It’s one thing to say “soundness” exam in writing but it’s much easier if you can see the horses movement before treatment. Here is a video of pre treatment Cassandra.
Video of Cassandra pre treatment
the stride. So when Cassandra was reaching forward with her leg she was throwing her foot forward using her shoulder muscles, thus the irregular stride. It’s also a very unique “broken leg” for a horse because the hoof acts as a cast to hold the bone in place so they can continue to “walk” on the leg. That also comes with it’s own faults in that any swelling is incased in the hoof and can cause more pain. Photo taken June of 2010 showing the broken extensor process (left photo indicating 15.68mm chunk) the 6 is right over the chunk of bone.
One other treatment that we did not do at the time but would do if this occurs in any of our horses going forward is Magnets. You have to make sure that you have a deep penetrating magnet to get through the hoof wall and you have to make sure that you apply the north polarity side to the horse's hoof to get the desired healing affect. But it works like the ultrasound to stimulate self healing in the body. Magnets like the ultrasound have been successfully used for tendons, bone and skin therapy. I personally like to use the Neodymium magnets because they are stronger/deeper penetrating per size of the magnet. Be careful with how long you use magnets because they are heat producers. You can alternate with cold therapy and magnets but don't alternate with heat and magnets. With or without surgery you can try using Magnet therapy to help ease arthritis and inflammation. Also check with your vet to see if any injections or medications you are using are not suitable to be used with Magnets.
Here are some photos of the other horse that had something similar.