Thank you for the additional information.
I'm curious if the swelling you are noting is more associated with how she is loading the limb and the bodies response to the change in weight
bearing on different parts of the foot.
I would be concerned with a developmental change associated with the bone leading to abnormal growth and conformation. We can see things like Juvenile arthritis, contraction of the flexor tendons, trauma to the second or third pastern bones all leading to the clinical signs that you are describing.
I would highly recommend examination by your horses veterinarian with radiographs (X-rays) to determine the conformation of the bony column of the lower limb and rule out some of the more serious causes like fracture of the coffin bone, fracture of the navicular bone, juvenile arthritis, ect.
Depending on what the radiographs show, corrective trimming or shoeing may be required to aid in conformation and load bearing on the limb. Also, depending on what shows on the radiographs, a more specific treatment can be instituted. Some times treatment of specific joints are required, or in the case of flexor tendon contraction surgery to reduce the tension/pull on the coffin bone may be required. It really depends on the cause to why she is not loading the limb appropriately (starting to push over the hoof making her walk on the front). There may even be heel pain leading to increased weight bearing on the toe.
As she is a young growing horse, getting this properly diagnosed sooner rather than later allows for corrective trimming/shoeing measures to be more effective. As she continues to mature, it becomes more and more difficult to address the issues.
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