Incontinence in small animals Flashcards
1
Q
Categories - urinary incontinence
A
- neurogenic/ non-neurogenic
- by presenting sign: congenital, overflow, stress, urge, paradoxical, by response to tx, hormonal
- useful aid to problem solving but not dx
2
Q
Causes of juvenile canine incontinence
A
- ureteral ectopia
- congenital USMI
- genitourinary dysplasia
- bladder hypoplasia
- intersexuality
- pervious urachus
- neurological dz
- combinations of above.
3
Q
Causes of adult canine incontinence
A
- USMI
- prostatic dz
- neurological dz
- urogenital neoplasia
- fistulae
- bladder atony
- cystitis
- detrusor instability
- pelvic masses
- combinations/ others
4
Q
Define and decribe USMI
A
= 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
5
Q
Pathophysiology - USMI
A
- mutlfactorial aetiology
- medium-large breeds most commonly
- factors: anatomical, hormonal, environmental, unknown
6
Q
USMI - risk factors
A
- 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)
7
Q
Dx - USMIA
A
- 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
8
Q
USMI in mae dogs
A
- 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
9
Q
What is ureteral ectopia?
A
= 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)
10
Q
Describe differences between dog/cat ureteral ectopia
A
- dogs most likely to have an intramural ectopic ureter
- cats usually have extramural ectopic ureter
11
Q
CS - ureteral ectopia
A
- continued dribbling urinary incontinence
- may have severe scalding
- frequently associated with UTIs
- may have concomitant SMI
- may have other abnormalities (hydronephrosis, hydroureter, rarely ureterocoeles)
12
Q
Describe genitourinarydysplasia
A
- 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
13
Q
Other causes - urinary incontinence - 4
A
- 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.
14
Q
Approach - urinary incontinence
A
Hx –> PE –> clincail pathology (urine, investigate PUPD if present) –>trial tx if suspect USMI –> diagnostic imaging/ endoscopy
15
Q
Role of diagnostic imaging in urinary incontinence
A
- cause urinary incontinence
- result from incontinence
16
Q
What diagnostic imaging should be used?
A
- 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
17
Q
Outline endoscopy in urinary incontinence diagnosis
A
- 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
18
Q
Tx - urinary incontinence
A
- ideally based on definitive diagnosis
- without this tx is TRIAL and SYMPTOMATIC
- not necessarily undesirable provided owners understand this is the case
19
Q
Medical tx - urinary incontinence
A
- 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
20
Q
Medical tx - SMI in dogs
A
- Phenlypropanolamine = PPA (most effective)
- Ephedrine hydrochloride (cheaper)
»> both of above are alpha-adrenergic agonists
21
Q
Which disorders have sx options?
A
- 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
22
Q
Management pre-sx
A
- UTI and obesity to be managed 1st
- owners should be given realistic expectations as success not guaranteed
23
Q
Sx tx options for SMI
A
- 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
24
Q
Principles - sx for USMI
A
- improve pressure transmission to bladder neck
- increase urethral resistance
- or both
25
Q
What is colposuspension?
A
- 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
26
Q
Describe urethropexy
A
- similar to colposuspension but sutures placed from urethra to prepubic tissues
- bladder neck relocated and fixed cranially
27
Q
What are prostehtic sphincters?
A
- 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
28
Q
How is collagen (or synthetic alternatives) used?
A
- injected into periurethral tissues to increase urethral resistance
- may be done at open surgery or via an endoscopic injector
- degraded over time
29
Q
Name 2 sx tx options of SMI in male dogs
A
- Vas deference pexy
- prostatopexy
30
Q
Describe vas deferens pexy
A
- sx to tx SMI in incontinent male dogs
- essentially a male ‘colposuspension’ using deferent ducts
- results obtained in UK not so good
31
Q
Desvribe prostatopexy
A
- another essentially a male ‘colposuspension’ using prostate to pull bladder forward into abdominal cavity
- no complications reported
32
Q
Sx options for ureteral ectopia
A
- 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
33
Q
2 techniques for neo-ureterocystotomy
A
intramural vs extramural (tunneling) technique
34
Q
Complications - ectopic ureter re-implantation
A
- continued incontinence
- ascending infection and pyelonephritis
- bladder oedema and dysuriaa
- stenosis of new stoma
- recanalisaiton of ligated distal ureter
- wound breakdown
35
Q
Other sx tx for urinary incontinence
A
- 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)
36
Q
Define urinary incontinence
A
involuntary passage of urine
37
Q
How might you adjust medications for refractory cases of SMI? (REFERENCE ONLY)
A
- 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
38
Q
Medical options - neurogenic/atonic bladder
A
- 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.
