Urinary3- Urolithiasis

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  1. The _______ is USG, the more likely crystals are to form; the _______ the temperature of the urine, the _________ the conc of inhibitor substances, and the _________ the excretion of inhibitor substances, the more likely crystals are to form.
    higher; lower; lower; higher
  2. The urine pH DOES NOT AFFECT the solubility of ____________.
    calcium oxalate crystals
  3. There is a higher risk of stone formation when urine is ___________.
    highly saturated
  4. __(2)__ should warrant further evaluation in dogs.
    Cystine and urate
  5. When are crystals a problem? (5)
    in a patient who is a known stone-former, patient with LUT signs, male cat with history of plug formation/obstruction, persistent/significant crystalluria, urate or cystine crystals
  6. What are predisposing factors to stone development? (4)
    infection, tubular defects, metabolic defects, crystalluria
  7. How does infection lead to struvite crystalliuria?
    infection with urease-utilizing bacteria--> makes urine more alkaline--> struvite precipitates out in alkaline urine
  8. What kind of crystals are found with tubular defects? (2)
    cystine, calcium oxalate
  9. What kind of crystals are associated with some metabolic defects? (2)
    urate, calcium oxalate
  10. Clinical signs of patients with stones. (7)
    hematuria, pollakiuria, obstruction/stranguria, post-renal azotemia, abdominal pain, painful urination, recurrent UTIs
  11. Describe common PE findings with urolithiasis. (4)
    painful abdomen, abnormal urethral/bladder palpation, hematuria on fur
  12. What are some CBC findings associated with urolithiasis? (1)
    +/- stress leukogram
  13. What are serum chem findings that may be associated with stones? (2)
    azotemia, +/- hepatic dysfunction with urate crystals
  14. UA findings with urolithiasis. (3)
    +/- hematuria, +/- pyuria, +/- crystalluria
  15. What are the most radiopaque stones to the least (in order)?
    struvite--> calcium oxalate--> cystine--> urate
  16. How do you definitively diagnose urolithiasis? (2)
    radiographs, US can see stones that are too small or radiolucent to see on rads
  17. How do you definitively determine what type of stone is present?
    quantitiative analysis of the stone after it is removed
  18. In cats, struvite stones usually occur in a(n) __________ environment.
  19. How do you treat struvite stones in a cat?
    medically dissolve with Hill's c/d or s/d and NO OTHER TREATS, monitor for decrease in size and keep urine pH low and keep urine dilute
  20. What dietary measures may contribute to the formation of struvite stones in cats? (2)
    high Mg and high Ph
  21. Keeping urine acidic helps prevent _________ stones, but may cause precipitation of __________.
    struvite; calcium oxalate stones
  22. Struvite stones in dogs are usually associated with ______________.
    UTI from Staph spp. and Proteus
  23. How do you treat struvite stones in dogs? (3)
    medical dissolution with Hill's s/d diet, TREAT UTI, monitor for low urine pH, low USG, and urine culture
  24. Calcium oxalate stones occur when...
    urine is oversaturated with calcium and oxalate.
  25. What inhibits formation of calcium oxalate stone in normal urine? (3)
    nephrocalcin, uropontin, and Tamm-Horsfall proteins
  26. ___________ can predispose tohypercalciuria.
  27. __________ can predispose to hypercalciuria because the more calcium is excreted under these conditions and inhibitors are negatively affected.
    metabolic acidosis
  28. Calcium oxalate stones are lowest in cats on _________ diets and highest in cats on _________ diets.
    alkalinizing; acidifying
  29. What should you not give in excess to ats with calcium oxalate stones? Why?
    Vit C because oxalic acid is an end product of its metabolism
  30. _________ deficiency can increase urinary oxalate levels.
    Vit B6
  31. What is the most common stone in cats?
    calcium oxalate
  32. How do you treat calcium oxalate stones in cats? (3)
    surgery to remove (cannot dissolve medically), increase water intake, alkalinize urine
  33. How do you treat calcium oxalate stones in dogs? (5)
    surgery to remove (cannot dissolve), increase water intake, high rate of recurrence/continue monitoring, keep urine neutral, special diets
  34. What kind of urate stones do felines get?
    ammonium acid urate (may be part of compound stones) [fairly rare in cats]
  35. In cats, urate stones are sometimes associated with ___________.
    hepatic dysfunction
  36. In dogs, urate stones are always associated with... (2)
    hepatic dysfunction (portosystemic shunts) or inborn error of ammonium metabolism.
