Urinary Incontinence COPY Flashcards
Define incontinence
The inability to control urination with the involuntary passage of urine
What is often the clinical presentation of incontinence?
“My dog is leaving puddles on the floor”
“He’s weeing all the time”
“She’s begging to go out more at night”
“He smells of urine”
“She’s having trouble peeing”
Name some possible causes of inappropraite uriantion
•Many causes including:
- metabolic disorders (polyuria)
- behavioural problems
- musculoskeletal problems
- congenital defects
- neurological problems
- urethral incompetence
•Most of these you have covered elsewhere in the course
Name some metabolic disorders that can cause polyuria?
- Renal
- Hepatic
- Endocrine – diabetes mellitus, diabetes insipidus, hyperthyroidism, hyperadrenocorticism, hypoadrenocorticism
- Infectious – pyelonephritis, pyometra
- Electrolytes – hypokalemia, hypercalcaemia
- Iatrogenic – diuretics, steroids etc
If you suspect there is a metabolic disorder causing the PU, what should you do?
- History/clinical signs should raise suspicion (most of these disorders cause a whole spectrum of problems).
- Check if actually polydipsic if this is reported!! Get them to record the amount of water in 24h
- Clinical pathology (routine biochemistry, haematology and urinanalysis) is going to be the main tool for differentiating these
- Manage according to the individual problem
- You should eliminate these causes before looking at other options
What are some PU related behavioural problems in cats?
- Territorial marking (spraying) vs litter box problems
- FLUTD
- You need to look at changing the environment (stressors, litter trays, boredom, water intake)
- Pheromonal sprays? (Feliway)
- FLUTD – environmental issues are also important, need to address the environment as much as anything else
What are some PU related behavioural problems in dogs?
- Housetraining
- Separation anxiety
- Behaviour modification is required in most cases
- Pheromonal therapy? (DAP)
- Psychotropic drugs (serotonergic or dopaminergic agents) may help as adjunct to behaviour modification
How can lower urinary tract inflammation cause PU?
How can you help diagnose this?
- Increased frequency and urgency may be mistaken for incontinence
- Good history and urinalysis should help diagnose, plus response to antibiotic treatment if infection present
- BUT, remember animals with structural abnormalities are prone to secondary UTIs
How can MSK problems cause PU related issues? Give 3 examples
- If you can’t physically manage to lift your leg/use your litter box it’ll affect your ability to control your urination
- Obesity
- Arthritis
- Pain/Injury
- A thorough physical exam and history should suggest this cause
- Managed through weight loss/exercise modification
- Pain relief (Non steroidal anti-inflammatory medication)
- Animals with pelvic fractures may need help to go to the toilet
What is the detrusor reflex?
Increased vesicular pressure with filling achieves threshold resulting in contraction of the detrusor muscle. Sensory stimulation and causes bladder to contract – combined with syma0thetic and voluntary control to relax sphicnters, so inhibitor of sympathetic stimulation of the bladder, allow internal urethral sphincter to open and then voluntarily, we open external sphincter
What is the micturition relfex?
Combination of detrusor reflex with inhibition of sympathetic and voluntary motor supply to the bladder and urethra
Briefly outline the neurogenic bladder i.e. how is it controlled?
- Neurological problems are an important cause of incontinence
- Innervation of bladder from 2 main locations in the spine. Cranial lumbar area, sympathetic stimulation and in caudal pelvic and sacral area
- Cranial – sympathetic, beta adrenergic receptors going to muscle – INHIBITORYS and STOPS FROM CONTRACTING. Alpha to urethral sphincter which is positive and causes to close
- Caudally in sacral – parasympathetic and somatic and sensory info form bladder, detects stretching. Lead to actual contraction of the detrusor muscle and somatic stimulation is voluntary control and is through pudendal nerve and will hold closed external urethral sphincter
What do we see with LOWER motor neuron disorders?
Lower motor neuron disorders:
- Damage to the sacral spine/pelvic plexus
- Absent voluntary micturition
- Atonic bladder
- Atonic urethral sphincters
- Absent detrusor reflex
- Concurrent reduced perineal reflex and anal tone
- The bladder will be flaccid and easy to express
What do we see with UPPER motor neuron disorders?
Upper motor neuron disorders:
- Damage to brain or higher spinal cord
- Absent voluntary micturition
- Increased urethral sphincter tone
- High volume urinary retention
- Development of automatic bladder
- Bladder is hard to express
What is the standard bladder care of the spinal patient?
- Catheterisation post surgery in most cases
- Urinary tract infection is a common complication
- Catheterisation longer term may be necessary if the animal dribbles constantly
- An automatic bladder may develop (fills and empties under local reflex control as in the neonate)
- Putting external pressure on the bladder may trigger emptying
- Regular (4 times daily) expression will help prevent overflow/over-distension and urinary tract infection
- The owner can be taught to do this at home
- You must discuss with them in depth and demonstrate it
- If at all possible you don’t want to have a catheter in long term
- Being covered in urine or unable to urinate is a major welfare problem with long term care of spinal patients (and a major cause of euthanasia)
- Remember they may be also faecally incontinent
What physical damage can cause problems to the bladder?
