Page 206 - Problem-Based Feline Medicine

198 PART 4 CAT WITH URINARY TRACT SIGNS

orally every 12 hours) to minimize urethral resist- migration of the metanephric ducts (which become the
ance, if necessary. Parasympathomimetic drugs are ureters) was abnormal.
most likely to be effective when some neurologic
Ectopic ureters usually terminate in the urethra and
innervation is still present. Drug doses may be
less frequently in the vagina.
increased incrementally, if needed, every 4–5 days,
but patients should be carefully monitored for Approximately 50% are unilateral.
potential side effects (lacrimation, salivation,
Because of the close relationship of the mesonephros
abdominal cramps, vomiting, diarrhea).
and the metanephros and development of other urogen-
For increased urethral resistance or detrussor–ure- ital organs, other anomalies such as cystic (bladder)
thral dyssynergia. hypoplasia, renal hypoplasia, hydronephrosis and
● The direct-acting skeletal muscle relaxant, dantro- megaureter may also occur.
lene sodium (0.5–2 mg/kg orally 12 hourly or
Acquired ureteral ectopia may occur due to a vagino-
1 mg/kg IV) may be effective in reducing striated-
ureteral fistula developing as a sequel to cesarian and
muscle resistance.
ovario-hysterectomy.
● The alpha-adrenergic antagonist (phenoxybenza-
mine) may be effective in reducing smooth-muscle
resistance. Clinical signs
● Benzodiazepines such as diazepam (valium 2–5 mg
Congenital ureteral ectopia has been infrequently
PO tid) may reduce striated-muscle resistance.
reported in cats and there appears to be no breed or sex
Laboratory investigation, including plasma urea, creati- predisposition.
nine and electrolyte concentrations and urinalysis,
Usually reported in cats less than 18 months of age.
should be done to determine the degree of post-renal
azotemia and to identify if hematuria, pyuria and/or Signs depend on the site of termination of the ectopic
infection are present. ureter(s) and the presence of other congenital or
acquired abnormalities.
Prognosis Continuous or intermittent dribbling of urine is typ-
ical.
Prognosis in neurologic cases is guarded and generally
depends on the chronicity and severity of the neuro- Cats with bilateral ectopic ureters may or may not
logic lesion, response to medical therapy and the ease urinate normally, depending on how much urine
of manually maintaining an empty urinary bladder. refluxes back into the bladder.
Incontinent cats with unilateral ureteral ectopia urinate
ECTOPIC URETER(S)* normally.

Urine scalding may result in vaginal discharge, phi-
Classical signs
mosis (contraction of the prepucial orifice), and
● Young cat. perivulvar or periprepucial dermatitis.
● Continuous dribbling of urine.
Soiled hair may discolor.
● Wetness around the perineal area.
● Perineal dermatitis. The urinary bladder on abdominal palpation is not
distended (in contrast to urine retention with overflow).
Abdominal palpation may reveal an abnormal kidney(s).
Pathogenesis
Secondary bacterial urinary tract infections are
A congenital anomaly where one or both ureters fail common and may result in intermittent bouts of hema-
to terminate normally in the trigone of the urinary turia, cystitis and/or ascending pyelonephritis. With
bladder. Ectopic ureter occurs because the origin or bilateral ectopia, renal failure may occur.