Page 819 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

794 CHAPTER 4

VetBooks.ir Prognosis Clinical presentation
Ingestion of foreign bodies may occur in horses of
The prognosis for reducible intussusceptions is
fair and is a reflection of the portion of intestine
involved, the chronicity, the amount of damaged any age, but younger horses may be more commonly
affected due to their adventurous nature. The clini-
tissue and the surgical procedure required to cor- cal signs are usually non-specific and may manifest
rect the lesion. For irreducible intussusceptions the over several weeks. The clinical signs may vary
prognosis is poorer, the surgical techniques for cor- according to the location of the foreign body as well
rection are more technically demanding and postop- as the severity of intestinal obstruction. The most
erative complications are common. common clinical signs are colic of variable frequency
and severity, anorexia, lethargy, weight loss and
FOREIGN BODIES abdominal distension. Horses may continue to pass
faeces depending on the location and completeness
Definition/overview of the obstruction. In some cases, acute peritonitis
Ingestion of items that are not normal components without any preceding signs may occur secondary to
of the diet may result in obstruction of and/or dam- intestinal perforation.
age to the intestinal tract.
Differential diagnosis
Aetiology/pathophysiology Other causes of non-strangulating obstruction (e.g.
Foreign body ingestion may occur as a result of phytobezoars, food impaction) are the major differ-
accidental ingestion of foreign material contained ential diagnoses for foreign body impactions.
in feed or intentional ingestion of abnormal items
(pica). The irregular shape and indigestibility of Diagnosis
foreign bodies may cause them to lodge along the Palpation per rectum may be useful for identifying
GI tract. Consequent to slow intestinal transit, for- distended bowel, but in most cases it is not possible
eign bodies accumulate ingesta within and around to palpate the foreign body. Gastroscopy is effec-
themselves. The adherent ingesta begin to solidify, tive at diagnosing gastric foreign bodies. NG reflux
increasing the size of the mass (enterolith) and pre- is characteristic of more proximal obstructions but
cluding breakdown, which contributes to lodging of is not specific to foreign bodies. Ultrasonographic
the mass in the intestine. examination may show distension of the bowel, but
As with other causes of bowel obstruction, GI for- it is unusual to be able to visualise the obstruction.
eign bodies result in gas/fluid distension of the bowel Radiography is useful for the diagnosis of entero-
proximal to the obstruction. In proximal obstruc- liths provided that suitable equipment is available.
tions this may lead to gastric distension and reflux; A definitive diagnosis is usually made during an
however, gastric reflux may also develop in cases of exploratory laparotomy.
large-bowel obstruction. Lodging of a foreign body
within a section of bowel may lead to ischaemia Management
and pressure necrosis, increasing the likelihood of Some cases may be managed medically by hydrat-
intestinal rupture at the site of the obstruction. Less ing the bowel using frequent, large volume enteral
commonly, rupture may occur more proximal to the fluids. If unresponsive to medical therapy, an explor-
obstruction due to marked distension of the bowel. atory laparotomy and enterotomy are indicated to
Penetrating foreign bodies may lead to abscess or identify and remove the foreign body and any asso-
sinus formation. This may also result in adhesion ciated damaged bowel (Figs. 4.121, 4.122). In some
formation between abdominal organs. Leakage cases, the foreign body may need to be massaged
from an abscess or sinus tract caused by a penetrat- aborally to a location more suitable for enterotomy.
ing foreign body has the potential to cause severe Behavioural reasons for foreign body ingestion
peritonitis. should be addressed to minimise the likelihood of
recurrence.