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Flashcards in Incontinence in small animals Deck (38):

Categories - urinary incontinence

- neurogenic/ non-neurogenic
- by presenting sign: congenital, overflow, stress, urge, paradoxical, by response to tx, hormonal
-useful aid to problem solving but not dx


Causes of juvenile canine incontinence

- ureteral ectopia
- congenital USMI
- genitourinary dysplasia
- bladder hypoplasia
- intersexuality
- pervious urachus
- neurological dz
- combinations of above.


Causes of adult canine incontinence

- prostatic dz
- neurological dz
- urogenital neoplasia
- fistulae
- bladder atony
- cystitis
- detrusor instability
- pelvic masses
- combinations/ others


Define and decribe USMI

= Urethral sphincter mechanism incompetence
- common cause of incontinence in dogs, esp neutered bitches, although castated male dogs and entire bitches can bee affected
- usually acquired but may be congenital and may occur with anatomical defects (ureteral ectopia, intersexuality)
- usual sign is urine leakage during recumbency
- severity of leakage variable
- often follows neutering


Pathophysiology - USMI

- mutlfactorial aetiology
- medium-large breeds most commonly
- factors: anatomical, hormonal, environmental, unknown


USMI - risk factors

- prevalence 3-12% post-neutering
- 75% cases develop within 3 years of neutering
- certain breeds (irish setter, rottweiler, OESD, doberman)
- docked dogs and dogs >20kg significantly more at risk
- effect of prepubertal neutering unclear
- causal effect on neutering unclear (not d/t adhesions, possibly oestrogen and protegesterone levels and gonadotrophin effects)



- PE unremarkable
- Dx based on hx, CS, investigation, response to trial tx, r/o other causes
- caudally positioned bladder neck is supportive but not diagnostic


USMI in mae dogs

- uncommon
- congenital/acquired
- acquire more likely in castrated larger breeds
- leak predominantly when recumbent (suggests similar mechanism of inreased abdominal pressure --> resting urethral resistane)
- intrapelvic bladder neck adn castrration statistically signficant factors
- responds to medical tx less well than bithc
- sx described


What is ureteral ectopia?

= ureters pass bladder and open into urethra or occasionally into vagina
- congenital > acquired
- inherited/ familial in some breeds (golden retriever)
- females> males
- dogs > cats
- bilateral/unilateral
- openings may be single/ double/ elongated (troughs)


Describe differences between dog/cat ureteral ectopia

- dogs most likely to have an intramural ectopic ureter
- cats usually have extramural ectopic ureter


CS - ureteral ectopia

- continued dribbling urinary incontinence
- may have severe scalding
- frequently associated with UTIs
- may have concomitant SMI
- may have other abnormalities (hydronephrosis, hydroureter, rarely ureterocoeles)


Describe genitourinarydysplasia

- rare cause of urinary incontinence in cats and v occasionally dogs
- more common than ectopic ureters in cats
= congenital developmental abnormality affecting vagina and urethra


Other causes - urinary incontinence - 4

- INTERSEXUALITY: rare cause of juvenile incontinence, incontinence most frequently d/t urine refluxing into another structure, may also get concomitant SMI. Tx depends on underlying defect, frequently sx.
- BLADDER HYPERPLASIA: rare, usually associated with other congenital defects e.g. bilateral ectopic ureters, diagnosed radiographically, signs d/t low volume, poorly compliant bladder --> overflow, guarded px
- BLADDER ATONY: usually secondary to bladder distension, tight junctions in bladder wall disrupted --> atonic bladder and urinary retention with overflow, px guarded, tx requires indwelling catheter.
- PERVIOUS URACHUS: v rare in cats/dogs, more likely in farm spp.


Approach - urinary incontinence

Hx --> PE --> clincail pathology (urine, investigate PUPD if present) -->trial tx if suspect USMI --> diagnostic imaging/ endoscopy


Role of diagnostic imaging in urinary incontinence

- cause urinary incontinence
- result from incontinence


What diagnostic imaging should be used?

