Contributors: Kyle Braund, Kathy Lunn, Julien Bazelle

 Species: Canine   |   Classification: Miscellaneous

Introduction

  • Dysuria is defined as painful and/or difficult urination.
  • Clinical evaluation of urinary function can be accomplished by a series of diagnostic procedures.
  • Physical examination and a complete history of the patient are important in the diagnosis of urinary tract disease.
  • Observation of the patient during urination is very helpful.
  • Signs may be due to urinary tract disease or extra-urinary structures impinging on urinary tract.

Is it likely that the patient has urinary tract disease?
Signalment

Clinical signs

  • Non-productive straining.
  • Signs of pain while urinating.
  • Hematuria Hematuria.
  • Frequent attempts to urinate.
  • Passage of small amounts of urine.
    Care not to confuse fecal tenesmus with urinary straining.
  • Systemic signs:
    • Depression, vomiting, anorexia (if obstructed).
    • Constipation or straining to defecate.

Clinical examination

  • Palpation of bladder size and shape:
    • Palpate urethra per rectum.
    • Empty bladder may indicate poor filling, bladder irritation or reflex dyssynergia.
    • Large bladder may indicate outflow obstruction.
  • Palpation of prostate for evidence of enlargement Prostate gland: clinical examination.
  • Palpate bladder before and after urination.
  • Observe urine stream during urination.

Causes of dysuria

Inflammation or infection

Obstruction

Urinary tract trauma

Further investigation

  • Try to answer the following questions:
    • Is there evidence of difficulty urinating?
    • Is there difficulty with defecation?
    • Is there ever normal urine voiding?
    • Is the frequency of micturition attempts increased?
    • Is there obstruction to urine outflow?
    • Is total amount of urine production normal?
    • Is the urine color normal?
    • Is there evidence of incontinence?
  • In all cases of dysuria, attempts should be made to pass a urethral catheter if the bladder is full on examination.
  • In functional (neurogenic) obstruction, the catheter should pass easily and the bladder can be drained.
    Exercise great caution when passing a catheter in an animal with potential urethral obstruction as force can result in urethral rupture.

Imaging

Radiography

  • Useful to determine size and position of bladder Radiography: abdomen Radiography: cystography :
    • Small supports diagnosis of inflammation and increased micturition.
    • Large suggests outflow obstruction.
  • Assess extra urinary tract structures for abnormalities, eg prostate.
  • May reveal urolithiasis.
  • Evaluate sublumbar lymph nodes.
  • Evaluate pelvis and spine.
  • Assess size of kidneys and ureters in case of severe and often chronic obstruction Radiology: lower urinary and genital tracts. 

Contrast radiography

Endoscopy

Ultrasonography

Laboratory investigation

Urinalysis

Remember that a voided urine sample will not help to localize the site of inflammation.

Urine culture

Cytological examination

  • Of urine sediment Urinalysis: centrifuge sediment , prostatic wash Cytology: prostatic wash or ejaculate for evidence of neoplasia.
  • Prostatic wash Prostate flush. 
  • Fine needle aspirate of prostate (percutaneous +/- ultrasound guidance) Biopsy: prostate ) if the prostatic wash is not diagnostic. 
  • Also look for crystals which may be seen if uroliths are present, but crystals alone do not confirm or definitively identify urolithiasis.

Blood samples

  • Always check renal function Renal function assessment in animals with lower urinary tract disease.
  • Post-renal azotemia Azotemia may be present in cases with urinary tract obstruction.

Prognostic indicators

  • Bladder distension can result in stretching of tight junctions (this can become irreversible).
  • Prolonged back pressure on the kidneys due to urethral obstruction can result in acute renal failure Kidney: acute kidney injury (AKI) and permanent renal damage.
  • Renal damage may result from chronic urinary tract infections which may result from lower urinary tract disease.
  • Urethral stricture can occur after severe urethral trauma, for example after obstruction.