dog (Canis lupus familiaris) also called domestic dog o can, and colloquially pooch or tuso in Spain and choco In Argentina, people mainly use dogs to protect hunters and areas of the land.

It is believed that dogs were first domesticated in East Asia thousands of years ago, from a subspecies of the gray wolf that has been domesticated until today, it is very common in homes as pets (competing with cats) and they are considered as a member of the family.

Dog breeds

Today, there are more than 800 breeds of domestic dogs around the world. Mountain dogs such as Saint Bernados or Huskies and territorial guard dogs such as Neapolitan and Tibetan Mastiffs are included.

The current breeds of dogs show a variation in size, appearance and behavior than any other domestic animal where the variation between breeds is very similar.

Different breeds of dog walking

Different breeds of dog walking

Más populares

List of the world's most popular dog breeds.

  • Affenpinscher
  • Airedale Terrier
  • Akbash
  • Akita
  • Alaskan Malamute
  • American Staffordshire Terrier
  • American Water Spaniel
  • Anatolian Shepherd Dog
  • Turkish Angora
  • Old english shepherd is
  • Australian Mist
  • Basenji
  • Basset hound
  • Beagle
  • Bedlington terrier
  • Mountain bernese
  • Bichon bolognese
  • Bichon Frisé
  • Havanese
  • Maltese bichon
  • Blue Lacy
  • Bluetick Coonhound
  • Border Collie
  • Border Terrier
  • Norwegian Forest
  • Boston terrier
  • German boxer
  • Appenzeller Mountain Dog
  • Boyero de Entlebuch
  • Boykin Spaniel
  • Bull terrier
  • Bulldog
  • American Bulldog
  • French bulldog
  • Bullmastiff
  • Cairn terrier
  • Caniche
  • Serra da Estrela Dog
  • Cavalier King Charles Spaniel
  • English-American raccoon hunter
  • Cesky Fousek
  • Chantilly-Tiffany
  • Chihuahua
  • Chinook
  • Chow Chow
  • Clumber spaniel
  • Smooth hair collector
  • Cocker spaniel
  • American cocker spaniel
  • Collie
  • Bearded Collie
  • Pembroke Welsh Corgi
  • Crestado Chino
  • Dalmatian
  • Dobero
  • Argentine Dogo
  • Dogue de Bordeaux
  • Tibetan Mastiff
  • Drever
  • Dunker
  • Field Spaniel
  • Fox Terrier
  • American Foxhound
  • Golden retriever
  • Great Swiss Mountain Dog
  • Great dane
  • Harrier
  • Hokkaido
  • Siberian husky
  • Jack Russell Terrier
  • Australian Kelpie
  • Labradoodle
  • Labrador Retriever
  • Afghan Lebrel
  • Irish wolfhound
  • Maine Coon
  • English mastiff
  • Mastín napolitano
  • Egyptian Mau
  • Norfolk Terrier
  • German shepherd
  • Australian pastor
  • Australian cattle dog
  • Pekines
  • Canaan Dog
  • Carolina Dog
  • Greenland dog
  • American eskimo dog
  • American eskimo dog
  • Mongrel dog
  • English sheepdog
  • Hot dog
  • German pinscher
  • American pit bull terrier
  • Ibizan Hound
  • English pointer
  • Pug
  • Ragdoll
  • Retriever de Chesapeake
  • Curly-haired retriever
  • Rottweiler
  • Bavarian Mountain Hound
  • Bavarian blood hound
  • Saint Bernard
  • San Huberto
  • Giant Schnauzer
  • Irish setter
  • Shih Tzu
  • Snowshoe
  • Spaniel of Pont-Audemère
  • Japanese spaniel
  • Finnish Spitz
  • Springer Spaniel Inglés
  • Staffordshire Bull Terrier
  • Alpine Badger
  • Newfoundland
  • Brazilian terrier
  • Australia Terrier
  • Black Russian Terrier
  • West Highland white terrier
  • Whippet
  • Yorkshire terrier


Like many other mammals, dogs are predators and scavengers. They have powerful muscles, fused wrist bones, a cardiovascular system that supports both speed and endurance, and teeth to catch and tear. Despite being descended from the wolf, he is not as powerful as him.

