Page 208 - Problem-Based Feline Medicine

200 PART 4 CAT WITH URINARY TRACT SIGNS

Diagnosis Clinical signs

Diagnosis is via radiography using retrograde ure- Normal or small urinary bladder.
thrography.
Intermittent leakage of small volumes of urine, often
Following catheterization of the urethera using an while the cat is sleeping or relaxed.
open-ended cat catheter, contrast is injected (1–2 ml)
If congenital in origin, other anomalies, such as vaginal
while the radiographs are taken. Avoid over-distending
aplasia and cystic hypoplasia are commonly present.
the urinary bladder.
Many FeLV-positive cats with urinary incontinence
Urodynamic procedures such as urethral pressure
may also have anisocoria, reproductive disorders,
profilometry may be used to identify focal urethral
weight loss, vomiting and ptyalism suggesting a multi-
obstructions.
focal autonomic dysfunction. In cats with FeLV-asso-
ciated incontinence, digital palpation of the urinary
Treatment bladder often elicits a urine flow.
Treatment depends on location and size of the stricture. In cats with urethral incompetence due to neoplasia,
abdominal palpation may reveal a mass at the bladder
Extrapelvic strictures may be managed by urethros-
neck. Others signs, such as dysuria and hematuria are
tomy, whereas, intrapelvic strictures may require ure-
often present.
thral resection and anastomosis.
Secondary urinary tract infections are common.
URETHRAL INCOMPETENCE*
Diagnosis
Classical signs
Diagnosis is based on history and clinical signs of leak-
● Small urinary bladder.
age of small amounts of urine, often when sleeping, and
● Intermittent dribbling of urine.
a normal or small bladder.
Ophthalmological signs (anisocoria) may suggest the
Pathogenesis incontinence is associated with FeLV infection.
Incontinence occurs because of reduced urethral outflow A positive FeLV test.
resistance during urine storage. This results from lost or
Retrograde contrast vaginourethrography in female cats
reduced urethral smooth or striated muscle tone.
with urethral hypoplasia shows marked urethral short-
Reported causes of urethral incompetence include: ening and other anomalies, such as vaginal aplasia and
● Pelvic and pudendal nerve damage following cystic hypoplasia.
trauma (cystotomy, perineal urethrostomy) and
Cystography or retrograde urethrography may reveal a
rarely neoplasia (acquired urethral incompe-
mass at the bladder neck. Biopsy is necessary for a
tence).
definitive diagnosis.
● Dysraphism in Manx cats.
● Urethral hypoplasia has been reported in young Urodynamic procedures, including urethral pressure pro-
female cats (congenital urethral incompetence). filometry can be used to identify urethral incompetence.
● A relationship between incontinence and feline
leukemia virus (FeLV) infection is suspected.
● Reproductive hormone-responsive incontinence Differential diagnosis
has been reported in two female cats following Hypercontractile bladder (urge incontinence) is charac-
ovariectomy and suspected in three neutered terized by frequent conscious urination and a small
males. bladder.