Page 858 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Gastrointestinal system: 4.2 The lower gastrointestinal tr act 833

VetBooks.ir the condition, and characteristic haematological for retention of ingesta in the caecum, particularly at
the apex. The blind-ended nature of the caecum may
or abdominal fluid abnormalities have not been
reported. Haematological and abdominocentesis
results will vary with the degree of caecal compro- facilitate impaction formation.
mise. Definitive diagnosis is made during explor- Clinical presentation
atory laparotomy. Affected horses display signs of colic ranging from
mild and intermittent to severe and protracted.
Management Pain is usually mild and slowly progressive. Fever
Surgery is required. A typhlotomy and decom- should not be present. Heart rate is variably ele-
pression may be valuable for the immediate post- vated. GI sounds may be normal or decreased, but
operative period, particularly if caecal motility is there is typically a decrease in or absence of bor-
diminished. If the caecum is devitalised at the time borygmi over the right dorsal paralumbar fossa.
of surgery, a partial typhlectomy can be performed; Signs of cardiovascular compromise should not be
however, inability to remove the entire caecum, and evident.
the possibility of devitalised tissue at the anastomosis
site, may cause unacceptable morbidity and postop- Differential diagnoses
erative mortality in cases with significant ischaemic Colic due to a variety of other causes can present in
damage to the caecum. In these cases, intraoperative a similar manner.
euthanasia is often elected.
Diagnosis
Prognosis Physical examination and haematology are non-
The prognosis for caecal torsion is dependent on the specific. Palpation p/r is diagnostic. An impacted
viability of the tissues at the time of surgery. With caecum typically feels firm and doughy. Sometimes,
de-rotation early in the course of the disease, the the impaction is not palpable if it is present at the
prognosis can be good. Recurrence of caecal torsion caecal apex, but the medial caecal band is tight
is uncommon. If a congenital defect is detected at and difficult to move. Caecal impaction can occur
the time of surgery, recurrence of a similar problem concurrently with impaction of the large colon or
may be encountered. other abnormalities, so a thorough examination is
essential.
CAECAL IMPACTION
Management
Definition/overview Caecal impactions can be frustrating to treat because
Caecal impaction is relatively uncommon, but it is they tend to take longer to resolve than large-colon
the most common cause of caecal disease in horses. impactions. There are no clear guidelines for the
Arabian, Morgan and Appaloosa horses, and horses management of caecal impactions or when to inter-
>15 years of age may be at higher risk. vene surgically.
Medical treatment is usually attempted initially
Aetiology/pathophysiology and mainly involves feed restriction and fluid ther-
A variety of risk factors have been identified or sug- apy. Intravenous fluid therapy is useful and may
gested. These include general anaesthesia, pain, hos- speed resolution if an adequate volume is used.
pitalisation, poor dentition, poor-quality feed and Enteral fluid therapy may also be used but should
parasitic infestation. The role of tapeworms in caecal be used less aggressively than in the management of
impaction is controversial. Hypertrophy of the cae- large-colon impaction. Mineral oil, DSS or osmotic
cal base may also be a cause of chronic or recurrent cathartics (e.g. sodium sulphate) are often used,
caecal impaction. but their efficacy is unclear. Analgesics should be
The pathophysiology is unclear, but likely involves administered as required. The potential usefulness
decreased or abnormal caecal motility. This allows of prokinetics is currently unclear.