06 - urolithiasis

Question 1

1. what causes urolithiasis?

Answer 1

1. when urine is oversturated with minerals in susc individuals

Question 2

uroliths may be present withough crystals, crystals may be present without forming uroliths

Question 3

(risk factors)

1. urine pH can promote or inhibit crystal formation
2. metabolic dz
3. breed, gender, age, diet
4. once initiaion of urolith formation has occurred, the nidus must be retained within the urinary tract, and conditions must be favorable to promote growth of the urolith

Question 4

(pathophysiology)

1. urethral obstruction
2. irritation of bladder mucosa -> inflammation and cystitis
3. caculi can serve as substrate for bacteria, leading to difficulty resolving bacterial UTI

Question 5

(history and Cx)

1. Cx?
2. some uroliths may be passed in the urine

Answer 5

1. hematuria, stranguria, dysuria, and pollakiuria

Question 6

(dx)

1. consider predisposing factors (history, systemic dz)
2. px - stones may be palpable
3. UA
4. crystalluria NOT helpful
5. radiographs
6. Ultrasound - can identify regardless of radioopacity

Question 7

what 3 types are radioopaque?

Answer 7

struvite, calcium oxalate, calcium phosphate

Question 8

(tx)

1. sx if repeated obstruction
2. urohydropropulsion
3. if using medical dissolution, continue tx how long?

Answer 8

3. 1 month past radiographic resolution

(if no improvement after 4 to 6 weeks -> should consider sx)

Question 9

get pictures of the stones from somewhere

both radiograph and live….

figure this out!

Question 10

(prevention of uroliths)

(general)

1. most can recur
2. increase water intake

Question 11

what is the most common urolith in dogs?

Answer 11

struvite (triple phosphate)

Question 12

(struvite uroliths)

1. most common urolith in dogs
2. more likely to form in what kind of urine (pH)?
3. what kind of bacteria are required for infection induced struvite?
4. what kind of diet ^ risk?

Answer 12

2. alkaline and infected
3. urease producing
4. diets high in protein, magnesium, and phosphorus

Question 13

(struvite uroliths)

(tx)

1. for sterile?
2. for infection induced?

Answer 13

1. protein and magnesium restriction, acidic urine
2. abx + same for sterile

Question 14

(calcium oxalate uroliths)

1. occurs with what pH?
2. risk factors?
3. tx?

Answer 14

1. acidic urine
2. hypercalcemia, hyperadrenocorticism
3. remove surgically or by urohydropropulsion

Question 15

(ammonium urate uroliths)

1. increase urates in urine (usually from increased dietary intake of purines)
2. more likely in acidic or basic urine?
3. occurs secondary to imparied ability to convert uric acid to what?
4. also associated with what condition?

Answer 15

2. acidic
3. allantoin (dalmations!)
4. PSS

Question 16

(ammonium urate uroliths)

(tx)

1. basic urine, increase water, low protein diet
2. can give what if diet doesn’t work?

Answer 16

2. allopurinol (can cause xanthine uroliths)

Question 17

(calcium phosphate uroliths)

1. caused by acidic or alkaline?
2. what metabolic dz can cause?
3. tx = sx removal

Answer 17

1. alkaline
2. hyperparathyroidism

Question 18

(cystine uroliths)

1. result of a congenital metabolic defect
2. more common in acidic urine (but uncommon)
3. tx = ^ water, basic urine

Question 19

1. what stones occur secondary to allopurinol use?

Answer 19

1. xanthine uroliths

Question 20

(silica uroliths)

1. rare in dogs and cats
2. cause = diet high in corn gluten or soybean hulls
3. tx = sx