The dog (Canis lupus familiaris) is a mammal of the canine family that was domesticated around 14 000 to 15 000 years ago. Currently, there are about 400 breeds of dog, which differ from each other in both appearance and character. The size of a dog can vary from a dozen centimetres (e.g. Chihuahua) to almost a metre tall (e.g. Great Dane). There is also a surprising variety of coat colours and shades, ranging from white to black, and various shades of brown and grey.
Dogs are adaptable and therefore well-liked by people – they are easy to train, playful and can be useful in a variety of support roles. Some breeds of dogs are excellent helpers in hunting, herding cattle, assisting rescue workers, policemen and as companions for the blind.
The Story of Domestication
The dog is one of the oldest domesticated animals. Archaeologists have discovered dog paintings dating back some 10,000 years on rocks in what is now Turkey and North America, and have concluded that dogs are the most ancient of all human animals.Dogs are thought to have been domesticated as early as the middle of the Stone Age. But there is no consensus.
Swedish geneticist P. Savolainen, who has analysed the DNA of 654 different dog breeds from different continents, believes that the dog originated in human life around 15 000 years ago in East Asia. American biologist R. Vein says it was at least 40 000 years ago. Dogs were first bred for meat, then their hunting abilities were discovered, and later they were used to protect territory.
The Quill
The origin of dogs is still the subject of many hypotheses. However, there is almost unanimous agreement that the ancestor of the modern dog was the wolf and some species of jackal. The scientific debate on the origin of dogs can be divided into two main groups: some believe that dogs are descended from several different ancestors, others that dogs are descended from a single ancestor species.The descent of the dog from the wolf is supported by the results of various studies – chromosomal, behavioural, vocalisation, genetic comparison.
dog breed groups
The FCI recognises 337 dog breeds.These breeds are divided into 10 groups according to their purpose:
- Shepherd Dogs (Sheepdogs, Shepherd Dogs, Cattle Guard Dogs);
- Pinschers, Schnauzers, Molossians, Mastiffs and Swiss Zennenshunds;
- Terriers (long-legged terriers, short-legged terriers, bulldog terriers, dwarf terriers, black terriers);
- Dachshunds;
- Spitz (Arctic and sled dogs, Scandinavian guardian spitz, European spitz, primitive spitz);
- Scalics;
- Pointers (European Pointers, French Brackens, Setters and Pointers);
- Spaniels and Retrievers (Retrievers, Spaniels, Water Dogs);
- Companion dogs (Bichons, Poodles, Belgian Griffons, Hairless Dogs, Tibetan Dogs, Chihuahuas, English Dwarf Spaniels, Japanese Chin and Pekingese, European Dwarf Spaniels, Dwarf Mastiffs);
- Greyhounds (long-haired, rough-haired, smooth-haired).
Physical characteristics of dogs
Height. Dogs range in height from 100 cm (Great Dane) to 15 cm (Chihuahua).
Weight: different breeds of adult dogs can range in weight from around 2 kg (Chihuahua) to 70 kg or more (Saint Bernard).
Coat. Depending on the breed, the length of the dog’s coat varies from almost no fur at all (e.g. Mexican Hairless Dog) to a hair that reaches 55 cm in length.
The coat of different breeds also varies in terms of coat characteristics, with some breeds having a coarse coat and others having a fine coat. A long and luxuriant coat protects the dog from the cold. The density of a dog’s coat also depends on the air temperature – the coat becomes denser when it is cold.
It is commonly believed that dog fur causes allergies in allergy sufferers. In fact, this is not the case. The main source of allergies is the proteins found in dog saliva and dander.
Ears. The shape of the ears of some breeds is very different from the erect and sharp ears of their ancestral wolves, with some breeds having shorter ears and others having much longer ears, up to 100 cm long (e.g. the Foxhound).
Ears are sometimes cropped at an early age to give a steep and sharp shapes.
Oodega. There are many variations of tail shapes. Some breeds do not have a single tail variant, so several variants are bred.
Paws. All dogs have 4 toes on each paw. Each toe has a claw. The claws, unlike those of cats, do not retract inwards. On the inside of the front paw there is a fifth toe. Depending on the breed, this toe may be high on the paw and poorly developed, useless or well developed.
Teeth. Like all mammals, dogs grow milk teeth and then permanent teeth. Small, sharp milk teeth develop by 6 to 8 weeks of age in puppies. Around week 14, the permanent teeth fall out and begin to erupt. At five months of age, the puppy has all 42 permanent teeth, 22 in the lower jaw and 20 in the upper jaw.
Sweat glands. Dogs have large sweat glands all over the body, which secrete a rather thick, milk-like, smelly sweat. The sweat mixes withwith sebaceous gland secretions, thus forming a natural fatty ointment for the skin and coat. Sweating increases when an animal becomes ill and the body tries to remove the toxic substances accumulated during the illness as quickly as possible. As a result, a dog’s perspiration can provide information about its state of health.
Voice. Dogs can make sounds of varying pitch and intensity. For example, a lost dog moans when it is in pain, whines when it is eating and growls when it is eating. However, the most common sound a dog makes is barking. All dog breeds are capable of singing, i.e. dogs react to sounds of a certain frequency and bark in response to the tone.
Lifespan. Lives up to 10 – 16 years, sometimes longer.
Sex. Males tend to be larger than females.
Reproduction. A litter of 4 – 5 pups is usually produced. Females have a well-developed instinct for caring for their pups and may fight to the death to protect and defend them. Males do not have this instinct and react indifferently, or in exceptional cases hostilely, to the pups.
Manythe hatching period. Most varieties can reproduce every 6 months.
Sexual maturity. Puppies mature between 6 and 12 months.
Pregnancy. Gestation is 9 weeks.
Pups. Pups are born blind, deaf and completely helpless. However, they have an excellent sense of smell and can easily find their mother’s nipples.
Food. Eats both animal and plant foods. Animal food is more common.
Sleep. Although dogs are used to living with humans, specific behavioural traits of their wolf ancestors have been preserved. dogs can be active both during the day and at night. dogs can go for many days without food or water, but sleep is essential. if a dog goes without sleep for several days, it may die. Dogs are deeply asleep, can snore and dream, but wake up instantly if necessary.
Damage
Hearing. Hearing is highly developed. a dog can hear up to 40,000 hertz, while a human can hear up to 20,000 hertz. Thus, dogs can hear ultrasound. Dogs are good at distinguishing between musical sounds – consonances and dissonances.
Oosl. The sense of smell varies greatly depending on the breed of dog, but it is still far superior to the human ability to smell odours. Some dogs can smell faint scents that cannot be detected by any instrument, e.g. they can pick out the scent of a particular person from hundreds of people. This distinguishes dogs from other animals.
Taste. The sense of taste has not been extensively studied scientifically, but it is thought to be stronger than in humans. It is difficult to determine how much of this is due to the sense of smell.
Taste. A dog’s visual spectrum is smaller than that of a human. It sees colour, but cannot distinguish between red and orange. It can distinguish as many as 40 shades of grey. Dogs’ entire visual spectrum is shifted towards ultraviolet colours.
Glitter. The sense of touch is less developed than in humans.
varieties
Habitat. Lives both in the wild and in human habitation.
Enemies. Stray dogs are killed by humans, other dogs, wolves, jackals, and other large predators.
Social structure. In the wild, they live both singly and in small groups. Mating