- Trauma/neoplasia/post surgery
- May be direct interference with outflow or sphincter mechanism
- Secondary to obstruction (blocked cat or dog) – overstretched bladder, becomes atonic (“detrusor areflexia or paralysis”)
- Secondary to tail stretch (or other injury) – neurological effects
What is the treatment of the neurogenic bladder?
- Some will improve with time (most won’t)
- Can try drugs (often a poor response) e.g.
–Smooth/skeletal muscle relaxants (e.g. prazosin, diazepam) for those that are hard to express
–Cholinergic agents (e.g. bethanacol) for those that are atonic
An uncommon neurological causes of incontinence is Detrusor-urethral (“Reflex”) dyssynergia (rare). What is this? How might it be characteristic initially?
–Initiation of detrusor reflex with reflex contraction of the urethral sphincter
–Results in bladder contracting against markedly increased outlet pressure
–May be neurological damage or idiopathic
–Characteristically initiate urine stream that quickly dries up
–Initial alpha-antagonists (e.g. ACP, prazosin) – not long term
–Catheterisation short term (or daily long term if does not settle?)
What can cause overflow incontinence?
- May occur with atonic bladder
- With urethral obstruction and secondary urinary retention, when pressure in bladder overcomes obstructive resistance, e.g. urolithiasis, neoplasia, prostatic disease
What is iatrogenic incontinence?
How can it be diagnosed?
- Inadvertent inclusion of part of urinary tract in ligature at surgery, usually spay
- Fistula forms between ureter/bladder and vaginal stump, so urine drains into vagina
- Incontinence develops soon after surgery
- Can be diagnosed by contrast radiograph
What is a common cause of male incontinence?
•Prostatic disease in male dogs
–Common cause of male incontinence
–Any incontinent male dog should be investigated for prostatic disease
What is the most common non-neurogenic cause of canine incontinence?
Urethral Sphincter Mechanism Incompetence
What is the typical case for a patient with a urethral Sphincter Mechanism Incompetence?
Which breeds is it more common in?
- Typical case = older, spayed bitch
- More common in female than male (shorter urethras)
- More common in large/giant breeds
- May be congenital (much less common)
- Uncommon in cats
What factors may be involved in urinary sphincter mechanism incompetence?
Several factors may be involved:
- Ageing or lack of oestrogen cause changes in urethral support structures (collagen)
- Abnormal position of bladder or urethra (“intra-pelvic bladder”)
- Reduced amount of smooth muscle in the urethra
- Relative lack of oestrogen reduces urethral tone
- Obesity
- Breed predispositions (genetic factors?)
Major systematic review stated evidence not strong enough to determine link between neutering or age of neutering and urinary incontinence in bitche
How is USMI diagnosed?
How is it mostly managed?
- Very common condition
- Diagnosis usually made by a combination of:
–Signalment
–Elimination of other causes of incontinence (i.e. otherwise healthy, neurologically normal dog with concentrated urine and no LUT inflammation)
–Response to therapy
- Incontinence may be intermittent, e.g. only on some days
- Most managed medically
- Medical treatment regimes are designed to increase urethral sphincter ton
Name some drugs that can be used to treat USMI?
Sympathomimetic agents:
Phenylpropanolamine (e.g. “Propalin”, “Urolin”)
- good, rapid response
- 3 doses/day
- can use in male dogs/cats
Possible adverse effects: restlessness, aggression, tachycardia, weight loss
Oestrogens
Estriol (“Incurin”, “Enurace”)
- longer to get a response
- 1 dose/day
- cannot use in males/entire bitches/cats
Adverse effects: oestrogenic effects
Don’t forget – adjunctive treatments such as weight reduction
What is most effective in the treatment of USMI?
- 85-90% will improve with sympathomimetics
- 40-65% with oestrogens
- Can try combination therapy if one agent alone isn’t working
- Dogs can become refractory to treatment over time
- Surgical treatment for refractory cases
How can USMI be treated with surgery?
•Surgical options
–Not day 1 competency …..
–Approx. 50% will become continent
•Techniques to make the bladder/urethra hang better in the abdomen:
- Colposuspension (suspending the urethra in a “sling” of vagina)
- Urethropexy (fixing the urethra intrabdominally)
•Techniques to make the lumen of the urethra smaller
- Submucosal urethral injections of bulking agents (e.g. collagen)
- Artificial urethral sphincter cuff placement
A dog is suffering from a neurogenic bladder that is very hard to express. What is the best treatment?
Relaxing agents e.g. diazepam
What is the typical profile of dogs with USMI? Choose all that apply
Older, large breeds, female
What is the usual initial line of management for bitches with USMI?
- Patient/environmental management
- Medical
What is the best initial medical treatment option for bitches with USMI?
•Sympathomimetic agents (e.g. phenylpropanolamine) as will increase tone
