reproduce.

On the contrary, allowing a litter exposes the female to pregnancy, whelping and potential complications, while delaying spaying may increase the risk of mammary tumours in some dogs.

The best decision depends on the individual dog, its breed, age and intended breeding programme, and should always be discussed with a veterinarian.

No scientific data shows a genetic predisposition to aggression linked to size...

What we observe is a tolerance bias: owners accept behaviors in a small dog that they would not tolerate in a large one.

A growling Chihuahua is not "in its nature"...

It simply never learned that it's not acceptable!

Coprophagia has multiple causes: atavistic behavior in puppies, boredom, anxiety, attention-seeking, etc.

In the majority of cases, no nutritional deficiency is identifiable.

In puppies, the behavior often stops spontaneously.

In adult dogs, a behavioral and dietary assessment is recommended before drawing conclusions.

Persistent coprophagia appearing suddenly in an adult dog should nevertheless be discussed with a veterinarian to rule out underlying disease.

That's wrong!

The "guilty look" is actually a calming signal in response to the owner's perceived displeasure.

Alexandra Horowitz's study (Animal Cognition, 2009) is one of the most cited: innocent dogs displayed this behavior more than "guilty" dogs when owners were convinced (sometimes wrongly) that a fault had been committed.

What you're seeing is most likely an appeasement behaviour in response to your own emotional cues, rather than guilt.