Page 185 - Problem-Based Feline Medicine

11 – THE CAT STRAINING TO URINATE 177

output. Replacement therapy is not effective and not ● Urinalysis is more suggestive of a bleeding disorder
indicated. (hematuria; >5 RBC/hpf, <5 WBC/hpf) than an
inflammatory disease (pyuria > 5 WBC/hpf).
Cats with interstitial cystitis are more likely to have
– Erythrocytes in urine may be at various stages of
gastrointestinal signs and behavior abnormalities,
degeneration, suggesting chronic bleeding.
suggesting multiple organ abnormalities. Recent data
– Pyuria (>5 WBC/hpf) is not a feature of this
suggest interstitial cystitis represents a neuroendocrine
disease.
disorder rather than a primary bladder disorder.
● Urine is bacteriologically sterile.
● Crystalluria is usually absent, and when pres-
ent, the crystals (struvite) are of normal size and
Clinical signs
number.
More common in female cats in some countries, for
Radiography or ultrasonography.
example Australia, although equal sex distribution is
● Survey abdominal radiographs are usually
reported in other countries (USA).
normal.
Mainly occurs in cats 2–6 years of age. ● Contrast radiographs may reveal bladder wall
thickening and mucosal irregularities.
Typical history is of recurring bouts of hematuria
● Ultrasonographic finding may be normal or
lasting a few hours to several days associated with
reveal hyperechoic material presumed to be crys-
frequent urination and straining. The cat urinating in
talline in nature, blood clots and mural irregulari-
inappropriate places is also often reported.
ties or thickenings.
Abdominal palpation reveals a small contracted uri- ● Imaging can be used to exclude urolithiasis and
nary bladder, which is often painful on palpation. neoplasia.
The urine usually contains frank blood and the dura- Cystoscopic examination may show increased mucosal
tion of the hematuria may vary from a few hours to vascularity, superficial urothelial desquamation and
many days. Blood clots may be seen occasionally in the submucosal hemorrhage.
voided urine.
Bladder wall biopsy via cystoscopy is increasingly
being used in practice and may show epithelial hyper-
plasia, mucosal necrosis, muscular degeneration,
Diagnosis
edema, fibrosis, and perivascular accumulation of lym-
Diagnosis of non-obstructed idiopathic LUTD or idio- phocytes and hemorrhage.
pathic cystitis is one of exclusion. It is based on the
presence of signs of lower urinary tract disease, and
Differential diagnosis
exclusion of other causes of signs using urine culture,
and imaging techniques such as plain radiographs, con- Cystitis/urethritis typically occurs in middle-aged or
trast radiography and ultrasonography. older cats and is characterized by pyuria and bacteriuria.

History and physical examination can exclude urethral Urolithiasis occurs in middle-aged or older cats, and
obstruction. External abdominal palpation reveals a imaging reveals a urolith.
small, often firm, urinary bladder that may go into
Hypercontractile bladder is usually not associated
spasm on palpation. In contrast, with urethral obstruc-
with hematuria, despite signs of straining and pollak-
tion, the bladder is large on palpation.
iuria.
Urinalysis.
Neoplasia occurs in older cats and ultrasound or con-
● A voided sample is sufficient to confirm hematuria
trast radiography reveals a mass.
but a cystocentesis sample is required for urinalysis
and culture. If the bladder is empty at presentation, Behavioral causes of inappropriate urination are
the cat will need to be admitted and bladder fill mon- generally not associated with hematuria, dysuria
itored (see page 188, Infectious Cystitis). and stranguria.