Ingested, nondigestible objects that result in partial or complete obstruction of the intestinal lumen.
Gastrointestinal system primarily affected. Cardiovascular compromise may be seen with peritonitis/sepsis.
Although considered common, the true incidence has not been reported.
Species. Domestic cats.
Breed predilection. None.
Age and range. More common in young cats, mean age 2.7 years; range 6 months to 10 years.
Gender. No sex predilection.
Ingestion of nondigestible objects. Approximately 50% of foreign bodies in cats that require surgical intervention are linear foreign bodies. Leaving such materials as thread, yarn, string, and tinsel in accessible areas. Toys with attached strings.
Pathophysiologic alterations with nonlinear foreign bodies primarily relate to gastrointestinal tract obstruction. Severity of alterations are determined by location of foreign body, whether it is moving through the intestinal tract, degree of obstruction, and occurrence of devitalization or perforation of the intestinal wall. Intestinal distention due to gas and fluid proximal to the foreign body increases intraluminal pressure, causing changes in intestinal hemodynamics and subsequent fluid sequestration in the intestinal lumen. Dehydration and electrolyte imbalances are common, secondary to fluid sequestration and vomiting. Circulatory compromise can interfere with the intestinal mucosal barrier, allowing absorption of bacterial toxins and potential bacterial translocation.
Linear foreign bodies typically cause only partial obstruction, so distention with fluid and gas is less severe. Peristaltic contractions attempt to push the foreign body aborally but since it is "fixed," it becomes stretched taut. Further peristaltic contractions cause the intestine to gradually gather along the foreign body in an oral direction, producing the classic plicated or pleated appearance. The foreign body can become embedded in the intestinal wall at the mesenteric border or erode through the intestinal wall, resulting in marked inflammation and peritonitis. Chronic inflammation can interfere with intestinal motility and function even if the foreign body is successfully removed.
In some instances, the owner witnesses ingestion or the foreign body is seen in the mouth. Other common presenting signs are lethargy, listlessness, partial to complete anorexia, and intermittent or persistent vomiting.
The physical examination may be unremarkable. Dehydration is common. Careful evaluation of the oral cavity, particularly under the tongue, is important-in approximately half the cases of linear foreign bodies, the item becomes fixed under the tongue. It may become fixed anywhere along the gastrointestinal tract, with the stomach as the next most common site. Abdominal pain/tenderness, a palpable object, intestinal distention, or "bunching" of the intestine may be appreciated during abdominal palpation.
Generally mild to moderate. Influenced by degree of obstruction and presence or absence of peritonitis.
Radiodense foreign bodies are apparent on survey abdominal radiographs. Intestinal obstruction is characterized by presence of several gas-filled intestinal loops of varying diameters. Radiographic signs of linear foreign bodies include accordion-like pleating, shortening, or gathering of the intestine in the cranial to midventral abdomen. Eccentrically located luminal gas bubbles that are tapered at one or both ends is a characteristic find-
ing. One study showed that the presence of three or more tapered (comma-shaped) gas bubbles was always associated with a linear foreign body. Contrast radiographic studies can be performed in questionable cases but generally are unnecessary.
Radiolucent nonlinear foreign bodies may be identified using ultrasonography in the absence of extensive gas accumulation. Ultrasonography may also show the plication or pleating caused by a linear foreign body. In some instances, the item can be identified as a hyperechoic structure within the lumen.
The CBC may be normal, but common hematologic abnormalities range from leukocytosis with or without left shift to a degenerative left shift in cases involving intestinal perforation and peritonitis. Dehydration can cause increases in hematocrit and total protein as well as prerenal azotemia. Hypokalemia, hyponatremia, and hypochloremia are common in vomiting cats.
Some foreign bodies are evident on abdominal palpation. Radiographic or ultrasonographic evaluation of the abdomen may identify the foreign body or suggest bowel obstruction. In some cases, definitive diagnosis is made during exploratory celiotomy.
Enteritis, intussusception, neoplasia, dysautonomia.
Early surgical intervention is recommended after the patient has been stabilized through correction of fluid and electrolyte derangements. Always examine the oral cavity thoroughly, especially under the tongue, for a linear foreign body. Approximately 50% of linear foreign bodies are fixed under the base of the tongue.