  37. How do you treat urate stones in cats? (4)
    surgical removal, increase water intake, low protein diet (reduce amount of ammonia), Allopurinol (blocks formation)
  38. In dogs, urate crystals precipitate in __________ urine.
    neutral to acidic
  39. What dog breeds most commonly get urate crystals? (3)
    Dalmations, English Bulldogs, Yorkshire Terriers
  40. How do portosystemic shunts lead to urate stones?
    increased ammonia and uric acid in urine because it is not cleared by the liver
  41. What disorder do all Dalmatians genetically have?
    disorder of transport of urate into hepatocytes where urate oxidase lives, leading to hyperuricosuria/uricosemia (linked to spot color/size)
  42. What MUST you rule out in dogs with urate crystals? How do you rule it out?
    portosystemic shunt- bile acids, imaging
  43. How do you treat dogs with urate stones? (4)
    medical dissolution with Hill's u/d (low protein diet), monitor for low BUN, treat PSS if present, Allopurinol
  44. How does Allopurinol work?
    xanthine oxidase inhibitor- prevents metabolism of xanthine to uric acid (can lead to xanthine stones if not on a low protein diet concurrently)
  45. What causes cystine stones?
    defect in renal tubular transport of cystine, orinthine, lysine, and arginine (COLA transporter), causing it to be dumping into the urine, where cystine precipitates
  46. If there is cystine crystals in the urine, you know there is a defect in the ____________.
    proximal tubule
  47. How do you treat cystine stones in cats? (2)
    surgical removal, increase urine pH (increase dietary potassium citrate), 2-MPG (Thiola)
  48. Cystine precipitates out in _________ urine.
  49. What are the 3 types of cystine transport mutations in dogs?
    • Type I- autosomal recessive- Newfies, Labs, Landseer
    • Type II- autosomal dominant- Au Cattle dog, MinPin
    • Type III- sex-linked, androgen dependent, intact males- mastiff, deerhound, irish terrier
  50. How do you treat type I and type II cystine stones in dogs? (5)
    dissolution with Hill's u/d OR surgical removal, increase urine pH (potassium citrate), 2-MPG (Thiola- converts cystine to more soluble compound), monitor for relapse
  51. How do you treat type III cystine stones in dogs? (2)
    surgical removal, NEUTER THE DOG
  52. How do you treat silicate stones in dogs?
    surgical removal
  53. Silicate stones precipitate in __________ urine.
    neutral to acidic
  54. Calcium phosphate stones precipitate in ___________.
    alkaline urine
  55. How do you treat calcium phosphate stones in dogs? (2)
    treat underlying metabolic disorder and keep urine pH neutral
  56. Describe prevention and monitoring of bladder stones. (4)
    keep urine dilute (USG < 1.030), special diets, periodic radiographs, voiding urohydropulsion  as needed (flush them out of the bladder before they get too big and require surgery)
  57. What is an important factor for treating any dog with stones (not required with cats)?
    keep them on antibiotics until a week after the stones are radiographically dissolved
  58. What is the most common type of nephro- and ureteroliths?
    calcium oxalates (esp. in cats)
  59. Under what circumstances do you remove renoliths in SA? (3)
    recurrent UTI, evidence of obstruction (dilated renal pelvis, hydronephrosis), evidence of pain
  60. What is the main type of stone in ureteroliths?
    calcium oxalate stones (cats!)
  61. What happens within 4 weeks of ureterolith obstruction?
    permanent renal impairment in the kidney
  62. How do you diagnose reno- and ureteroliths? (2)
    imaging (rads- BKLK (big kidney little kidney), US), CBC/Chem
  63. Describe medical management of reno- and ureteroliths. (3)
    diuresis, ureteral relaxation (Prazosin, Tamulosin), pain control
  64. What are requirements for medical management of reno- or ureteroliths? (4)
    stone in distal 1/3 of ureter, adequate urine output, normal to moderate azotemia, improvement in 48-72 hours---> THEN REFER
  65. What are the 3 general theories of urolith formation?
    • Precipitation- Crystallization theory (urine supersaturated with crystalloids)
    • Matrix- Nucleation theory (abnormal substance in the urine)
    • Crystallization- Inhibition Theory (absence of a critical inhibitor or presence of a promoter)
  66. Most common type of stone in:
    • Dogs- Struvite
    • Cats- Calcium oxalate
    • Horses- Calcium carbonate
  67. Why are females dogs more likely than males to get struvite stones? Why are males more likely than females to get other types of stones?
