P‐79 Hair follicle growth arrest in Austrian Icelandic horses

Abstract

In February 2003, 20 of 70 Icelandic horses were referred with winter seasonal recurrent problems of circumscribed hair loss and scaling on the ear base, temporal eye canthus, dorsal neck and, occasionally, the cranial shoulder, with only minimal pruritus. Health status was otherwise normal. Diagnostic therapy for dermatophytes and ectoparasites had only been of minimal success. The first onset of disease was in November 2001 after relocation of the healthy herd from southern Austria. Skin problems remained until hair shedding was completed in May/June 2002 and were absent from then until November 2002. The horses were otherwise healthy and did not suffer from allergic dermatitis in summer. The herd was fed hay and grass silage exclusively. Most affected horses were young stallions and mares. Vaccination and deworming status was current. Skin scrapings and culture for bacteria and dermatophytes were negative. Apart from a nonspecific, very mild dermatitis, histopathology yielded catagenization of hair follicles going into growth arrest. Except for a slight lymphocytosis, blood analysis was normal in all affected horses. Feedstuff analysis of the hay and grass silage was normal for minerals and the trace elements Cu and Zn, and serum levels of Ca, Cu, Zn, Fe and Mn were within normal limits. Feed supplementation with vitamins, iodine, cobalt and selenium (Super‐Mineral) since spring/summer 2003 was able to prevent the development of hair follicle growth arrest in the affected horses during the winter period of 2003. Funding: Self‐funded.