Canine noninflammatory alopecia: An approach to its classification and a diagnostic aid

Abstract

Noninflammatory alopecia is common in dogs and is a frequent cause to consult a veterinarian. It is also a common reason to take biopsies. Noninflammatory alopecia can be attributed to a decreased formation or cytodifferentiation of the hair follicle or the hair shaft in utero, resulting in congenital alopecia. Congenital alopecia often has a hereditary cause, and examples of such disorders are ectodermal dysplasias associated with gene variants of the ectodysplasin A gene. Noninflammatory alopecia may also be caused by impaired postnatal regeneration of hair follicles or shafts. Such disorders may have a clear breed predilection, and alopecia starts early in life. A hereditary background is suspected in those cases but has not been proven. They are referred to as follicular dysplasia although some of these disorders present histologically like a hair cycle disturbance. Late-onset alopecia is usually acquired and may be associated with endocrinopathies. Other possible causes are impaired vascular perfusion or stress. As the hair follicle has limited possible responses to altered regulation, and histopathology may change during the course of a disease, a detailed clinical history, thorough clinical examination including blood work, appropriate biopsy site selection, and detailed histological findings need to be combined to achieve a final diagnosis. This review aims to provide an overview about the known noninflammatory alopecic disorders in dogs. As the pathogenesis of most disorders is unknown, some statements are based on comparative aspects or reflect the authors’ opinion.

Comparison between melatonin versus melatonin and photobiomodulation versus photobiomodulation in the treatment of Alopecia X in German Spitz dogs: Clinical, randomized, double-blind, parallel, non-inferiority protocol

“…Alopecia X is a non-inflammatory hair loss disorder of plush coated dogs that mainly occurs in male German and Italian Spitz breeds. In Spitz breed, the disease accounts for nearly 23% of all non-inflammatory hair loss disorders [ 1 ]. Alopecia X is a poorly understood skin disorder featuring symmetrical truncal, cervical, perineal, and/or caudal aspects of the hindlimbs, hair loss, and/or skin hyperpigmentation with no pruritus or systemic signs [ 2 ].…”