Page 799 - Problem-Based Feline Medicine

35 – THE CONSTIPATED OR STRAINING CAT 791

● Modify the diet to minimize urine concentration by Abdominal radiographs may also be useful in visual-
using canned food or add water to dry food. If urine izing the mass. The obstruction may be caused by
pH is > 6.5 and there is struvite crystalluria, maxi- intraluminal or extraluminal masses.
mize urine acidity, and minimize magnesium intake
using a diet designed to reduce struvite formation.
Differential diagnosis
● Amitriptyline (2.5–12.5 mg/cat PO q 24 h) may be
effective in reducing clinical signs in cats with idio- Abdominal neoplasia must be differentiated from other
pathic cystitis. causes of abdominal masses such as an obstructed
● Empirical use of antibiotics, anti-inflammatory bladder or trichobezoars (hairballs). This can be done
agents and antispasmodics is controversial. by abdominal ultrasonography or radiographs, and
clinical signs.
Obstructive LUTD is a medical emergency.
● Therapeutic strategies are directed at relief of the
obstruction and supportive therapy as needed. Treatment
For prevention, use specific diets for struvite and
Treatment of abdominal neoplasia depends on the
calcium oxalate uroliths, and maximize dietary
type of tumor identified on histopathology. Surgical
water intake.
excision should be performed, sometimes followed by
See a detailed discussion on obstructive LUTD see a chemotherapeutic protocol, depending on the
page 179 (The Cat Straining to Urinate). histopathological diagnosis.

DRUGS
NEOPLASIA
Classical signs
Classical signs
● History of drug use, such as opiates or
● ± Palpable abdominal mass. kaolin/pectin.
● Straining, hard, dry feces. ● Signs of constipation.

Clinical signs Clinical signs
Abdominal neoplasms may obstruct the passage of There are signs of constipation, such as reduced fre-
feces along the large intestine. quency of defecation, and straining, with an appro-
priate drug history, such as the administration of
Signs of neoplasia, such as weight loss and a palpable
opiates or kaolin/pectin.
abdominal mass, may accompany the clinical signs of
constipation and straining. Overzealous use of furosemide promotes dehydra-
tion which predisposes to constipation.
An abdominal mass may be palpable.
The abdominal neoplasms that have the potential to
Diagnosis
cause constipation because of their anatomical position
and prevalence in cats are lymphosarcoma of the intes- The diagnosis is made by a thorough drug history and
tine or abdominal lymph nodes, intestinal adenosar- evidence of constipation on abdominal palpation or
coma and intestinal mast cell tumor. radiographs.

Diagnosis
Differential diagnosis
Abdominal neoplasms are most readily diagnosed by
abdominal ultrasound followed by fine-needle aspi- Drug-related causes of constipation should be differ-
rate biopsy or surgical biopsy and histopathology. entiated from other causes of constipation that do