disorders of micturition stephen p. dibartola, dvm department of veterinary clinical sciences...

Disorders of micturitionDisorders of micturition

Stephen P. DiBartola, DVMStephen P. DiBartola, DVM

Department of Veterinary Clinical SciencesDepartment of Veterinary Clinical Sciences

College of Veterinary MedicineCollege of Veterinary Medicine

Ohio State UniversityOhio State University

Columbus, OH 43210Columbus, OH 43210

The Nephronauts

Disorders of micturitionDisorders of micturitionDisorders of micturitionDisorders of micturition

Normal and abnormal Normal and abnormal micturitionmicturition

Normal and abnormal Normal and abnormal micturitionmicturition

• Normal micturition (urination)Normal micturition (urination)• Filling phaseFilling phase

• Emptying phaseEmptying phase

• IncontinenceIncontinence• Loss of voluntary control of Loss of voluntary control of

micturition (urination)micturition (urination)

Micturition: Emptying phaseMicturition: Emptying phaseMicturition: Emptying phaseMicturition: Emptying phase

Micturition: Filling phaseMicturition: Filling phaseMicturition: Filling phaseMicturition: Filling phase

Micturition: Role of Micturition: Role of somatic nervous systemsomatic nervous system

Micturition: Role of Micturition: Role of somatic nervous systemsomatic nervous system

Disorders of micturitionDisorders of micturitionDisorders of micturitionDisorders of micturition

• Non-neurogenicNon-neurogenic

• NeurogenicNeurogenic

Non-neurogenic Non-neurogenic disorders of micturitiondisorders of micturition


• Hormone-responsive (?)Hormone-responsive (?)• Anatomic abnormalityAnatomic abnormality• Paradoxical (obstructive)Paradoxical (obstructive)• Post-prostatectomyPost-prostatectomy• Post-perineal urethrostomyPost-perineal urethrostomy• Urge incontinence with UTIUrge incontinence with UTI• Sphincter mechanism incompetenceSphincter mechanism incompetence

Hormone-responsive Hormone-responsive urinary incontinenceurinary incontinenceHormone-responsive Hormone-responsive urinary incontinenceurinary incontinence

• Estrogen-responsive in female Estrogen-responsive in female dogsdogs

• Testosterone-responsive in male Testosterone-responsive in male dogsdogs

• Same as sphincter mechanism Same as sphincter mechanism incompetence or an overlapping incompetence or an overlapping syndrome?syndrome?



• Anatomic abnormalityAnatomic abnormality• Ectopic ureter MOST commonEctopic ureter MOST common

• Others much less commonOthers much less common

Ectopic ureters in dogsEctopic ureters in dogsEctopic ureters in dogsEctopic ureters in dogs

• Young (< 1 year) at presentationYoung (< 1 year) at presentation• Female > MaleFemale > Male• Siberian huskies, Labrador Siberian huskies, Labrador

retrievers, Golden retrievers, retrievers, Golden retrievers, othersothers

• Unilateral (67%) or bilateral (33%)Unilateral (67%) or bilateral (33%)• Terminate in vagina or distal Terminate in vagina or distal

urethraurethra


• Usually diagnosed Usually diagnosed by excretory by excretory urography or urography or ultrasonographyultrasonography

• Urethrocystoscopy Urethrocystoscopy may be “gold” may be “gold” standard for standard for diagnosisdiagnosis

urethraurethra

NormalNormalureteralureteralopeningopening


Urethral lumenUrethral lumen

UnilateralUnilateral BilateralBilateral

Cannizzo, 2000Cannizzo, 2000


Fenestrations in ectopic ureters openings in Fenestrations in ectopic ureters openings in urethras of female dogs (Cannizzo, 2000)urethras of female dogs (Cannizzo, 2000)


• Often accompanied by other Often accompanied by other abnormalitiesabnormalities• HydroureterHydroureter• HydronephrosisHydronephrosis• Urethral sphincter mechanism Urethral sphincter mechanism

incompetenceincompetence• Bladder hypoplasiaBladder hypoplasia• Renal problems (pyelonephritis, Renal problems (pyelonephritis,

renal hypoplasia)renal hypoplasia)


• Surgery controls incontinence in Surgery controls incontinence in only 50% of affected dogsonly 50% of affected dogs

