Uroliths

Question 1

Struvite is radio____ and occurs in what species? How are struvite stones treated?

Answer 1

Radio-opaque stone common in cats (sterlie) and dogs (secondary to UTI). Also occur in cattle (alkaline urine + high dietary phosphate and magnesium levels).
- Dissolution protocol involves 1) Lower precursors (phosphorus, magneiusm, protein) 2) acidify urine below pH 7 3) increase moisture intake and 4) for dogs, treat UTI

Question 2

Calcium oxalate are radio____ and are most common in ____. How are they treated?

Answer 2

radiodense, most common in cats. May occur in dogs (mini schnazuers, lasa apsos, yorkies) or ruminants. No dissolution protocol; lithotripsy or surgery is necessary.

Question 3

Ammonium urate stones are radio____ and occur most commonly in ______ due to ______. Any dog with a _____ may also form urate stones.

Answer 3

Radiolucent
- Dalmation - reduced conversion of uric acid to allantoin
-Also occur in dogs with portosystemic shunts
- Allopurinol therapy may reduce uric acid production but it requires monitoring as it may predispose dogs to different types of stones (xanthine)
- Soy is high in purines and is not recommended for dogs prone to forming urate stones

Question 4

Cystine

Answer 4

Radio-opaque

• breed predisposition
• renal tubular defect resulting in excess urine cysteine which is poorly soluble
• middle aged dog
• cysteine secretion decreased by castration, dissolution possible but expensive

Question 5

Calcium carbonate stones occur in and require ____ for treatment.

Answer 5

• Most common type in horse and rabbit. Also occur in sheep grazing clover, ruminants on pasture high in calcium and oxalates. Surgical intervention is necessary.

Question 6

Silicate stones occasionally occur in what breed of dogs?

Answer 6

• GSDs predisposed but rare

- seen in sheep and cattle grazing western U.S. rangelands

Question 7

Apatite stones occur in what species?

Answer 7

composed of calcium and phosphate - feedlot cattle

Question 8

Xanthine stones

Answer 8

Allopurinol is used in the treatment of urate stone forming in Dalmations. It acts by inhibiting the enzymes, xanthine oxidase, which metabolizes xanthine. The idea is that by stopping the purine metabolism pathway at this point, uric acid will not be formed in high quantities. However, if given at too high of a dose, xanthine will accumulate to levels where xanthine stones will form.

Question 9

____ stones occur in cattle grazing on mature range grasses along with other factors including dehydration

Answer 9

Silicia

Question 10

The radio-opaque stones are

Answer 10

Calcium oxalate, calcium phosphorus, struvite (usually) and silicia.

Question 11

The most common urolith in cats is _____ whereas in dogs it is ______

Answer 11

Cats - calcium oxalate, Dogs - struvite. Although struvite is common in cats as well.

Question 12

Struvite stones __[can/can’t]___ be dissolved whereas calcium oxolate stones _[can/can’t]____ be dissolved.

Answer 12

Struvite can be dissolved, CaOx cannot

Question 13

Struvite stones in dogs are associated with _____ whereas in cats they are _____.

Answer 13

dogs - struvite associated with UTI. Cats - sterile.

Question 14

____ stones occur commonly in feedlot cattle eating lots of grain

Answer 14

struvite