Page 784 - Problem-Based Feline Medicine

776 PART 9 CAT WITH SIGNS OF GASTROINTESTINAL TRACT DISEASE

Isospora: Sulfadimethoxine (25 mg/kg PO q 24 h for Ultrasonographic examination of the pancreas is
10–14 days) a good method of detecting pancreatic abnormali-
ties. However, this is still not a specific or sensitive
Cryptosporidia: Azithromycin (5 mg/kg q 24 h PO for
test for pancreatitis.
5 days then q 48 h)
Elevations in serum trypsin-like immunoreactivity
Toxoplasmosis: Clindamycin (10–25 mg/kg PO q 12 h)
(TLI) have been used as a screening test, but caution is
(high dose recommended but often causes GI side
advised because the assay often has false-negative and
effects), or azithromycin 5 mg/kg q 24 h for 5 days
-positive results.
then q 48 h.
Feline pancreatic lipase immunoreactivity (fPLI) is
the most specific and sensitive serum test for pan-
CHRONIC PANCREATITIS
creatitis currently available. fPLI is 100% specific for
pancreatitis.
Classical signs
fPLI and ultrasound examination, when used together,
● Clinical signs are vague and non-localizing
have a sensitivity of >90%.
in cats (e.g. lethargy, anorexia).
● Vomiting or diarrhea are less common.
● Hematochezia or large bowel diarrhea
occur more often with chronic pancreatitis. PERINEAL HERNIA

See main reference on page 318 for details. Classical signs
● Straining to defecate.
Clinical signs ● Large bowel diarrhea.
● Irritation or perineal swelling.
Anorexia and lethargy are the most common signs
associated with feline pancreatitis.
Vomiting is less common (< 50% of cats vomit) and Pathogenesis
thus, dehydration is less common.
Perineal hernia occurs when there is failure of the
Chronic pancreatitis is also associated with vague clin- pelvic diaphragm musculature to support the rectal
ical signs, but hematochezia or large bowel diarrhea wall. A peritoneum-lined sac protrudes through the
may be observed. defect and may contain pelvic and abdominal contents.
The rectal wall stretches and deviates into the sac.
Diagnosis
Feces are retained in the divided section of the rectal
There is no single, definitive test for pancreatitis in wall resulting in straining and difficulty defecating.
cats.
Weakness of the pelvic diaphragm musculature and
Non-specific abnormalities on the hemogram may herniation is often idiopathic but may be associated
include neutrophilia or mild, non-regenerative anemia. with previous perineal urethrostomy, megacolon, per-
ineal mass or chronic colitis.
Serum chemistry abnormalities may include elevated
liver enzyme activities and/or hyperbilirubinemia.
Serum amylase and lipase are of no use in the cat
Clinical signs
for diagnosis of pancreatitis due to false-negative and
-positive results. Straining to defecate, constipation or less com-
monly, large bowel diarrhea, irritation or perineal
Loss of visceral detail or increased duodenal gas are
swelling are all typical signs of perineal hernia.
sometimes observed on survey radiographs, but this is
not consistent. Usually older cats are affected.