• Owner must be warned that many Owner must be warned that many affected dogs have coexisting affected dogs have coexisting sphincter mechanism incompetence sphincter mechanism incompetence and may remain incontinent after and may remain incontinent after surgical correctionsurgical correction

Primary sphincter mechanism Primary sphincter mechanism incompetence in dogsincompetence in dogs

Primary sphincter mechanism Primary sphincter mechanism incompetence in dogsincompetence in dogs

• Common in large breed spayed femalesCommon in large breed spayed females• Common breeds: Doberman, giant Common breeds: Doberman, giant

Schnauzer, Old English sheepdog, Schnauzer, Old English sheepdog, RottweilerRottweiler

• Maximum urethral closure pressure Maximum urethral closure pressure (MUCP) lower and functional profile (MUCP) lower and functional profile length (FPL) shorter on urethral length (FPL) shorter on urethral pressure profile (UPP) in affected dogspressure profile (UPP) in affected dogs

• Bladder neck positioned more caudally Bladder neck positioned more caudally on radiographson radiographs

Primary sphincter mechanism Primary sphincter mechanism incompetence: Role of intra-incompetence: Role of intra-

abdominal pressureabdominal pressure

Primary sphincter mechanism Primary sphincter mechanism incompetence: Role of intra-incompetence: Role of intra-

abdominal pressureabdominal pressure

• Intra-abdominal pressure Intra-abdominal pressure increases in lateral recumbencyincreases in lateral recumbency

• Increases in intra-abdominal Increases in intra-abdominal pressure cannot be transmitted pressure cannot be transmitted to bladder neck and proximal to bladder neck and proximal urethra if these structures are urethra if these structures are displaced caudallydisplaced caudally

Primary sphincter mechanism Primary sphincter mechanism incompetence: Treatmentincompetence: Treatment

Primary sphincter mechanism Primary sphincter mechanism incompetence: Treatmentincompetence: Treatment

• 90% of affected female dogs 90% of affected female dogs respond well to respond well to phenylpropanolamine (PPA)phenylpropanolamine (PPA)

• 60% respond to estrogens60% respond to estrogens

• Some require both PPA and Some require both PPA and estrogensestrogens

Refractory sphincter mechanism Refractory sphincter mechanism incompetence: Collagen injectionincompetence: Collagen injectionRefractory sphincter mechanism Refractory sphincter mechanism incompetence: Collagen injectionincompetence: Collagen injection

• 50% response rate50% response rate• Response may be improved by Response may be improved by

adding phenylpropanolamineadding phenylpropanolamine• Injections can be repeated with Injections can be repeated with

similar response ratesimilar response rate• ExpensiveExpensive• Requires technical expertiseRequires technical expertise

Refractory sphincter mechanism Refractory sphincter mechanism incompetence: Colposuspensionincompetence: ColposuspensionRefractory sphincter mechanism Refractory sphincter mechanism incompetence: Colposuspensionincompetence: Colposuspension

• Moves bladder neck cranially and Moves bladder neck cranially and lengthens urethralengthens urethra• Approximately 50% response rateApproximately 50% response rate• Response rate may be improved by Response rate may be improved by

addition of phenylpropanolamine in addition of phenylpropanolamine in some dogssome dogs• Complications: transient dysuria, Complications: transient dysuria,

suture breakdown with relapsesuture breakdown with relapse

Neurogenic urinary incontinenceNeurogenic urinary incontinenceNeurogenic urinary incontinenceNeurogenic urinary incontinence

• UMN (automatic) bladderUMN (automatic) bladder• Lesion cranial to S1-S3Lesion cranial to S1-S3

• Partial voiding (local reflex arc intact)Partial voiding (local reflex arc intact)

• High residual volumeHigh residual volume

• Difficult to express (“external” urethral Difficult to express (“external” urethral sphincter lacks UMN inhibition)sphincter lacks UMN inhibition)

• Loss of voluntary controlLoss of voluntary control

Neurogenic urinary incontinenceNeurogenic urinary incontinenceNeurogenic urinary incontinenceNeurogenic urinary incontinence

• LMN (autonomous) bladderLMN (autonomous) bladder• S1-S3 lesionS1-S3 lesion• Partial “emptying” when Partial “emptying” when

intravesical/intra-abdominal pressure intravesical/intra-abdominal pressure exceeds elasticity of urethraexceeds elasticity of urethra