    • Struvite- females are more likely to have a UTI b/c of their short urethra
    • Other stones- males have a longer urethra and os penis, making it less likely for them to be able to urinate out small stones, allowing them to get bigger and cause obstruction
  68. Factors involved in the pathogenesis of oxalate urolithiasis. (5)
    increased urinary excretion of calcium, exclusively acidifying diets, decreased urinary citrate (normals binds Ca2+ to prevent stone formation), increased dietary oxalate, Ca2+, Vit C (oxalic acid is end product), decreased dietary Vit B6
  69. Why are cats more likely to be affected by oxalate urolithiasis?
    over-acidifying diets lead to more calcium and oxalate in the urine
  70. What physiologic factors predispose horses to calcium carbonate urolithiasis? (3)
    normally high urinary calcium excretion, alkaline urine, large amount of mucus in urine
  71. What are the clinical signs associated with urolithiasis determined by? (4)
    anatomic location of calculi, duration of presence, physical features of calculi, presence or absence of UTI
  72. What clinical signs would you expect to see in a dog with cystic calculi?
    none unless concurrent UTI (in which case you would see dysuria, increase in frequency of urination, hematuria)
  73. What clinical signs would you expect to see in a steer with urethral calculi? (3)
    frequent unsuccessful attempts to urinate, small amounts of urine/dribbling urine, abdominal pain (kicking belly, switching tail)
  74. How can you relieve urethral calculi obstruction in dogs? (2)
    well-lubricated, small diameter urinary catheter, retrograde urohydropulsion
  75. In what situations is supplemental salt advised? (2)
    cattle to prevent silicate stones, MAYBE with struvite urolithiasis b/c salt induces diuresis and dilution of urine
  76. In what circumstances is supplemental salt not recommended? (1)
    urate urolithiasis- low protein, low purine diet already promotes diuresis and low USG, increased sodium may promote calciuresis
  77. In what circumstances should you absolutely not give supplemental salt? (1)
    oxalate stones- natiuresis is associated with hypercalciuria
  78. Which stones are treated/managed with Prescription Diet S/d? Why?
    struvite stones- low Ph, Mg2+, and protein; high salt--> promotes undersaturation with ions needed for struvite formation, salt promotes diuresis
  79. What stones are managed with Prescription Diet U/d? Why?
    Urate calculi, maybe cystine- low protein, low purine, potassium citrate is alkalinizing agent--> decreased urinary excretion of uric acid, ammonia, and acid; decreased medullary urea content--> increased urine output --> increased urine output and low USG
  80. How does D-penicillamine work in treating cystine urolithiasis?
    forms a disulfide bond with cysteine, making it 50x more soluble and reducing the cystine content in the urine
  81. How does 2-MPG work in treating cystine urolithiasis?
    thiol disulfide exchange reaction, making cystine more soluble
  82. What is the rationale for alkalinizing urine of animals with cystine urolithiasis?
    cystine has high solubility in urine pH >7.8
  83. What is the rationale for alkalinizing urine of animals with urate urolithiasis? (2)
    increased pH decreases urinary ammonium ion concentration (which contribute to ammonium urate crystal formation), uric acid is more soluble in alkaline urine
  84. Why might you choose potassium citrate over sodium bicarb as an alkalinizing agent?
    natriuresis enhances calciuresis AND urinary cystine excretion (ie. bad for cystine AND urate urolithiasis)
  85. How can you prevent urate stones? (2)
    Prescription Diet U/d +/- allopurinol
  86. How can you prevent Cystine stones? (1)
    Prescription Diet U/d
  87. How can you prevent oxalate stones? (4)
    low calcium and oxalate diet, avoid Vit C, +/- supplement citrate [Prescription Diets U/d, K/d, and W/d]
Card Set:
Urinary3- Urolithiasis
2015-12-07 01:48:58
vetmed urinary3

vetmed urinary3
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