Osteoarthritis (OA) of the distal tarsal joints is one of the most common causes of hindlimb lameness in the horse . Diagnosis is made by a combination of procedures, which include physical and lameness examinations, diagnostic analgesia and radiography . Nuclear scintigraphic evaluation may be useful in certain cases. Magnetic resonance imaging and histology have also been used to further characterise the pathological processes and changes associated with this condition [3–5].
In spite of significant diagnostic advances, treatment options available to the general practitioner are still limited. Those available can be divided into nonsurgical and surgical . Nonsurgical treatments involve systemic and local medication, which, combined with exercise management, attempt to reduce inflammation and pain . Surgical options include procedures aiming to stimulate ankylosis of the small tarsal joints [7,8], to desensitise the area by tibial neurectomy  or to reduce pressure on the tarsus by cunean tenectomy . Several methods of stimulating ankylosis by physical or chemical cartilage destruction have been described. These include drilling across the joint surfaces, with or without additional internal fixation, the use of a laser and controlled injection of monoiodoacetate (MIA) . Results from the use of MIA vary greatly between studies [8,11] and up to 3 injections may be required to achieve ankylosis .
Recently, Shoemaker et al. , described the effects of intra-articular infiltration of ethanol into the tarsometatarsal joints of sound horses. Importantly, this report described histological evidence of ankylosis 12 months after injection and reported no associated significant complications or discomfort. The results of its use in 11 clinical cases of distal tarsal OA were reported in 2009 with 100% success for reduction in lameness at 12 months  and, in a separate study, 16 of 16 horses demonstrated short to medium term improvement .
The authors have used ethanol since 2007 as a treatment for distal tarsal joint OA in cases that failed or ceased to respond to intra-articular corticosteroids. Our aims in this study were: 1) to evaluate the clinical response to treatment with intra-articular ethanol in horses that had received and not responded satisfactorily to intra-articular corticosteroid treatment; and 2) to describe and critically analyse the technique of tarsometatarsal joint (TMTJ) intra-articular treatment with ethanol. To our knowledge this is the largest published report on the effects of this treatment in clinical cases of distal tarsal joint OA to date.