• Residual volume higher than UMN Residual volume higher than UMN bladderbladder

• Easy to express manuallyEasy to express manually• Loss of voluntary controlLoss of voluntary control

Reflex dyssynergy Reflex dyssynergy (reflex dyssynergia)(reflex dyssynergia)Reflex dyssynergy Reflex dyssynergy

(reflex dyssynergia)(reflex dyssynergia)

• Detrusor contracts but Detrusor contracts but urethral muscle fails to relaxurethral muscle fails to relax

Reflex dyssynergy: a diagnosis of Reflex dyssynergy: a diagnosis of exclusionexclusion

Reflex dyssynergy: a diagnosis of Reflex dyssynergy: a diagnosis of exclusionexclusion

• Middle-aged large to giant breed Middle-aged large to giant breed male dogsmale dogs• Watch dog urinate (normal stream Watch dog urinate (normal stream

initiation then dribbling and initiation then dribbling and tenesmus)tenesmus)• Pass urinary catheter to rule out Pass urinary catheter to rule out

mechanical obstructionmechanical obstruction• Measure residual urine volumeMeasure residual urine volume• Normal: < 0.4 ml/kgNormal: < 0.4 ml/kg• Dyssynergy: Often 20 ml/kg or moreDyssynergy: Often 20 ml/kg or more

Reflex dyssynergy: TreatmentReflex dyssynergy: TreatmentReflex dyssynergy: TreatmentReflex dyssynergy: Treatment• Phenoxybenzamine followed by bethanechol Phenoxybenzamine followed by bethanechol

if necessaryif necessary• Prazosin (specific alpha-1 blocker) followed Prazosin (specific alpha-1 blocker) followed

by bethanechol if necessaryby bethanechol if necessary• Diazepam or dantrolene if suspect striated Diazepam or dantrolene if suspect striated

muscle componentmuscle component• Intermittent catheterization as needed to Intermittent catheterization as needed to

maintain low residual volumemaintain low residual volume• Complications: bladder hyporeflexia, chronic Complications: bladder hyporeflexia, chronic

UTIUTI• Can be frustrating to manageCan be frustrating to manage

Disorders of micturition: HistoryDisorders of micturition: HistoryDisorders of micturition: HistoryDisorders of micturition: History

• SignalmentSignalment• Young animals Young animals Congenital Congenital

disordersdisorders• Middle-aged, medium to large Middle-aged, medium to large

breed female dogs breed female dogs Sphincter Sphincter mechanism incompetencemechanism incompetence

Disorders of micturition: HistoryDisorders of micturition: HistoryDisorders of micturition: HistoryDisorders of micturition: History

• Differentiate loss of voluntary Differentiate loss of voluntary control from behavior change or control from behavior change or PU/PDPU/PD

• Ask about hematuria or dysuriaAsk about hematuria or dysuria

• Ask about previous trauma or Ask about previous trauma or surgerysurgery

Disorders of micturition: Disorders of micturition: Physical findingsPhysical findings

Disorders of micturition: Disorders of micturition: Physical findingsPhysical findings

• Observe perineal region in Observe perineal region in females for wetness or odorfemales for wetness or odor

• Palpate bladder, urethra and Palpate bladder, urethra and prostate in malesprostate in males

• Perform vaginal exam in femalesPerform vaginal exam in females• Perform complete neurologic Perform complete neurologic

examinationexamination

Disorders of micturition: Disorders of micturition: Neurologic examNeurologic exam

Disorders of micturition: Disorders of micturition: Neurologic examNeurologic exam

• Anal toneAnal tone

• Bulbocavernosus reflexBulbocavernosus reflex

• Perineal reflexPerineal reflex

Disorders of micturition: Disorders of micturition: Other findingsOther findings

Disorders of micturition: Disorders of micturition: Other findingsOther findings

• Observe animal urinatingObserve animal urinating

• Pass urethral catheter to rule Pass urethral catheter to rule out mechanical obstructionout mechanical obstruction

• Collect and measure residual Collect and measure residual volume (normal, < 0.4 ml/kg)volume (normal, < 0.4 ml/kg)

Disorders of micturition: Disorders of micturition: Laboratory findingsLaboratory findings

