The digital flexor tendon sheath (DFTS) is an important anatomical and functional structure in the horse. Disorders of the DFTS can result in devastating consequences for the horse. During the last decade, the possibilities to diagnose and treat disorders of the DFTS have been argumented. The main purpose of this paper is to describe the technique of tenoscopy and it's applications. The aim is also to review the anatomy of the fetlock canal, the differnet types of tenosynovitis, proximal annular ligament constriction and to describe the ultrasonographic examination of the DFTS..

Septic tenosynovitis involving the digital sheath is a relatively common problem in the horse and the prognosis has been considered as poor. However, there are only few studies confirming this. The purpose of this study is to increase the knowledge about the prognosis for septic tenosynovitis in the digital sheath. The literature indicates that half or a bit more than half of the treated horses will return to previous use. The recommended treatment is debridement of the wound, lavage and sometimes application of drains and broadspectrum antibiotics. The prognosis is considered as worse when the infection is established.