- Plain films (RLR, VD)
- IVU (IV urography)
- Retrograde study: most useful as provides most information on intra-pelvic anatomy
- ultrasound: confirm normal ureteral emptying into bladder, additional info on kidneys, bladder, prostate
- others


Outline endoscopy in urinary incontinence diagnosis

- excellent visualisation: ectopic ureters, other lesions of urethra --> bladder neck which may --> incontience. Subjective indication of urethral tone
- can facilitate biopsy
- recently used to tx intramural ectopic ureters using a laser
- no information of urethro-pelvic relationships
- not widely available in UK


Tx - urinary incontinence

- ideally based on definitive diagnosis
- without this tx is TRIAL and SYMPTOMATIC
- not necessarily undesirable provided owners understand this is the case


Medical tx - urinary incontinence

- Tx UTI (base on C+S, confirm eradication)
- Tx underlying systemic dz (PUPD may exacerbate or precipitate condition)
- Diet if obese
- specific medication depends on dx


Medical tx - SMI in dogs

* Phenlypropanolamine = PPA (most effective)
- Ephedrine hydrochloride (cheaper)
>>> both of above are alpha-adrenergic agonists


Which disorders have sx options?

- only with definitive diagnosis
- ureteral ectopia
- USMI in dogs (female and male)
- genuto-urinary dysplasia
- congenital genito-urinary malformations
- bladder, urethral or vaginal masses
- prostatic dz


Management pre-sx

- UTI and obesity to be managed 1st
- owners should be given realistic expectations as success not guaranteed


Sx tx options for SMI

- MOST SUPPORT: colposuspension, urethropexy, prosthetic sphincter, endoscopic injection of collagen
- OCCASIONAL REPORTS: vas deferens pexy, urethrocystoplasty (cats), sling urethroplasty, cysto-urethropexy, other transpelvic slings, other variations/ combinations


Principles - sx for USMI

- improve pressure transmission to bladder neck
- increase urethral resistance
- or both


What is colposuspension?

- oldest described method
- aims to move and retian bladder neck into intra-abdominal position to allow equal pressure transmission to bladder and proximal urethra
- also probably increases urethral resistance
- bladder neck repositoned to an intra-abdominal position and fixed with non-absorbable sutures from prepubic tendon to vagina


Describe urethropexy

- similar to colposuspension but sutures placed from urethra to prepubic tissues
- bladder neck relocated and fixed cranially


What are prostehtic sphincters?

- currently popular
- increase urethral resistance
- inflatable band placed around bladder neck
- filled with saline via SC port to acheive right amount of resistance
- allows post-op tweaks to achieve continence


How is collagen (or synthetic alternatives) used?

- injected into periurethral tissues to increase urethral resistance
- may be done at open surgery or via an endoscopic injector
- degraded over time


Name 2 sx tx options of SMI in male dogs

- Vas deference pexy
- prostatopexy


Describe vas deferens pexy

- sx to tx SMI in incontinent male dogs
- essentially a male 'colposuspension' using deferent ducts
- results obtained in UK not so good


Desvribe prostatopexy

- another essentially a male 'colposuspension' using prostate to pull bladder forward into abdominal cavity
- no complications reported


Sx options for ureteral ectopia

- re-inplantation of ureter: creation of neo-ureterocystostomy for intra-mural ureters (sx, laser ablation). Ureteral transection and re-implantation for extra-mural ureters
- ureteronephrectomy


2 techniques for neo-ureterocystotomy

intramural vs extramural (tunneling) technique


Complications - ectopic ureter re-implantation

- continued incontinence
- ascending infection and pyelonephritis
- bladder oedema and dysuriaa
- stenosis of new stoma
- recanalisaiton of ligated distal ureter
- wound breakdown


Other sx tx for urinary incontinence

- correction of congenital genito-urinary malformations
- tx of prostatic dz (omentalisation, others)
- excision of bladder, urethral and vaginal masses
- permanent cystostomy (palliative, choose owner/ patient carefully)


Define urinary incontinence

involuntary passage of urine


How might you adjust medications for refractory cases of SMI? (REFERENCE ONLY)

- increase dose of PPA (off license): TID dosing, watch for hypertension, irritability, anorexia, combine PA with estriol therapy
- IMIPRAMINE: improves bladder storage function, apha adrenergic effects, anecdotally helps in some dogs
- GnRH ANALOGUES: causes FSH and LH to fall, have been used successfully for management of refractory incontinence


Medical options - neurogenic/atonic bladder

- DRUGS TO REDUCE URETHRAL TONE: phenoxybenzamine, diazepam
- DRUGS TO IMPROVE BLADDER TONE/CONTRACTILITY: bethanecol (only once bladder easily expressed)
- PHYSICAL BLADDER EMPTYING: abdominal pressure, intermittent/ indwelling catheterisation, permanent cystostomy tube.