Disorders of micturition: Disorders of micturition: Laboratory findingsLaboratory findings

• UrinalysisUrinalysis

• Urine culture and sensitivityUrine culture and sensitivity

• Contrast radiographyContrast radiography• Rule out anatomic abnormalityRule out anatomic abnormality

• UltrasonographyUltrasonography

Disorders of micturitionDisorders of micturitionSpecial procedures: CystometrogramSpecial procedures: CystometrogramDisorders of micturitionDisorders of micturitionSpecial procedures: CystometrogramSpecial procedures: Cystometrogram

• Pressure-Pressure-volume volume recording of recording of bladder’s bladder’s response to response to filling with filling with fluid or COfluid or CO22

Disorders of micturitionDisorders of micturitionSpecial procedures: Urethral pressure Special procedures: Urethral pressure profileprofile

Disorders of micturitionDisorders of micturitionSpecial procedures: Urethral pressure Special procedures: Urethral pressure profileprofile

• Pressure tracing Pressure tracing of urethra as of urethra as catheter is catheter is slowly slowly withdrawn from withdrawn from bladder at bladder at constant speedconstant speed

Urethral pressure profileUrethral pressure profileUrethral pressure profileUrethral pressure profile

• Maximum urethral pressure (MUP): Maximum urethral pressure (MUP): highest pressure recorded in urethrahighest pressure recorded in urethra

• Maximum urethral closure pressure Maximum urethral closure pressure (MUCP): difference between MUP and (MUCP): difference between MUP and intravesical pressureintravesical pressure

• Functional profile length (FPL): length Functional profile length (FPL): length of urethra over which urethral pressure of urethra over which urethral pressure exceeds intravesical pressureexceeds intravesical pressure

Urethral pressure profileUrethral pressure profileUrethral pressure profileUrethral pressure profile

FPL is most consistent; MUCP more variableFPL is most consistent; MUCP more variable

FPLFPLFPLFPL

MUCPMUCPMUCPMUCP

Micturition disorders: TreatmentMicturition disorders: TreatmentMicturition disorders: TreatmentMicturition disorders: Treatment

• Neurogenic: Correct lesion if Neurogenic: Correct lesion if possiblepossible

• Anatomic: Correct lesion if Anatomic: Correct lesion if possiblepossible

• Paradoxical: Relieve obstructionParadoxical: Relieve obstruction

• Urge: Treat UTIUrge: Treat UTI


• Hormone-responsive in femalesHormone-responsive in females• Diethylstilbestrol (DES) 0.1 to 1.0 mg Diethylstilbestrol (DES) 0.1 to 1.0 mg

PO PO 3-5 days followed by 1 mg PO 3-5 days followed by 1 mg PO q7dq7d• PremarinPremarin® 20 ® 20 g/kg PO q4d or 0.6 mg g/kg PO q4d or 0.6 mg

total dose q4dtotal dose q4d• Adverse effects: estrus, perineal Adverse effects: estrus, perineal

alopecia, bone marrow suppressionalopecia, bone marrow suppression


• Adrenergic agonists (urethral Adrenergic agonists (urethral smooth muscle stimulants)smooth muscle stimulants)• EphedrineEphedrine• Nonspecific agonist: Nonspecific agonist: > > • Dogs: 25-100 mg PO q12h to q8hDogs: 25-100 mg PO q12h to q8h• Adverse effects: CNS stimulation, Adverse effects: CNS stimulation,

tachycardia, hypertensiontachycardia, hypertension• Not used much due to adverse effectsNot used much due to adverse effects


• Adrenergic agonists (urethral Adrenergic agonists (urethral smooth muscle stimulants)smooth muscle stimulants)• Phenylpropanolamine (PPA)Phenylpropanolamine (PPA)

-adrenergic agonist-adrenergic agonist• Dogs: 1.5 mg/kg PO q12h to q8hDogs: 1.5 mg/kg PO q12h to q8h• Effective in 90% of dogs with sphincter Effective in 90% of dogs with sphincter

mechanism incompetencemechanism incompetence• Less CNS stimulation than ephedrine and Less CNS stimulation than ephedrine and

no significant effect on blood pressureno significant effect on blood pressure• Off the human marketOff the human market


