Currently, there are about 400 breeds of dogs in the world. Among them there are breeds that are spread all over the globe and have a huge number of individuals, such as the German shepherd. Others are counted in tens of individuals or have a very narrow distribution, such as Shar Pei, Irish wolfhound or Mexican naked. Some breeds are known only within the countries where they were bred. These include the Stablehun in the Netherlands, the Norbettenhund in northern Norway, and the Slovak dude in the Czech Republic and Slovakia.
There is no uniform systematization of breeds of dogs yet. This is due to the fact that not all dog breeds are represented in all countries and that most breeds of dogs are common only in their countries of origin and in the countries adjacent to them. Only about one fourth of all breeds are more or less found in most countries, i.e. almost all over the globe. Therefore, in a number of countries the majority of breeds are not known at all, and some of them we get acquainted with only at international exhibitions.
Fashion and popularity often play a big role in the spread of breeds. Then the number of dogs of this breed sharply increases to give way in a few years to a new fashionable, becoming a popular breed. This emergence of new fashionable breeds in many ways contributes to their significant spread. However, it is not always possible to assert that the fashionability of the breed serves it well. Commercial, conjuncture reasons bring the breed down to a low level, if the dog-breeding organizations of the breed do not take enough energetic measures to include only typical individuals in the breeding and to ensure that the selection of parent pairs, regardless of demand, strictly obeyed the basic requirements of selection.
At present, we are witnessing a certain reduction of large breeds, which are replaced by small, short-legged ones. This is due to various reasons. In cities where the population is concentrated in multi-storey buildings in new housing areas and where there are often difficulties with food, small dogs are more comfortable, they do not need more space for their motions, they are easier to transport out of town and, finally, they consume less food. This is not related to the risk of extinction of large breeds, but only contributes to the relocation of their breeding and maintenance to rural areas. In these new conditions, the breeding of large dogs will be more promising, as they cannot be replaced by small, short-breed breeds for domestic use.
From the above observations it is clear that as soon as the breeding of some breed becomes an end in itself, and its existence is not conditioned by social necessity, it disappears. It will take its place in another, more necessary and useful, and therefore more viable breed.
At classification of breeds in the domestic literature breeds are divided into three groups: hunting, sports and service and decorative.
Hunters are divided into hounds, hounds by blood trail, greyhounds (pursued by sight), cops and setters (hunting birds), spaniels (hunting waterfowl and bushes), retriever (bringing shot game), hunting terriers (burrow), hunting stalls (hunting fur-bearing animals).
Service-sports – shepherds (sheepdogs, dog-like, likes), watchtowers (dog-like, spitzers, pinchers and schnauzers), riding likes.
Decorative – terriers (made for battles), decorative terriers, spaniels, pinchers, western and eastern decorative dogs, some dogs (Shar Pei, English and French Bulldogs, Pug), Dalmatian, Poodles.
We can give another classification based on the purpose for which the dog is used.
Hunting – used only for hunting, not suitable for sports and companions because of a strong hunting instinct (Jagdterrier).
Hunting and sporting dogs are suitable for both hunting and sport, they can be good companions, they can be used in certain services (e.g., for searching for drugs) (Labrador retriever, English Cocker Spaniel).
Service – used only on any services, are not suitable neither for companions nor for sports, mainly because of increased aggressiveness to people (Caucasian, Central Asian shepherds).
Sports and service – can be used at various special services and for sports, as well as as companions (Rottweiler, Airedale Terrier, Collie).
Sports and decorative – ornamental dogs, which can be used as companions and for participation in competitions (Poodle, Shelty).
Room-decorative dogs – dogs that need home maintenance and caring care are unlikely to be suitable for sports competitions and as companions (English Bulldog).
The size of the breed is divided by:
Very small dogs. Less than 30 cm tall. Weight less than 5 kg.
Small dogs. Height 30-40 cm. Weight 5 – 10 kg.
Medium dogs. The height of 40-56 cm. Weight 10-20 kg.
Big dogs. Height 56 – 65 cm. Weight 20-30 kg.
Very large dogs. Height 65 – 75 cm. Weight 30-50 kg.
Giant dogs. Height over 75 cm. Weight over 50 kg.
It should be remembered that these groups, with rare exceptions, are not isolated from each other. Only the oldest breeds have a certain purity of origin.