Urethral Obstruction in the Male Dog and Cat Flashcards
List some causes of urethral obstruction
Urethritis
Urethral/bladder neck neoplasia
Prostatomegaly (although much less common than in people)
Urethral Spasm
What is FLUTD
Feline lower urinary tract disease
What are crystals in urine are not always abnormal
Struvite, Amorphous phosphate and calcium oxalate are normal (particularly in stored urine)
What crystals in urine are abnormal
Cystine, Xanthine and Urate crystals are abnormal
3 ingredients needed for a stone
Organic matrix, supersaturated urine and a nidus
Supersaturation depends on?
Urine pH
Urine concentration/specific gravity
Diet, water intake and infection determine these factorsA
Alkaline urine causes what kind of stones
Struvite
Acidic urine causes what kind of stones
Calcium oxalate
Most common stones in canine and feline
Struvite
Calcium Oxalate
Urate
What dog breed is predisposed to having urate stones
Dalmatian, bulldog, Russian terrier.
Suggest why struvite stones occur
In dogs often associated with urease-producing bacteria
Commonly Staphylococcus spp or Proteus sppv
Neutral to Alkaline urine pH
Suggest why Calcium oxalate uroliths occur
Chronic renal disease
Hypercalcemia – hyperparathyroidism/neoplasia
Urine pH acid to neutral
Are struvite stones radioopaque or radiolucent
Opaque
Are calcium oxalate uroliths radioopaque or radiolucent
Opaque
Suggest why Purine Uroliths occur
liver dysfunction (porto-systemic shunts)
Congenital disrupted uric acid metabolism. Autosomal recessive condition.
What cat breeds are predisposed to urate/purine stones
Siamese, Egyptian Mau, Birman
Clinical signs of Urethroliths
LUT inflammation or urethral obstruction
Clinical signs of Urocystoliths/cystic calculi (bladder)
Haematuria, recurrent UTI, LUT inflammation, asymptomatic
Clinical signs of Ureteroliths
azotaemia/uraemia, abdominal pain, non-specific signs, asymptomatic
Clinical signs of Nephroliths (kidney)
azotaemia/uraemia, haematuria, abdominal pain, non-specific signs, recurrent UTIs, asymptomatic
Difference between ureteroliths vs urethroliths
Ureteroliths are stones in the ureters, urethroliths are stones in the urethra
Urolithiasis - diagnosis
Clinical signs (recurrent UTIs, persistent hematuria/pollakiuria)
Urinalysis reveals hematuria, proteinuria, and crystalluria, with evidence of urinary tract infection.
Urine culture assesses the predisposition to UTIs in the presence of uroliths.
Diagnostic imaging, preferably radiographs, is recommended over ultrasound.
Radiographs allow assessment of size and number of stones; not all stones may be radiodense.
Contrast may be needed for stones that are not radiodense.
Ultrasound may cause distal acoustic shadowing, making it challenging to determine the exact number of stones.
Difference between plain radiography vs contrast retrograde urethrogram
Plain radiography uses X-rays to provide a general image of the urinary system, while contrast retrograde urethrogram involves introducing a contrast agent into the urethra for detailed imaging of its structure and identification of specific conditions.
Do i draw hindlegs backwards or forwards to take a plain radiograph of urethra
Draw legs forward for urethral view
Should contrast be given before or during Contrast retrograde urethrogram
During
Urolith management (not obstructed)
Spontaneous voiding or catheter retrieval for small stones in female dogs, voiding urohydropropulsion for smaller stones in dogs, while options for larger stones involve lithotripsy (limited availability), surgery (including minimally invasive techniques), or medical/dietary dissolution depending on stone composition.
Why Medical dissolution may not be suitable for all patients
Specifically applicable to struvite, urate, and cysteine stones but only for stones in the renal pelvis or bladder; contraindications include obstruction, high risk of unmonitored obstruction, and patient discomfortM
Managing struvite cyrstals
Dietary modification involves reducing urinary pH, excretion of Mg2+ & PO42-, and urine concentration.
Urinary acidification with ammonium chloride may be employed.
Infection-induced Struvite:
If signs of cystitis are present, administer 7 days of antibiotic treatment.
If no signs, culture urine, and treat if Staph pseudointermedius/Proteus sp. is isolated; dietary modification includes reducing urinary pH, Mg2+ & PO42- excretion, urine concentration, and urea production.
Urolith prevention
eliminating underlying causes, minimizing risk factors, and setting goals such as no crystals in urine and specific gravity levels below 1.020 in dogs and 1.025 in cats. Achieving these goals includes strategies like increasing water intake, voiding frequency, and potentially incorporating dietary modifications or drug therapy, but caution is necessary as preventing one type of urolith may predispose to another.
What is the most common cause of cystitis and urethral obstruction in the cat
Feline Idiopathic Cystitis
Neutered females most likely to present with urethral obstruction (T/F)
False. Neutered Males!
Risk factors for Feline Idiopathic cystitis
Overweight
Inactive
Indoor household
Multicat household
Dry diet (reduced water intake)
Stress
Presentations of FLUTD
Dysuria
Pollakuria
Stranguria
Haematuria
Acute severe non obstructed episodes
Chronic low grade non obstructed
Acute urethral obstruction (male)
Management – Acute non obstructed FIC
Generally self limiting- Improves in 2-4days and resolved in 1 week
Provide analgesia
- Buprenorphine (trans-mucosal)
- NSAIDS
- Gabapentin
- Maropitant
Warn owners can be recurrent
NO indication for antibiotics unless you confirm bacteria in the urine
Management of Chronic FIC
Dietary modification using urinary diets, increasing water intake, and gradually changing diets; address stress and behavioral factors with multimodal environmental modifications, considering household dynamics and possible referral to a behaviorist.
