CPD ACCREDITED ARTICLE
Caution should be used when interpreting the signifi-
cance of bacterial cystitis in horses with incontinence. In
rare cases primary cystitis may be a direct cause of urinary
incontinence 7 . Inflammation of the bladder wall in such
cases leads to detrusor over activity and increased intra-
vesicular pressure, which causes incontinence. A much
more common scenario however, is the development of
secondary cystitis, usually due to urinary retention and of-
ten accompanied by deposits of sabulous sediment in the
bladder. Cystitis in these causes is thought to be caused
by the constant irritation of the mucosa by the crystalloid
material and/or ammoniagenesis by bacterial within the
sediment 18 . Over time, chronic inflammation of the blad-
der wall leads to cicatrical pillars within the lumen of the
bladder that permanently alters bladder distensibility and
impairs normal detrusor function.
Endoscopy
Endoscopy is a useful diagnostic modality for horses with
urinary incontinence and should be performed in all cases
where a clear etiology has not been identified. Non-spe-
cific findings that are associated with most cases of chron-
ic urinary incontinence include mucosal hyperaemia,
haemorrhage and fibrin accumulation (Figure 6); often in
combination with deposits of sabulous sediment. Dilated
ureteral openings caused by chronic bladder distension
cases of post parturient bladder trauma. A thickened irreg-
ular bladder wall and the presence of soft tissue masses
may be seen in cases of bladder neoplasia. Ectopic ureter-
al orifices can be visualised in the vestibule and vagina of
females and pelvic urethra of males.
Ultrasonography
Transrectal ultrasonography may be useful to rule confirm
the presence of sabulous cystitis and to rule out uroliths,
neoplasia or congenital anomalies, particularly if the veter-
inarian does not have access to an endoscope.
Urethral and bladder pressure profiles
Horses that are able to generate some degree of intravesic-
ular pressure are more likely to respond to treatment and
therefore measurement of bladder and urethral pressures
to assess urinary sphincter and detrusor muscle function
may have some prognostic value. Normal values for mares
and geldings have been reported 21, 22 ; however the equip-
ment is usually only available in specialised centers and is
therefore usually the remit of veterinarians based at referral
centers or academic institutions.
V. Treatment of urinary incontinence
Treatment for urinary incontinence varies depending
upon the underlying cause, but in general, the therapeu-
tic aims are to resolve any underlying primary problems;
encourage bladder emptying and to treat and prevent any
secondary complications.
Once bladder paralysis occurs, sabulous sediment should
Figure 6: Endoscopic view of the bladder of a horse with chronic uri-
nary incontinence. Notice the mucosal hyperaemia, hemorrhage and
fibrin accumulation. Photo courtesy of Derek Knottenbelt.
and detrusor dysfunction may also be seen in cases with
long-standing incontinence. These horses develop vesic-
ulouretral reflux and are at risk of ascending bacterial in-
fections.
In some cases, a specific finding on endoscopy may en-
able to veterinarian to make a definitive diagnosis. Cystic
calculi, mucosal hyperaemia and thickening of the blad-
der wall will be seen in cases of urolithiasis. Transmural
bruising, mucosal hyperaemia and necrosis will be seen in
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Issue 02 | APRIL 2017 | 18
Figure 7: Removal of sabulous sediment form the bladder via catheter
lavage. A temporary urethrostomy was used to facilitate the proce-
dure in this gelding