Urolithiasis

Question 1

signs of LUT uroliths

Answer 1

pollakiuria, stranguria, hematuria

Question 2

signs of UUT uroliths

Answer 2

anorexia, malaise, sub lumbar pain, uremia, hematuria

Question 3

relative supersaturation (RSS)

Answer 3

measures the risk of crystals forming in the urine; ratio of activity product to solubility constant

Question 4

undersaturation

Answer 4

no crystallization
crystal dissolution

desired for urinary stone diets, urine state, etc for stone prevention and treatment

Question 5

metastable supersaturation

Answer 5

no spontaneous crystallization
no crystal dissolution possible

Question 6

labile supersaturation

Answer 6

spontaneous crystallization
crystal growth/aggregation

Question 7

crystalluria

Answer 7

crystals in the urine

Question 8

is crystalluria always a disease state

Answer 8

NO - can have crystals in health

Question 9

what is a stone matrix

Answer 9

the material that gets incorporated into the stone lattice as it forms (protein, cell debris, foreign bodies, drug residues, etc)

Question 10

if concurrent stones + crystalluria, is the stone type always the same as the crystal type

Answer 10

NO - can be, but not always

Question 11

what stone types occur from genetic mutations in dogs

Answer 11

urate and cystine

Question 12

what is the best diagnostic for stones

Answer 12

radiographs (for radio-dense stones)

ultrasound or cystourethrogram (for radio-lucent stones)

Question 13

what stones are radio-dense

Answer 13

struvite
Ca oxalate or phosphate

Question 14

what stones are radio-lucent

Answer 14

urate (purine) and cystine

Question 15

what are other diagnostic options for stones

Answer 15

contrast studies (positive or double contrast), excretory urography, cystoscopy

Question 16

what diagnostic is best for measuring stone size

Answer 16

radiographs

ultrasound OVERESTIMATES size (best option for radiolucent)

Question 17

what are some methods of stone removal

Answer 17

cystotomy
dissolution
voiding urohydropropulsion
laser and basket retrieval

Question 18

cystotomy

Answer 18

surgical removal of the stones

most common for all types

Question 19

dissolution

Answer 19

dissolving the stones

only used for struvite and some urate/cystine stones

can NOT dissolve Ca stones

Question 20

voiding urohydropropulsion

Answer 20

infusing the bladder until full, positioning the patient upright, shake and remove catheter while expressing the bladder to void stones

repeat until empty

Question 21

laser and basket retrieval

Answer 21

laser the stone until it gets broken up; retrieve the largest piece with a basket then use VUH to empty remaining pieces

Question 22

primary uroliths in dogs

Answer 22

Ca oxalate
struvite
urate
Ca phosphate
cystine
silica

Question 23

primary uroliths in cats

Answer 23

struvite
Ca oxalate
urate
dried blood
Ca phosphate

Question 24

where is the main site of Ca oxalate stones

Answer 24

dogs: bladder
cats: ureters

Question 25

what pH do CaOx dihydrate stones form in

Answer 25

acidic

Question 26

what is the signalment for CaOx stones

Answer 26

middle aged males some breed dispositions

Question 27

what is the best prevention for CaOx stones

Answer 27

serum Ca monitoring high water intake

Question 28

where is the main site of struvite stones

Answer 28

lower urinary tract (can be upper in dogs)

Question 29

what is the main cause of struvite stones in dogs

Answer 29

urease producing bacteria always culture urine if struvite stones identified in dogs

Question 30

what pH do struvite stones form in

Answer 30

alkaline

Question 31

how do you treat struvite stones

Answer 31

cats: acidic diet dogs: acidic diet + antibiotics

Question 32

can you prevent struvite stones in dogs

Answer 32

NO - need to prevent the UTI of urease producing bacteria in order to prevent struvite stones

Question 33

what enzyme converts hypoxanthine to xanthine in protein metabolism

Answer 33

xanthine oxidase

Question 34

what enzyme converts xanthine into uric acid in protein metabolism

Answer 34

xanthine oxidase

Question 35

where does uric acid travel to continue protein metabolism

Answer 35

the liver

Question 36

what enzyme converts uric acid to allantoin in protein metabolism

Answer 36

uricase

Question 37

what are the two ways of obtaining urate uroliths

Answer 37

1. hyperuricosuria mutation 2. portosystemic shunts

Question 38

hyperuricosuria mutation

Answer 38

defective transporters prevent uric acid from entering hepatocytes, preventing conversion of uric acid to allantoin --> uric acid accumulates in circulation --> kidneys can't reabsorb --> accumulates in urine --> forms urate stones common in Dalmatians

Question 39

how do portosystemic shunts cause urate stones

Answer 39

PSS causes blood to bypass the liver --> uric acid can't reach hepatocytes --> unable to convert to allantoin --> uric acid accumulates --> forms urate stones resolving PSS will resolve the urate stones

Question 40

what stones are most common in goats

Answer 40

Ca carbonate (alfalfa) struvite (grain)

Question 41

what stones are most common in cows

Answer 41

struvite (grain) silica (soil)

Question 42

what stones are most common in horses

Answer 42

Ca carbonate caused by alkaline urine

Question 43

what stones are most common in chelonians

Answer 43

urate caused by uric acid as final waste product

Question 44

what stones are most common in rodents

Answer 44

Ca carbonate

Question 45

what stones are most common in pigs

Answer 45

amorphous magnesium calcium phosphate (AMCP)