• Adrenergic antagonists (urethral Adrenergic antagonists (urethral smooth muscle relaxants)smooth muscle relaxants)• PhenoxybenzaminePhenoxybenzamine• Non-specific Non-specific -adrenergic antagonist-adrenergic antagonist• 0.25 to 0.5 mg/kg q12h to q8h0.25 to 0.5 mg/kg q12h to q8h• Relaxes urethral smooth muscleRelaxes urethral smooth muscle• Adverse effect: hypotensionAdverse effect: hypotension• Used for functional outlet obstruction Used for functional outlet obstruction

(including reflex dyssynergy)(including reflex dyssynergy)


• Adrenergic antagonists (urethral Adrenergic antagonists (urethral smooth muscle relaxants)smooth muscle relaxants)• PrazosinPrazosin• Specific Specific -1 adrenergic antagonist-1 adrenergic antagonist• 0.1 mg/kg divided q8h0.1 mg/kg divided q8h• Relaxes urethral smooth muscleRelaxes urethral smooth muscle• Adverse effect: hypotensionAdverse effect: hypotension• Used for functional outlet obstruction Used for functional outlet obstruction

(including reflex dyssynergy)(including reflex dyssynergy)


• Adrenergic antagonists (urethral Adrenergic antagonists (urethral smooth muscle relaxants)smooth muscle relaxants)• AcepromazineAcepromazine• Phenothiazine with Phenothiazine with -adrenergic -adrenergic

antagonist effectsantagonist effects• 0.2 mg/kg SQ q12h or 1.25 mg total 0.2 mg/kg SQ q12h or 1.25 mg total

dose PO q24h for post-obstructive dose PO q24h for post-obstructive urethral spasm in catsurethral spasm in cats• Relaxes urethral smooth muscleRelaxes urethral smooth muscle• Adverse effect: hypotensionAdverse effect: hypotension


• Other non-specific smooth muscle Other non-specific smooth muscle relaxants used for detrusor relaxants used for detrusor hyperactivityhyperactivity• PropanthelinePropantheline• OxybutyninOxybutynin• FlavoxateFlavoxate• DicyclomineDicyclomine

Micturition disorders: TreatmentMicturition disorders: TreatmentSmooth muscle stimulantsSmooth muscle stimulantsMicturition disorders: TreatmentMicturition disorders: TreatmentSmooth muscle stimulantsSmooth muscle stimulants

• BethanecholBethanechol• Parasympathomimetic with primarily Parasympathomimetic with primarily

muscarinic effectsmuscarinic effects• Dogs: 5-15 mg PO q8hDogs: 5-15 mg PO q8h• Cats: 1.25-5 mg PO q8hCats: 1.25-5 mg PO q8h• Adverse effects: Anorexia, salivation, Adverse effects: Anorexia, salivation,

lacrimation, abdominal cramping, lacrimation, abdominal cramping, vomiting, diarrheavomiting, diarrhea• Used for detrusor hypoactivity, used in Used for detrusor hypoactivity, used in

conjunction with conjunction with -antagonist in reflex -antagonist in reflex dyssynergydyssynergy


• Striated muscle relaxantsStriated muscle relaxants• DiazepamDiazepam• Used to relax urethral striated muscleUsed to relax urethral striated muscle• Dog: 2-10 mg PO q8hDog: 2-10 mg PO q8h• Cat: 1-2 mg PO q8hCat: 1-2 mg PO q8h• CAUTION IN CATS: Hepatotoxicity may CAUTION IN CATS: Hepatotoxicity may

be observed when administered orallybe observed when administered orally• May have limited effect on feline urethral May have limited effect on feline urethral

striated musclestriated muscle


• Skeletal muscle relaxantsSkeletal muscle relaxants• DantroleneDantrolene• Direct-acting striated muscle Direct-acting striated muscle

relaxantrelaxant• Used for urethral striated muscle Used for urethral striated muscle

spasmspasm• Dog: 1-5 mg/kg PO q12h to q8hDog: 1-5 mg/kg PO q12h to q8h• Adverse effects: HepatotoxicityAdverse effects: Hepatotoxicity

disorders of micturition stephen p. dibartola, dvm department of veterinary clinical sciences...

Documents

disorders of micturition

common slide

nephronauts slide

filling phase slide

emptying phase slide

renal hypoplasia slide

distal urethra slide

dogs fenestrations