Classification of dogs by coat characteristics

Dog fur is an important skin derivative that protects dogs from adverse environmental effects and keeps their body temperature constant. The shape and color of the coat is an important characteristic of the breed, and a gorgeous coat is the second life of many pet dogs.

The dog's coat consists of coat, down and trim. The coat is also called upper hair, which is the main part of dog hair color. Generally, the hair is long and thick, and the pith hair accounts for the majority, which mainly plays the role of heat preservation. Ornamental hair refers to hair that is born on the ears, tail, and lower limbs. According to the length of the coat, dogs are generally divided into short-haired dogs, hairless dogs, long-haired dogs and silky dogs.

(1) Short-haired dogs: such as Shard, Greyhound, Boxer, Great Dane, Dalmatian, Egyptian hound, etc. The short hair character of dog coat is controlled by dominant gene L. Dogs homozygous for gene L show short hair character in the first generation when mated with long-haired dogs, and the character segregation occurs in the second generation, that is, a small number of long-haired dogs are produced.

(2) Hairless dogs: In general, hairless dogs are limited to deformed offspring, but some dogs have this characteristic, such as Chinese Crested Dogs and Mexican Hairless Dogs. These two breeds are not normally completely hairless, but have hair only on the head, lower limbs, and tail. After research, hairless character is controlled by dominant H gene, this gene is homozygous lethal, so all living hairless dogs have heterozygote Hh, its genetic law has sex-linked genetic characteristics, and most of the living hairless dogs are female, Chinese crested dogs have a history of more than 400 years, also known as "Chinese naked dogs". The average weight is 5.5 kg, the body height is 23-30 cm, the appearance looks like an Italian greyhound, the skin is pink or white, smooth, soft, without wrinkles. The Mexican Hairless Dog is similar in size to the Chinese Crested Dog and comes in two types. The larger ones are almost exclusively restricted to Mexico, where reproduction is strictly controlled by scholars, weighing 11-16 kg and 40-51 cm tall; the smaller ones are distributed outside Mexico, smaller and more elegant.

(3) Long-haired dogs: such as straight-haired German shepherds, open-haired Rhodesian ridgebacks, curly-haired English setters and cocker spaniels, hairy old-fashioned English shepherds, bristle-type Arete dogs, etc.

Long hair is controlled by the long hair gene e, which is recessive inheritance, that is, this pair of genes only show long hair characteristics when homozygous. The expression of gene e is affected by many factors, resulting in many different morphological characteristics of long hair types. Some dog hair is not very long, flat spread on the body, limbs and tail, showing long hair characteristics, such as the English set dog; some dog hair is more and more dense, such as the lion dog; some dog hair is long and more, and thick fluffy, such as the old English shepherd dog; some dog hair is long and has a wavy structure, such as cocker spaniel, poodle, etc.; some dog hair is not very long, but other parts of the hair are very long, such as pekingese, Scottish shepherd dog; Shetland collie, pomeranian. Japanese breed, butterfly dog, etc.; some dogs have both long and short hair, such as dachshund. Chihuahua, Saint Bernard, etc.

(4) Silky dog: There are many long-haired dogs in the world with soft hair like silk, such as Japanese breed, Malta dog, butterfly dog, etc.