The 12th Annual Bluegrass Laminitis Symposium, January 29 - 31, 1998
© Henry Heymering
published in ANVIL Magazine, May 1998
As always, this year's symposium was jam-packed with valuable information.
Ric Redden, DVM, started off the lectures with some tips on treatment of superficial flexor tendon (SFT) contractures, which present themselves as the fetlock knuckling forward. He says it is difficult to obtain good results, and treatment often fails. He has found that severing the SFT below the fetlock gives better results than severing it anywhere above the fetlock. It is important that the horse be shod immediately after surgery with a toe-extension and heel-extension shoe. The toe extension is needed to help insure that the severed ends of the tendon are kept apart and do not heal back to the same position. The heel extension is needed to keep the fetlock from dropping too much.
Dr. Redden gave a demonstration of opening sinkers at the sole wall junction at the toe, allowing serum to drain from the site rather than create increased pain and pressure. He also noted that while many foundered horses tend to grow over the shoe at the toe quarters, if you bevel the ground surface of the shoe for easy lateral breakover, this is less likely to happen. He then showed a video of several of his amputee cases with prostheses. These horses were amazing -- obviously healthy, happy and racing around the pasture without pain. The cost is too high to make this a routine treatment for horses, but it is certainly an option for some.
Tracy Turner, DVM, spoke about his research on the predictive value of diagnostic tests for navicular disease. He said that navicular needs to be differentiated from many other diseases with similar presentations: pedal osteitis; tendinitis; insertional tenopathy; bursitis; arthrosis; fracture of navicular bone; suspensory ligament desmopathy; impar ligament desmopathy; sole bruising; and P3 fractures. No doubt the variable results emanating from treatment of navicular disease is due largely to the fact that we are not always treating the same disease. Recent research has shown that the navicular bone is supplied with nerves that route through the impar ligament and collateral sesamoidian ligaments; therefore, nerve blocks to those areas -- palmar digital nerve, distal interphalangeal joint, and podotrochlear bursa -- should greatly reduce pain.
Dr. Turner studied 80 horses that were presented with heel pain and responded to posterior digital nerve blocks. Each horse was then tested with hoof testers; a frog pressure wedge; toe wedge; distal limb flexion; joint anesthesia; bursa anesthesia; blood flow test; various radiographs; scintigraphy; and contrast bursagraphy (which shows cartilage erosion and adhesions) in order to see what tests were most helpful in diagnosis.
The horses were defined as having navicular region pain if they responded individually to each of the following nerve blocks: coffin joint (DIP), posterior digital, and podotrochlear bursa. If they did not respond to each of the three nerve blocks they were categorized as palmar heel pain rather than navicular.
The single most diagnostic test for navicular disease was the coffin joint (DIP) block. The single most diagnostic test for palmar heel pain was the toe wedge. Surprisingly, hoof testers were of little help in differentiating navicular region pain from palmar heel.