Pets have the unfortunate tendency to eat things they should not, and we are not talking about food. Toys, socks, rocks and other materials find their way into pets' stomachs. But when the foreign body is a string, the consequences are especially dire. Animals like to play with things, and play often involves chewing. Chewing leads to accidental swallowing, and from that, disaster can ensue. Pets of any age will play with toys, but it is generally the youngsters who get into trouble with foreign bodies. Common objects that are swallowed include corn cobs, balls, socks and underwear, rocks, jewelry, toys, leashes and collars, plastic bags, pieces of shoes, coins, sewing needles and fishhooks. Often these objects will pass out the other end in a day or two, though it is possible for a small object to rattle around the stomach without passing for weeks. If the object does not pass and causes obstruction or partial obstruction, surgery will be needed to remove it. Prompt diagnosis allows for prompt removal of the foreign body before the bowel is badly damaged. In more advanced situations, sections of damaged bowel must be removed and in the worst possible scenario, the intestines break open and spill bacteria and digested food throughout the abdomen. This latter possibility is associated with a very high mortality rate and is to be avoided at all costs. As if this were not bad enough, there is an especially bad foreign body situation when the object is a string or similar linear structure. Common linear foreign bodies might include string or yarn or tinsel during this Christmas season.
Imagine a drawstring bag. Tie a knot in one end of the drawstring so that it cannot move and pull on the other end. The fabric wads up along the string channel. If the string was pulled hard enough and the knot still will not budge, the string will actually rip right through the string channel. This is what happens in the linear foreign body scenario. The foreign body lodges somewhere in the GI tract and will not move. The string, however, dangles forward in the GI tract like a drawstring. The intestine attempts to move it forward but because the foreign body is lodged, the bowel ends up inching up the string similar to the drawstring channel on the pants or like an accordion. This type of folding upon itself is called plication and is the hallmark of the linear foreign body. If the linear foreign body is not removed, this can lead to life-threatening peritonitis.
The linear foreign body is particularly difficult to diagnose. Strings are too small to see on radiographs. Frequently the only hint is evidence of plication on the radiograph or by ultrasound, and even then the pattern is likely not going to be definitive. The decision to go to surgery is likely going to have to be made based on how sick the patient looks and information from the imaging.
The linear foreign body surgery is generally considered a higher mortality situation than those of more simple foreign bodies. The major concern for all veterinarians is that the linear foreign body has not damaged the intestines or cut through them to allow a secondary peritonitis. Do not let your dogs and cats play with yarn, strings, ribbons or tinsel this Christmas season.
Dr. Karsten Fostvedt is a veterinarian at St. Francis Pet Clinic in Ketchum.