Veterinarians attending the Lameness in the Sport Horse Table Topic at the 2008 American Association of Equine Practitioners convention, held Dec. 6-10 in San Diego, Calif., discussed the need for taking a complete history and performing a clinical examination before making any imaging recommendations. Imaging is only as good as the history and clinical exam that directs the clinician.

Diagnostic analgesia was discussed, with particular emphasis on the inaccuracies that are sometimes associated with some specific regional blocks. These include blocks that are routinely utilized by most veterinarians performing lameness examinations of the distal limb, such as the abaxial, low palmar/plantar, and proximal suspensory (both front and hind). In particular, MRI has helped demonstrate lesions in the fetlock joint that was effectively blocked by an abaxial nerve block. More specific analgesia techniques, such as intraarticular analgesia, can be utilized at any time during the examination.

The subject of poor performance in sport horses associated with subclinical lameness was also discussed. Veterinarians in attendance suggested performing bilateral anesthesia blocks of the front feet in horses that are not obviously lame and evaluating the results with the horse under saddle. Some of these horses improve their disposition and willingness to advance after the feet are blocked. In the case of the hind limbs it was suggested to rule out any problems distal to (below) the tarsal region. In horses that does not improve it was suggested to evaluate them at the canter. If the canter worsens or does not improve after ruling out the distal limb, the sacroiliac area becomes highly suspicious in the differential diagnosis