Navicular bone cyst in sound horse!

 The following radiographs are of a horse's front feet. Specifically, the views are isolating the navicular bone. This horse was being evaluated as a prospect dressage horse and was completely sound during the prepurchase exam. The gelding was approximately 7 years old and there was no history of lameness.
As recommended by the examining veterinarian (me), the front feet were radiographed with plans to radiograph the hocks as well. However, a large cyst was identified in the left navicular bone.

Compared to the right navicular bone (image below), an irregularly shaped lucency (dark circle) is present in the center of the navicular bone (image above).  Although the gelding was not lame, the exam was stopped and the horse was FAILED for sale and intended use.  Everyone involved (including myself) were very surprised with the radiographic findings. However, navicular bone cysts are significant findings and will likely result in poor performance and lameness at some point in the future. As I tell my clients, my crystal ball is "cloudy" at best; however these findings are considered a deal breaker. 

This case represents another example of the importance of a thorough prepurchase exam when acquiring a horse of any price (especially a free horse). In addition, I feel strongly that foot radiographs should be a part of all prepurchase exams due to the essential role the fore feet play in equine soundness.