It has been reported that 60% of the lameness in horses is due to arthritis. Dr. Wayne McIlwraith from Colorado State presented an update on medical options for treatment of arthritis at the 2006 AAEP convention.  One of the newest treatments in horses is the availability of underwater treadmills.  Although no controlled studies have been performed, many believe these treadmills allow horses to use the joints sooner after surgery or injury and potentially prevent stiffness of the joint.  Extracorporeal shock wave therapy also was proven to be beneficial in treatment of horses with joint disease in a small study. 

The most common class of drugs used in treatment of arthritis is the non-steroidal antiinflammatory drugs like phenylbutazone (called bute).  Although some laboratory research has indicated that bute could have a damaging effect on joint cartilage, Dr McIlwraith feels that until actual studies in live horses prove that it is damaging, the use of bute is still justified.  The most common treatment of arthritis in the horse is injecting cortisone in the affected joint.  Of the two most commonly used types of cortisone, Vetalog has been shown to cause less damage in high motion joints such as the coffin joint and fetlock.  The use of Depo-Medrol in joints has been shown to cause some cartilage damage so it is only recommended to use Depo-Medrol in low motion joints such as the lower hock joints.  Many veterinarians will also inject hyaluronic acid in the arthritic joints along with cortisone because hyaluronic acid may protect the joint from damage by the cortisone as well as increase the effect of the treatment.  Join us next time for more on treatment of arthritis.