Page 416 - The Veterinary Care of the Horse

Septic or infectious tenosynovitis

Infection of a tendon sheath is a serious medical emergency. The digital flexor tendon sheath
VetBooks.ir (DFTS) is the most susceptible to injury and the condition is described here.

CAUSES

• The commonest route of infection is through a puncture wound or laceration at the back
of the pastern. This may be caused by a thorn or other sharp object.

• It may occur following an injection into the DFTS.

• Occasionally infection my spread in the bloodstream to the tendon sheath from an
abscess or infection elsewhere in the body.

CLINICAL SIGNS

These include:
• sudden onset severe lameness

• the horse may stand with its heel raised from the ground

• on occasions these wounds cause such extreme pain that the horse will not bear weight

on the limb
• swelling of the tendon sheath; this may be masked due to a generalized and severe

cellulitis of the fetlock and pastern regions
• the wound may be open and leak synovial fluid; small puncture wounds, however, can

easily be overlooked if they seal up quickly

• the horse may have a temperature, increased respiratory rate and tremble.

DIAGNOSIS

Prompt diagnosis is essential otherwise inflammatory enzymes can damage the tendon within

the sheath and the fibrin produced causes adhesions to develop. Diagnosis is made on:
• the clinical signs

• analysis and culture of synovial fluid taken from the tendon sheath (Figures 9.6a and b);

infected synovial fluid has a higher protein and white cell count than normal
• ultrasonography

• radiographs may be taken to rule out damage to underlying bone.