Micturition Disorders

Question 1

urinary incontinence

Answer 1

passive leakage of urine WITHOUT voluntary control or sense of urgency

Question 2

pollakiuria

Answer 2

passive leakage of urine WITH voluntary control or sense of urgency

Question 3

ddx for urinary incontinence

Answer 3

storage vs voiding
storage: ectopic ureters, USMI, overactive bladder secondary to UTI/neoplasia/infection etc

voiding: urethrolith, neoplasia, proliferative urethritis, iFUOTO

Question 4

ddx for pollakiuria

Answer 4

UTI
uroliths
neoplasia
foreign body
foreign body
polypoid cysts

Question 5

sympathetic pathway on urination

Answer 5

stimulates passive urine retention

L1-L4 –> caudal mesenteric ganglia –> hypogastric nerve –> NE –>
- beta receptors (bladder) –> relaxation
- alpha receptors (internal urethral sphincter) –> contraction

Question 6

parasympathetic pathway on urination

Answer 6

stimulates urine release

S1-S3 –> pelvic nerve –> acetylcholine –> muscarinic receptors in detrusor muscle –> bladder contraction

Question 7

somatic pathway on urination

Answer 7

conscious urine retention

S2-4 –> pudendal nerve –> acetylcholine –> nicotinic receptors in external urethral sphincter –> EUS contraction

Question 8

storage disorders & PVRV & ddx

Answer 8

ALWAYS cause urinary incontinence

causes a NORMAL post void residual volume

ddx:
- ectopic ureters
- USMI
- detrusor instability

Question 9

voiding disorders & PVRV & ddx

Answer 9

MAY cause urinary incontinence

causes an INCREASED post void residual volume

ddx:
- functional outflow obstruction
- mechanical outflow obstruction
- atonic bladder

Question 10

do storage or voiding disorders cause stranguria in additional to urinary incontinence

Answer 10

voiding disorders

Question 11

diagnostics to perform on urinary incontinent patients

Answer 11

1. PE - record PVRV by measuring bladder size before and after urination on US
2. UA - evaluate USG to differentiate from PU/PD, if bacteriuria + pyuria –> culture
3. Urine Culture - only treat positive clinical cultures; if signs don’t resolve, pursure other diagnostics
4. Ultrasound - evaluate for anatomic abnormalities (ectopic ureters)

Question 12

ectopic ureters

Answer 12

congenital abnormal insertion of the ureters into the lower urinary tract

Question 13

signalment for ectopic ureters

Answer 13

dogs
young (>1 ur)
female > males

huskies, labs, goldens

Question 14

are most ectopic ureters intra or extramural and uni or bilateral

Answer 14

bilateral
intramural

Question 15

what is the best first line diagnostic for evaluating a urinary incontinent dog

Answer 15

ultrasound

if normal on US –> refer for cystoscopy

Question 16

what is the gold standard diagnostic for ectopic ureters

Answer 16

cystoscopy
able to treat intramural ureters with laser ablation at time of diagnosis

Question 17

treatment for ectopic ureters

Answer 17

laser ablation (intramural)

cystotomy (extramural)

Question 18

urethral sphincter mechanism incompetence (USMI)

Answer 18

“stress” incontinence
- considered a functional storage disorder

Question 19

USMI signalment

Answer 19

urinary incontinence in a HEALTHY dog with a normal neurologic exam

larger breeds
obese
post-spay

Question 20

diagnosis of USMI

Answer 20

primarily made on signalment and clinical signs

rule out neurologic disorder with neuro exam

1. UA and culture
2. UPP (not routinely performed)

Question 21

USMI treatment

Answer 21

medical:
1. alpha adrenergic agonists
(PPA - pheynlopropanolamine)
2. estrogen (incurin)

surgical
1. urethral bulking agents (collagen)
2. urethral occluders

Question 22

alpha agonists MOA

Answer 22

stimulates contraction of the internal urethral sphincter by increasing NE release and decreasing NE reuptake

Question 23

side effects of adrenergic agonists

Answer 23

SNS stimulation
- restlessness
- anxiety
- aggression
- hypertension
- tachycardia

Question 24

estrogen MOA

Answer 24

increase receptor sensitivity to estrogen receptors in the transitional epithelium of the proximal urethra

Question 25

urethral bulking agents

Answer 25

bovine collagen injection of collagen into the bladder wall around the urethral sphincter to decrease lumen size used only if failure of PPA and estrogen

Question 26

urethral occluders

Answer 26

external mechanical occlusion around the urethra hydraulic occluder attached to a subcutaneous port --> can inflate the occluder using the vascular port

Question 27

detrusor instability

Answer 27

non-neurologic associated bladder hyperexcitability idiopathic is UNCOMMON - likely has an inflammatory disease going on that causes the bladder to be overactive

Question 28

DDX for OAB

Answer 28

- uti - urothelial carcinoma - prostatitis - proliferative urethritis - polypoid cystitis - foreign body

Question 29

treatment for TRUE idiopathic OAB

Answer 29

anticholinergics (antimuscarinics) - tolterodine - oxybutynin must rule out all underlying causes (bacterial cystitis, stones, neoplasia, etc)

Question 30

anticholinergic MOA

Answer 30

blocks PNS stimulation of the detrusor muscle --> prevention of contraction

Question 31

types of voiding disorders

Answer 31

mechanical: urethroliths, neoplasia, urethritis functional: idiopathic functional urinary outflow tract obstruction (iFUOTO) neurologic: upper motor neuron bladder (ex. disc disease affecting the hypogastric nerve - unable to shut off the SNS when time to void --> voiding against a contracted internal urethral sphincter)

Question 32

diagnostic workup of voiding disorders

Answer 32

1. rule out mechanical obstruction: radiographs, cystourethrogram, cystoscopy, abdominal US 2. rule out neurologic: neuro exam 3. rule in IFUOTO - high PVRV, can do urethral pressure profile

Question 33

treatments for voiding disorders

Answer 33

mechanical: relieve obstruction functional: alpha antagonists (flomax)

Question 34

alpha antagonists

Answer 34

tamsulosin (flomax) blocks alpha adrenergic receptors in the urethral sphincter --> prevents SNS stimulation of contraction --> relieves obstructed sphincter

Question 35

side effects of alpha antagonists

Answer 35

weakness, lethargy, hypotension