Long Hair 1

The length of the hair covering both the body and the limbs and tail of the dog has been related to a single gene, called FGF5.

Definition

The trait refers to the variant causing long hair on the body, legs and tail. The variant is in the FGF5 gene, which is involved in the regulation of hair growth in the hair follicle.

Genetic basis

The variant is recessive, therefore the long silky coat will only be expressed in dogs with two copies of the c.578C>T variant. In the case of a single copy of the c.578C>T variant or none at all, the dog is likely to show a short coat length. However, several variants have been identified in the FGF5 gene which, when combined with this variant in compound heterozygosis (one copy of each variant), could also generate a phenotype characterised by a longer coat.

Other relevant information

Long hair in dogs can be described as fluffy (in Corgi) or shaggy coat. It is believed that the long hair comes from ancestral wolves, which had a long coat that acted as a thermal insulator in cold climates. Long-haired dogs require more thorough maintenance of their coat. Brushing, bathing and trimming are important to avoid the development of tangles that can cause discomfort and even skin lesions. In fact, long hair can be straight or curly and fine or coarse, so some breeds will require more maintenance than others. The breeds that commonly present this variant are Akita and Samoyed.

Bibliography

Cadieu E, Neff MW, Quignon P,et al. Coat variation in the domestic dog is governed by variants in three genes. Science. 2009 Oct 2;326(5949):150-3."

Dierks C, Mömke S, Philipp U,et al. Allelic heterogeneity of FGF5 mutations causes the long-hair phenotype in dogs. Anim Genet. 2013 Aug;44(4):425-31.