Page 696 - Problem-Based Feline Medicine

688 PART 9 CAT WITH SIGNS OF GASTROINTESTINAL TRACT DISEASE

ultrasound guidance may be useful, but because of the Despite surgical removal, cats with intestinal mast
poorly differentiated nature of the tumor they may also cell tumors rarely live longer than 4 months.
be non-diagnostic.
Analysis of peritoneal effusion fluid may be helpful if FOREIGN BODIES*
mast cells are present, but as with fine-needle aspirates,
the effusion may be suggestive of neoplasia, but not Classical signs
necessarily give a definitive diagnosis.
● The classical sign is an acute onset of
Definitive diagnosis requires histopathologic exami- frequent vomiting.
nation of the tissue, which is usually best achieved by ● Intermittent vomiting will occur in some
wide surgical resection and anastomosis. cats with foreign bodies that are causing
an intermittent or incomplete obstruction
Staging of the tumor is achieved by biopsy of mesen- (e.g. string).
teric lymph nodes, spleen, liver and bone marrow aspi-
ration (if indicated). The tumor rarely metastasizes
See main reference on page 636 for details.
out of the abdomen.

Clinical signs
Differential diagnosis
The classical sign is an acute onset of frequent vom-
Other intestinal neoplasia, foreign body, fungal or algal
iting, but intermittent vomiting will occur in some cats
disease, inflammatory bowel disease, and extra-
with foreign bodies that are causing an intermittent or
intestinal causes of anorexia, weight loss and vomiting
incomplete obstruction (e.g. string).
(chronic renal failure, hyperthyroidism, etc.) are all dif-
ferentials that should be considered. There may or may not be palpable abnormalities in the
intestinal tract, and most cats will be clinically normal
otherwise.
Treatment
Surgical resection is the only known treatment.
Surgical margins must be > 5 cm beyond the visible Diagnosis
edge of the lesion because of the cellular invasion that The definitive diagnosis is usually made by contrast
occurs along the tumor mass. radiography, however, survey radiographs or ultra-

Metastasis occurs early in the course of the disease sound examination may also reveal abnormalities that
to the spleen, liver and regional lymph nodes. are consistent with a GI foreign body.
Other forms of therapy (chemotherapy, radiation, etc.) String foreign bodies often are found attached to the
have either been ineffective or not evaluated. base of the tongue, thus a thorough oral exam is
Adjunct therapy with cimetidine, anti-histamines always essential in cats with a suspected GI foreign
and prednisone may be tried to control signs associated body.
with mast cell degranulation, but are often not helpful Some foreign bodies can be found and retrieved by gas-
because these tumors are typically poorly differentiated trointestinal or colonic endoscopy. In many cases,
and do not produce granules or GI ulcer disease. these foreign objects are metallic and will be visible on

Nutritional support (enteral or parenteral nutrition) survey radiographs.
may be required for cats that do not want to eat or are
vomiting.
Differential diagnosis
Gastric parasites, heartworm disease, Helicobacter spp.
Prognosis
gastritis, food intolerance, food allergy, and antral
The prognosis is poor for cats with this disease. pyloric hypertrophy or stenosis are primary differentials