CLINICAL, ULTRASONOGRAPHIC, AND ARTHROSCOPIC CHARACTERISTICS OF HAIR SHAFTS WITHIN SYNOVIAL STRUCTURES OF SEVEN HORSES.

To the authors' knowledge, the ultrasonographic appearance of hair shafts within a synovial structure of the horse has not been described previously. The purpose of this descriptive study was to illustrate the clinical, ultrasonographic, and arthroscopic characteristics of confirmed hair shafts within synovial structures of seven horses. A review of medical records of the Farm and Equine Veterinary Medical Center at North Carolina State University College of Veterinary Medicine identified seven horses with clinical signs suspicious for inflammatory or septic synovitis/tenosynovitis that had hair shafts identified within those structures ultrasonographically. Imaging findings were confirmed by surgical arthroscopy, bursoscopy, tenoscopy, or necropsy. Unique ultrasound characteristics of intrasynovial hair included thin, linear, hyperechoic structures, which did not cast acoustic shadows. Findings supported the use of ultrasonography as a complementary diagnostic method for ruling out hair foreign material in horses with signs of inflammatory or septic synovitis/tenosynovitis.