The tendon sheath is the balloon like structure that encloses and lubricates the flexor tendons slightly above and below the fetlock joint. The digital flexor tendon sheath is present on both front and hind limbs on the rear of the fetlock joint. See the accompanying photo for the location of the normal tendon sheath.
A septic (infected) tendon sheath usually results from a wound that has penetrated into the sheath, most often on the rear of the pastern. Bacteria are introduced into the sheath and proliferate, and a massive inflammatory process follows. More rarely, infection can be introduced during veterinary injection of the tendon sheath. Very rarely (more commonly in foals), bacteria can arrive in the tendon sheath via transport in the blood.
As with any infected synovial (joint or tendon sheath) structure, infection causes severe lameness and swelling and is a life threatening problem. As long as there is a wide open wound and significant drainage, lameness is not as severe. Once the wound heals closed, the tendon sheath becomes a closed “abscess” and the horse is severely lame.
Other Diagnoses Considered
Treatments May Include
Prognosis & Relevant Factors
Fair to guarded with aggressive treatment. Grave without appropriate treatment.
I Might ObserveRelated Observations
QUESTIONS TO ASK MY VET