Hair Cycle and Alopecia X in Dogs

January 2008 in “ Pratique médicale & chirurgicale de l'animal de compagnie ”

N. Cochet-Faivre, Pascal Prélaud, F. Degorce‐Rubiales

Alopecia X hair cycle arrest hormone receptors hair follicle flame follicles trichilemmal keratinization castration melatonin trilostane steroid hormone levels hair loss hair regrowth

Studysummary This review discusses the controversial non-inflammatory alopecia known as alopecia X, highlighting its unknown etiology and the variable effectiveness of various proposed treatments, but reports no new results. Our plain-language summary of this paper — not a Tressless recommendation.

The document reviewed Alopecia X in dogs, a non-inflammatory, symmetrical hair loss condition with unknown etiology, primarily affecting breeds like Pomeranians and miniature poodles. It suggested that the condition might involve hair cycle arrest due to abnormalities in hormone receptors at the hair follicle level. Histopathology often showed "flame follicles" and excessive trichilemmal keratinization. Various treatments, including castration, melatonin, and trilostane, had variable efficacy, with no significant changes in steroid hormone levels before and after treatment, indicating hair regrowth was not due to hormonal modifications. The study concluded that Alopecia X is not a true endocrinopathy and recommended avoiding potentially harmful treatments for this primarily aesthetic issue.

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13 / 13 results

research Estrogen Receptor Antagonist and Hair Regrowth in Dogs with Hair Cycle Arrest (Alopecia X)

11 citations , January 2007 in “Veterinary dermatology”

This study found that administerating 10 mg/kg intramuscular fulvestrant did not stimulate hair regrowth in Pomeranian dogs with alopecia X, though higher doses may warrant further investigation.

research Update on Drugs Used to Treat Endocrine Diseases in Small Animals

20 citations , September 2006 in “The Veterinary clinics of North America. Small animal practice/Veterinary clinics of North America. Small animal practice”

This article reviews new drug therapies for endocrine disorders, discussing specific treatments such as trilostane for hyperadrenocorticism and various insulins for diabetes mellitus, but it reports no new clinical findings.

research Estrogen Receptor Evaluation in Pomeranian Dogs with Hair Cycle Arrest (Alopecia X) on Melatonin Supplementation

20 citations , July 2006 in “Veterinary dermatology”

This study found that hair regrowth in Pomeranians with hair cycle arrest treated with melatonin was not associated with a change in oestrogen receptor-α staining.

research The Use of Trilostane for the Treatment of Alopecia X in Alaskan Malamutes

15 citations , September 2005 in “The Journal of the American Animal Hospital Association/Journal of the American Animal Hospital Association”

This study found that trilostane treatment led to complete hair regrowth in three Alaskan malamutes with ACTH-stimulated elevated 17-hydroxyprogesterone levels within 6 months without any recognized adverse effects.

The Role of Melatonin in Neuroectodermal-Mesodermal Interactions: The Hair Follicle Synthesizes Melatonin and Expresses Functional Melatonin Receptors

research The Role of Melatonin in Neuroectodermal-Mesodermal Interactions: The Hair Follicle Synthesizes Melatonin and Expresses Functional Melatonin Receptors

122 citations , July 2005 in “The FASEB journal”

This study found that hair follicles in both mice and humans may serve as an important site for melatonin synthesis and signaling, potentially influencing hair cycle regulation by modulating keratinocyte apoptosis.

research In Vitro Metabolism of Progesterone by Canine Hair Follicle Cells

11 citations , June 2005 in “Veterinary Dermatology”

In this study, dermal fibroblasts in the head of beagle dogs metabolized the highest amount of progesterone, primarily into cortisol, while dermal papilla cells mainly produced 5α-pregnane-3,20-dione and cortisol.

research Growth Hormone-Responsive Alopecia in Dogs

21 citations , May 2005 in “Journal of the American Veterinary Medical Association”

The exact cause of growth hormone-responsive alopecia in dogs is unclear.

research Apoptotic Cell Death in Canine Hair Follicle

5 citations , January 2005 in “PubMed”

In this study, researchers observed that apoptosis occurs in both growing and regressing hair follicles in dogs, indicating a spatio-temporal relationship with the hair cycle.

research Clinicopathologic and Morphologic Analysis of the Adrenal Gland in Pomeranians with Non-Illness Alopecia

2 citations , January 2005 in “The Japanese Journal of Veterinary Dermatology”

In this study, Pomeranians with non-illness, generalized alopecia did not exhibit adrenal or pituitary abnormalities, suggesting a breed-specific hormonal pattern as a potential cause rather than a functional adrenal anomaly.

research Treatment of Canine Alopecia X with Trilostane

40 citations , October 2004 in “Veterinary Dermatology”

In this study, trilostane treatment led to complete hair re-growth in 85% of Pomeranians and all miniature poodles with alopecia X within 4 to 8 weeks.

Adrenal Steroid Hormone Concentrations in Dogs with Hair Cycle Arrest (Alopecia X) Before and During Treatment with Melatonin and Mitotane

research Adrenal Steroid Hormone Concentrations in Dogs with Hair Cycle Arrest (Alopecia X) Before and During Treatment with Melatonin and Mitotane

52 citations , October 2004 in “Veterinary dermatology”

This study found that 62% of neutered dogs with hair cycle arrest experienced partial to complete hair re-growth after melatonin treatment, but hair re-growth was not consistently linked to normal sex hormone levels.

research Retrospective Evaluation of Sex Hormones and Steroid Hormone Intermediates in Dogs with Alopecia

34 citations , March 2003 in “Veterinary Dermatology”

This study found that in dogs with alopecia, certain steroid hormone levels were elevated, particularly progesterone, but not all hormone abnormalities were consistent across breeds, suggesting the need for breed-specific evaluation.

research Growth of Secondary Hair Follicles of the Cashmere Goat In Vitro and Their Response to Prolactin and Melatonin

56 citations , August 1994 in “PubMed”

This study found that prolactin and melatonin both stimulated hair shaft elongation in Cashmere goat hair follicles, with maximum growth observed at specific concentrations, although melatonin reduced follicle viability after 96 hours.