How to Perform Regional Limb Perfusion in the Standing Horse

Infection of the synovial structures of the equine extremity is a common complication of lacerations and athletic injuries of the horse. Iatrogenic infection of the carpus, tarsus, metacarpal/metatarsal– phalangeal joints and distal interphalangeal joint subsequent to intra-articular injection often are career-ending or life-threatening. Regional limb perfusion by intramedullary administration of gentamicin into the radius of experimental horses under general anesthesia produced high concentrations of gentamicin within the synovial fluid of the antebrachiocarpal joint.1 Another experimental study in anesthetized horses showed that IV digital perfusion with amikacin resulted in synovial fluid concentrations 25 to 50 times the minimum inhibitory concentration required to kill most pathogenic bacteria.2 Regional limb perfusion with antibiotics that have efficacy against common equine orthopedic pathogens has been shown to be an effective adjunctive means of treatment of septic conditions of the equine extremity.3,4 In previous experimental studies and clinical reports, IV digital perfusion was performed in horses placed under general anesthesia and positioned in lateral recumbency.1–4 In one report, the authors state that intravascular perfusion can be performed in the standing horse but that the effect of weight bearing on the concentration of drug achieved is unknown.4 This report presents a practical technique for regional limb perfusion in the standing horse, eliminating the need for general anesthesia in many cases and providing a practical means of repeated follow-up treatment in horses that require anesthetic procedures for initial treatment of a septic condition.