Document Detail

Comparison of hair follicle histology between horses with pituitary pars intermedia dysfunction and excessive hair growth and normal aged horses.
MedLine Citation:
PMID:  23331700     Owner:  NLM     Status:  In-Data-Review    
Background -  Pituitary pars intermedia dysfunction (PPID) in older equids is commonly recognized by a long hair coat that fails to shed. Objective -  The aim of this study was to compare hair follicle stages in PPID-affected horses with excessively long hair coats with the stages of normal aged horses (controls) and to compare hair follicle stages in PPID-affected horses after 6 months of treatment with pergolide mesylate with those of control horses. Animals -  Eight PPID-affected horses and four normal, age-matched, control horses. Methods -  Skin biopsies were collected from the neck and rump of PPID-affected and control horses. A diagnosis of PPID was established based on hair coat changes and supportive overnight dexamethasone suppression test results. Skin biopsies were repeated after 6 months of treatment with pergolide. The number of hair follicles in anagen (A) or telogen (T) was counted for each skin biopsy using transverse sections. Results -  Pretreatment biopsies had a greater percentage of A follicles (neck 96%, rump 95%) and a lower percentage of T follicles (neck 4%, rump 5%) in PPID-affected horses than in control horses (A, neck 15%, rump 25%; and T, neck 85%, rump 75%). After treatment with pergolide, all PPID-affected horses had improved shedding, and the percentages of A follicles (neck 69%, rump 70%) and T follicles (neck 31%, rump 30%) were not different from untreated control horses (A, neck 68%, rump 82%; and T, neck 32%, rump 18%). Conclusions -  These findings document that excessive hair growth (hypertrichosis) in PPID-affected horses is due to persistence of hair follicles in A. Furthermore, treatment with pergolide improved shedding and reduced the percentage of A follicles in PPID-affected horses.
Marie Innerå; Annette D Petersen; Danielle R Desjardins; Barbara A Steficek; Edmund J Rosser; Harold C Schott
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Veterinary dermatology     Volume:  24     ISSN:  1365-3164     ISO Abbreviation:  Vet. Dermatol.     Publication Date:  2013 Feb 
Date Detail:
Created Date:  2013-01-21     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9426187     Medline TA:  Vet Dermatol     Country:  England    
Other Details:
Languages:  eng     Pagination:  212-e47     Citation Subset:  IM    
Copyright Information:
© 2013 The Authors. Veterinary Dermatology © 2013 ESVD and ACVD.
Department of Small Animal Clinical Sciences, Diagnostic Center for Population and Animal Health and Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Canine inflamed nonepitheliotropic cutaneous T-cell lymphoma: a diagnostic conundrum.
Next Document:  Equine sarcoidosis: clinical signs, diagnosis, treatment and outcome of 22 cases.