It is often difficult to identify wooden foreign bodies by survey radiographs because they can be radiolucent. This article reports on 4 cases in which a wooden object perforated the bowel but diagnosis was delayed, even when the history included information on ingestion of wooden skews. This is a problem not only in veterinary medicine. A study of more than 200 human patients reported that foreign bodies were missed during the initial examination in 38% of cases. Ultrasonography is often used to detect and aid in removal of soft tissue foreign bodies. The acoustic properties of wooden objects vary depending on their physical density. They may be hyperechoic but over time they become progressively less echogenic and may become indistinguishable from the surrounding inflammation. It may be because they absorb fluid, altering their imaging characteristics. Failure to locate and remove wooden foreign bodies can lead to long-term inflammation or infection. When swelling along the body wall is found, a migrating foreign body should be considered. Ultrasonography can be a cost-effective method for detecting these objects; however, small splinters may be difficult to see and the longer the object is in place, the less echogenic it becomes.

COMMENTARY: Wooden foreign bodies, whether they are in the intestinal tract or soft tissues, are difficult to visualize using traditional radiographic techniques. Ultrasonography offers significant advantages for identifying these radiolucent materials. In addition to preoperative diagnosis, ultrasonography can be used intraoperatively to aid in localization, especially when the foreign body is in the soft tissues.

Ultrasonographic detection of ingested and perforating wooden foreign bodies in four dogs. Penninck D, Mitchell SL. JAVMA 223:206-209, 2003.