Urethral Obstruction in the Male Dog and Cat

Question 1

List some causes of urethral obstruction

Answer 1

Urethritis
Urethral/bladder neck neoplasia
Prostatomegaly (although much less common than in people)
Urethral Spasm

Question 2

What is FLUTD

Answer 2

Feline lower urinary tract disease

Question 3

What are crystals in urine are not always abnormal

Answer 3

Struvite, Amorphous phosphate and calcium oxalate are normal (particularly in stored urine)

Question 4

What crystals in urine are abnormal

Answer 4

Cystine, Xanthine and Urate crystals are abnormal

Question 5

3 ingredients needed for a stone

Answer 5

Organic matrix, supersaturated urine and a nidus

Question 6

Supersaturation depends on?

Answer 6

Urine pH
Urine concentration/specific gravity
Diet, water intake and infection determine these factorsA

Question 7

Alkaline urine causes what kind of stones

Answer 7

Struvite

Question 8

Acidic urine causes what kind of stones

Answer 8

Calcium oxalate

Question 9

Most common stones in canine and feline

Answer 9

Struvite
Calcium Oxalate
Urate

Question 10

What dog breed is predisposed to having urate stones

Answer 10

Dalmatian, bulldog, Russian terrier.

Question 11

Suggest why struvite stones occur

Answer 11

In dogs often associated with urease-producing bacteria
Commonly Staphylococcus spp or Proteus sppv
Neutral to Alkaline urine pH

Question 12

Suggest why Calcium oxalate uroliths occur

Answer 12

Chronic renal disease
Hypercalcemia – hyperparathyroidism/neoplasia
Urine pH acid to neutral

Question 12

Are struvite stones radioopaque or radiolucent

Answer 12

Opaque

Question 13

Are calcium oxalate uroliths radioopaque or radiolucent

Answer 13

Opaque

Question 14

Suggest why Purine Uroliths occur

Answer 14

liver dysfunction (porto-systemic shunts)
Congenital disrupted uric acid metabolism. Autosomal recessive condition.

Question 15

What cat breeds are predisposed to urate/purine stones

Answer 15

Siamese, Egyptian Mau, Birman

Question 16

Clinical signs of Urethroliths

Answer 16

LUT inflammation or urethral obstruction

Question 17

Clinical signs of Urocystoliths/cystic calculi (bladder)

Answer 17

Haematuria, recurrent UTI, LUT inflammation, asymptomatic

Question 18

Clinical signs of Ureteroliths

Answer 18

azotaemia/uraemia, abdominal pain, non-specific signs, asymptomatic

Question 19

Clinical signs of Nephroliths (kidney)

Answer 19

azotaemia/uraemia, haematuria, abdominal pain, non-specific signs, recurrent UTIs, asymptomatic

Question 20

Difference between ureteroliths vs urethroliths

Answer 20

Ureteroliths are stones in the ureters, urethroliths are stones in the urethra

Question 21

Urolithiasis - diagnosis

Answer 21

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.

Question 22

Difference between plain radiography vs contrast retrograde urethrogram

Answer 22

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.

Question 23

Do i draw hindlegs backwards or forwards to take a plain radiograph of urethra

Answer 23

Draw legs forward for urethral view

Question 24

Should contrast be given before or during Contrast retrograde urethrogram

Answer 24

During

Question 25

Urolith management (not obstructed)

Answer 25

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.

Question 26

Why Medical dissolution may not be suitable for all patients

Answer 26

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

Question 27

Managing struvite cyrstals

Answer 27

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.

Question 28

Urolith prevention

Answer 28

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.

Question 29

What is the most common cause of cystitis and urethral obstruction in the cat

Answer 29

Feline Idiopathic Cystitis

Question 30

Neutered females most likely to present with urethral obstruction (T/F)

Answer 30

False. Neutered Males!

Question 31

Risk factors for Feline Idiopathic cystitis

Answer 31

Overweight
Inactive
Indoor household
Multicat household
Dry diet (reduced water intake)
Stress

Question 32

Presentations of FLUTD

Answer 32

Dysuria
Pollakuria
Stranguria
Haematuria
Acute severe non obstructed episodes
Chronic low grade non obstructed
Acute urethral obstruction (male)

Question 33

Management – Acute non obstructed FIC

Answer 33

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

Question 34

Management of Chronic FIC

Answer 34

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.