They vary greatly in size and height (even within the same breed). The smallest known adult dog was a Yorkshire Terrier dog that was only 6,3 cm tall, 9,5 cm long and weighed only 113 grams. The largest known was an English Mastiff weighing 155 kg and a half 250 cm in length (from muzzle to tail) and the tallest dog was a Great Dane at 106 cm in height.


Dog teeth are specialized in biting and tearing meat. They are smaller than those of their relatives the wolves, since the dog does not need to hunt large pieces. The dog's tongue is necessary to regulate body temperature, as the moisture on the tongue instantly cools and colder air passes into the respiratory system.

The adult dog has 42 teeth (12 incesive, 4 canine, 16 premillary, and 10 molars) and the puppy has about 28 baby teeth and at four months of age he will lose his milk teeth to obtain a dog's permanent teeth. adult.


Dogs have soft pads on the underside of their legs that allow them to run quickly and quietly.

They have sharp and strong claws that help them to grip when running and also to dig. You also have dew claws on the sides of its legs to help it balance when it is running and they never really touch the ground but it also serves the dog to grab its prey.


Among the dog's senses are vision, hearing, taste, touch, smell and sensitivity to the earth's magnetic bonnet. Some studies have suggested that dogs are able to see the earth's magnetic field.


The vision of the dog was developed to hunt, it does not have visual acuities rich in details but the movements perceive them excellently. To compensate for their night vision it is also excellent and their visual field ranges from 240 - 250º which is much greater than that of humans who have 180º. And various studies have shown that a dog can see its owner from a distance of a mile.

Their perception of colors is limited, and they suffer from deuteranopia, which for humans is a type of color blindness that is affected by the poor distinction between red and green. Their vision perceives yellow and blue tones, but both red is perceived as yellow and green is seen as gray.

Among different breeds of dogs they have two types of retina. Long-nosed dogs have a "visual stripe" that runs horizontally across the retina, giving it excellent vision. Dogs with a short muzzle have a “zona centralis” which is a central region with up to 3 times more nerve endings than the visual line that provides them with a more detailed view, much like that of humans.

Although dogs are emmetropic (they have normal vision) it has been found that 1 in 2 Rottweilers are myopic.


The audibility of dogs is much more powerful than that of a human, especially when detecting bass sounds. The mobility of their ears allows them to detect the exact location of a sound and at a distance greater than that of humans, to achieve this they have 18 or more (depending on the race) muscles that can make them tilt, rotate, raise or lower them.


The brain of dogs is clearly dominated by the olfactory cortex and the olfactory bulb of dogs is forty times larger than that of humans. They have between 125 and 220 million olfactory cells deployed in an area the size of a pocket square. If we compare it with humans, we have 5 million cells spread over the area of ​​a seal. The Bloodhound dog breed possesses some 300 million olfactory cells, surpassing all dog breeds.

Thanks to this quality, dogs are used in work to locate humans, drugs, clothes ... by state authorities such as the police.


The taste is quite similar to that of humans but they do not distinguish salty, although it is not sufficiently investigated and has been closely related to smell. Like humans, when they are young they will taste all kinds of flavors and as they become adults they will develop a sense of taste. This is why from one dog to another (of the same breed) may have different preferences towards food, since apparently they do not choose food for its taste, but for its intensity: strong taste or mild taste.

It also has the ability to associate certain foods with health problems. If a food has made you sick or have a bad time, if you detect the same taste in other foods you will avoid it. This is part of a defense mechanism that protects animals from avoiding toxic food. The human being also possesses this quality.


Dogs use touch to communicate with each other and with other animal species. Done right touching the dog can stimulate or relax her. They have touch sensors all over their body, but the most sensitive areas are the bearings, the spine, and the tail area.

Like cats, dogs have vibrissae with mechanoreceptors located in the muzzle, above the eyes and under the jaw that give them tactile information about the environment around them, but it is not as important for them as it is for cats. It also helps them feel the flow of air.


