The Hair Follicle: A Comparative Review of Canine Hair Follicle Anatomy and Physiology

Toxicol Pathol. 2016 Jun;44(4):564-74. doi: 10.1177/0192623316631843. Epub 2016 Mar 21.

Abstract

The hair follicle (HF) has a wide range of functions including thermoregulation, physical and immunological protection against external insults, sensory perception, social interactions, and camouflage. One of the most characteristic features of HFs is that they self-renew during hair cycle (HC) throughout the entire life of an individual to continuously produce new hair. HC disturbances are common in humans and comparable to some alopecic disorders in dogs. A normal HC is maintained by follicular stem cells (SCs), which are predominately found in an area known as the bulge. Due to similar morphological characteristics of the human and canine bulge area, the particularity of compound HFs in humans and dogs as well as similarities in follicular biomarker expression, the dog might be a promising model to study human HC and SC disorders. In this review, we give an overview of normal follicular anatomy, the HC, and follicular SCs and discuss the possible pathogenetic mechanisms of noninflammatory alopecia.

Keywords: alopecia; canine; follicular anatomy; follicular stem cells; hair cycle; hair follicles; pathogenesis.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Dogs
  • Hair Follicle / anatomy & histology*
  • Hair Follicle / physiology*
  • Humans