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Question 1

What is urolithiasis?

Answer 1

Urolithiasis is a disease characterized by the formation of uroliths, or urinary stones.

Question 2

What are the causes of urolithiasis in domestic animals?

Answer 2

The formation of urinary stones can be a consequence of chronic inflammation of the urinary tract.

Question 3

What are uroliths composed of?

Answer 3

Uroliths are composed of an organic matrix and crystalline minerals of various compositions. The matrix constitutes a smaller portion of 2-10%.

Question 4

How are uroliths classified based on localization?

Answer 4

Uroliths can be classified as nephrolith (in kidneys), ureterolith (in ureters), urocystolith (in bladder), and uretrolith (in urethra).

Question 5

How are uroliths classified based on mineral composition?

Answer 5

Uroliths can be classified as monomineral (over 70% of one dominant mineral), complex (core and shell), or mixed (not exceeding 70% of any mineral, without core and shell).

Question 6

What are the shapes of uroliths?

Answer 6

Uroliths can be round, oval, pyramidal, spiny, or bizarre.

Question 7

What are the causes of urolith formation?

Answer 7

Uroliths can form due to infectious causes (struvite) or metabolic causes (cystine, urate, oxalate, silicate).

Question 8

What factors predispose animals to urolithiasis?

Answer 8

Factors include breed predisposition, age, sex, nutrition, genetic factors, pathological morphology of kidneys, urinary tract infections, metabolic defects, and urodynamic disorders.

Question 9

Which breeds are predisposed to struvite uroliths?

Answer 9

Breeds include Miniature Schnauzer, Bichon Frise, and Cocker Spaniel.

Question 10

Which breeds are predisposed to calcium oxalate uroliths?

Answer 10

Breeds include Miniature Schnauzer, Lhasa Apso, Yorkshire Terrier, Toy Poodle, Shih Tzu, and Bichon Frise.

Question 11

Which breeds are predisposed to urate uroliths?

Answer 11

Breeds include Dalmatian, English Bulldog, Miniature Schnauzer, and Yorkshire Terrier.

Question 12

Which breeds are predisposed to cystine uroliths?

Answer 12

Breeds include English Bulldog, Dachshund, and Basset Hound.

Question 13

How is urolithiasis diagnosed?

Answer 13

Urolithiasis must be differentiated from infections and tumors. Urine analysis and possibly ultrasound examination are required.

Question 14

What does urine analysis reveal in urolithiasis?

Answer 14

Urine analysis checks pH, presence of bacteria, and crystals, which helps identify the composition of urinary stones.

Question 15

What is struvite urolithiasis in dogs?

Answer 15

Struvite urolithiasis is associated with infection and is characterized by colorless crystals shaped like coffin lids or X shapes.

Question 16

What bacteria are associated with struvite urolithiasis?

Answer 16

Bacteria such as Proteus mirabilis, Proteus vulgaris, Staphylococcus aureus, and Ureaplasma urealyticum are associated with struvite formation.

Question 17

What pH level indicates struvite crystals in urine?

Answer 17

Struvite crystals in urine indicate a pathologically high pH (above 7.2).

Question 18

What are the main factors for struvite formation?

Answer 18

The main factors include increased concentration of ammonium ions (high protein diet) and alkaline pH.

Question 19

What dietary factors contribute to struvite urolithiasis?

Answer 19

Dietary factors include high protein intake leading to increased urea and alkaline urine.

Question 20

What is calcium oxalate urolithiasis?

Answer 20

Calcium oxalate urolithiasis involves the formation of dipyramidal crystals, which can be colorless or vary in color.

Question 21

What conditions lead to calcium oxalate urolithiasis?

Answer 21

Conditions include hypercalciuria (excess calcium) and hyperoxaluria (excess oxalate).

Question 22

What are the treatment options for calcium oxalate uroliths?

Answer 22

Treatment includes surgical removal of uroliths, urine acidification, and dietary management.

Question 23

What is cystine urolithiasis?

Answer 23

Cystine urolithiasis involves colorless crystals with a hexagonal shape, often forming in concentrated urine with acidic pH.

Question 24

What is the etiology of cystine urolithiasis?

Answer 24

Cystinuria is an autosomal recessive condition leading to cystine urolith formation.

Question 25

What are the characteristics of cystine crystals?

Answer 25

Cystine crystals have equal or nearly equal sides and can occur individually, but more often aggregate into layers.

Question 26

In what conditions do cystine crystals most commonly form?

Answer 26

They most commonly form in concentrated urine with acidic pH.

Question 27

What is cystinuria?

Answer 27

Cystinuria is an autosomal recessive inherited metabolic disorder (tubulopathy) caused by a defective gene leading to increased cystine excretion in urine.

Question 28

Which dog breeds are commonly affected by cystinuria and cystine urolith formation?

Answer 28

Affected breeds include: Basenjis, Basset Hounds, Bulldogs, Shih Tzus, Yorkshire Terriers, Irish Terriers, Newfoundland Dogs, Mastiffs, and their crosses.

Question 29

What happens to cysteine in the proximal tubule in cystinuria?

Answer 29

Cysteine is not completely reabsorbed, leading to its presence in the final urine where it converts to cystine, which is poorly soluble in water.

Question 30

What is the color of cystine crystals?

Answer 30

Cystine crystals are yellow, brown, or greenish and usually occur in several pieces.

Question 31

What is purine urolithiasis?

Answer 31

Purine urolithiasis refers to the presence of uroliths formed from animal proteins.

Question 32

What are the two groups of patients affected by urate lithiasis in dogs?

Answer 32

The two groups are: Dalmatian dogs and non-Dalmatian breeds.

Question 33

What is the primary cause of urate stone formation in Dalmatians?

Answer 33

Dalmatians have a unique metabolic defect that limits their ability to oxidize uric acid to allantoin.

Question 34

How much uric acid is converted to allantoin in Dalmatians compared to other breeds?

Answer 34

Only 30-40% of uric acid is converted to allantoin in Dalmatians, compared to 90% in other breeds.

Question 35

What is the uric acid excretion level in Dalmatians?

Answer 35

Dalmatians excrete 400-600 mg of uric acid in 24 hours, while similar-sized breeds excrete approximately 60 mg.

Question 36

What is the role of renal tubules in uric acid handling in Dalmatians?

Answer 36

Dalmatian renal tubules reabsorb less uric acid than other breeds and also secrete uric acid in their distal renal tubules.

Question 37

Is increased urate excretion in Dalmatians a primary cause of urate lithiasis?

Answer 37

Increased urate excretion is a risk factor, not the primary cause, as all Dalmatians have the metabolic defect but only some develop urolithiasis.

Question 38

What other types of stones can occur in Dalmatians?

Answer 38

About 10% of cases may involve struvite, calcium oxalate, cystine, or other types.

Question 39

What factors contribute to urate lithiasis in non-Dalmatian breeds?

Answer 39

Factors include hyperuricosuria, hyperammonuria, and low urine pH.

Question 40

What liver dysfunctions are associated with urate lithiasis in dogs?

Answer 40

Liver dysfunctions can lead to increased ammonia levels, often due to portosystemic shunts or cirrhosis.

Question 41

What is the metabolic origin of urate?

Answer 41

Urate is produced during the metabolism of purines and pyrimidines found in nucleic acids.