Dog behavior is the response to internal and / or external stimuli. Being the oldest domesticated species ranging between 9.000 - 30.000 years BC. C the dog has been shaped over millennia by humans. The consequence of this is that the dog is the animal that is most in tune with humans and they have developed the ability to understand and communicate. These abilities are not shared by other canids, nor by more intelligent human-like species like apes, but rather parallel some of the socio-cognitive abilities of human children.

Unlike other domestic species that were selected through breeding such as cattle, the dog was selected for its behavior. In 2016 a study found that only 11 fixed genes varied between the dog and the wolf. It is not believed that this is a natural evolution if it is not the work of humans who carefully selected dogs for their morphology and behavior during their domestication. These genes have been shown to affect the fight or flight response and the emotional process, generally, dogs show less fear and aggressiveness than wolves.


Canine intelligence is the dog's ability to gather information and retain it to solve problems. Numerous studies have shown that dogs learn by inference. They have advanced memorization skills that allow them to remember what they have learned over the long term They are able to read and react to the language of the human body and understand gestures, signs and voice commands.

An experimental study showed that australian dingoes they outperform dogs when it comes to solving non-social problems. Dogs are believed to have lost some of their original abilities as they became dependent on humans.

Another study showed that once the dog is taught to solve a certain problem, if it is exposed to an insoluble problem of the same problem they will look at the human being, since the dog expects the human to solve the problem instead.


It is about the ability of dogs to "talk" to each other and to understand the messages humans send them and how humans translate what dogs are trying to convey. These behaviors include gaze, facial expressions, vocalization, body posture (including body movements and extremities), and taste communication (smells, pheromones, and tastes) Humans manage to communicate through vocalizations, hand signals, and body posture .

Dog resting

Dog resting


Due to the extreme bond that dogs and humans share, the dog population is already estimated at 900 million and grows constantly as humans do. Domesticated dogs live in their owners' home, together with humans, on farms or in gardens.

Although "the dog is man's best friend" most dogs are still wild living their lives as scavengers and have never been possessed by humans, with studies showing that 52% tend to flee or respond aggressively. Little is known about these dogs, as most studies focus on those that live with humans as pets.


Despite their descent from wolves and their qualification as carnivorous animals, some studies classify them as carnivores or omnivores. Unlike other carnivores, dogs are not strict and can adapt to a varied diet by not depending on certain proteins in meat to cover their basic protein needs. They are capable of correctly directing vegetables and grains, being able to consume them in large quantities with respect to the proportion of meat, since they also need calcium and iron that these foods do not give them.


In the domestic habitat the dog does not have any animal predators, except for the eternal fight between dogs and cats, but they do not usually grow up. However, while some dogs are safe under the safety of man, for others they are his greatest "predator." Many dogs are abused or abandoned by humans dying or roaming the streets.

Dogs that live outside the urban nucleus or in rural areas can be victims of various predators such as raptors, wolves and coyotes. These animals are skilled predators that can easily knock down a dog weighing less than 10 kg. If the dog is bigger they will try to hunt them in herd. In these areas, special attention must be paid to avoid scares.


In domesticated dogs, sexual maturity begins at 6 - 12 years for both sexes, although for large breeds it may be delayed a couple of years. At this time the females will have their first estrous cycle. They experience subsequent estrous cycles semestral, where the body prepares for pregnancy. Between this cycle, females will go into heat, being mentally and physically receptive to copulation. Bitches' eggs are capable of being fertilized after one week of ovulation, due to this it is possible that there are several parents in a litter, as in the case of cats.

Fertilization occurs 2 - 5 days after ovulation and after 14 - 16 days the embryo adheres to the uterus, the heartbeat being detectable at 7 - 8 days. Gestation lasts between 58 - 68 days with an average of 63 days. The average litter is made up of 6 puppies, although it can vary according to the breed of the dog. Small breed dogs generally have between 1 - 4 puppies while larger breeds can average up to 12 puppies.

Some breeds of dogs have obtained traits incompatible with reproduction through selective breeding. For example, male French Bulldogs are unable to impregnate the female themselves and the female must be artificially inseminated in order to reproduce.

Dog puppy

Dog puppy

State of conservation

The domestic dog is marked as Least Concern, as they are widespread throughout the world and under the care of humans.

List of other interesting animals