Louis CaOx Stones Flashcards
small numerous stones in bladder - likely what kind? what should we do?
- Likely Caox but you never know!
- Removal of theses stones is recommended
> can’t dissolve (dispite what food resps say)
should we always perform urolith analysis?
- yes, all uroliths should be submitted (even recurrence)
- quantitative analysis
- results in less than 2 weeks
options for stone removal, from most to least invasive
- cystotomy
- laporoscopic cystotomy
- cystoscopy
- voiding with hydropulsion
CaOx more likely in
adult neutered male dogs
Surgical Removal of stones advantages, disadvantages
Advantages
* Uroliths type diagnosed
* Anatomic abnormality correction
* Urinary bladder sample for culture
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Disadvantages
* Long anesthesia
* Invasive
* Incomplete removal of uroliths (14%)
* Suture induced stone formation
> 9.5% of recurrent stones suture
induced (1999-2006)
> 18.5% in 2018!!!!
> Surgical technique, suture type??
advantages of non0invasive stone removal procedures, and what our options are?
Shorter hospital stay and less pain
* Voiding urohydropropulsion
* Endoscopic
> Basket removal
> Lithotripsy
Voiding Urohydropropulsion
* Indications
* Advantages
Indications
* Stones< urethral diameter
* Female (short and large urethra)
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Advantages
* Minimally invasive
* Easy to perform
* Removal and analysis of stones
Voiding Urohydropropulsion contraindications
Contra-indications
* Large or Jack-shaped stones
* Male cats: risk of obstruction
Intracorporeal Lithotripsy purpose
- how it works?
break up larger stones
* Ho:YAG laser
* Endoscopic guidance under
anesthesia
* Fragmentation of the stones in the bladder and urethra
* Fragments removed by voiding urohydropulsion or basket
Candidates for Lithotripsy
- patients and stones
Patients
* Female dog or cat > 4kg
* Male dogs with urethral stones
Stones
* <2cm in females
* <1cm in males
* Urethral stones easier
* <5 stones for males
Intracorporeal Lithotripsy effectiveness
- Complete fragmentation of stones in all female dogs and 86.7% of male dogs
- Complete urolith removal in 82-84% dogs
- Removal rate higher in females (83-96%) than in males (68- 81%) (Lulich 2009)
- Complete urolith removal in 100% dogs with urethroliths
Post-operative care for Lithotripsy
- Antibiotic (amoxicillin)
- Anti-inflammatory # 5 days
- Micturition monitoring
- Stone analysis
Lithotripsy vs Cystotomy
- how do they compare
- Similar urolith removal and complications
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Lithotripsy - 23 minutes longer (average)
- Discharged 12 hours sooner
Lithotripsy Limitations
- Equip mentcost
- Operator experience
- Size of the patient/scope
- Only for bladder and urethral stones
- Remaining fragments: nidus for new stones?
Percutaneous Cystolithotomy (PCCL)
- when is this technique appropriate?
- how do we approach it? general technique?
- For male dogs (litho not possible)
- For male cats
- Under general anesthesia
- Mini incision (1.5cm) regarding bladder apex * Babcock to grab the bladder wall
- 3 Stay sutures
- Incision of bladder wall + suction
- Port and endoscope
What type of diet should a dog with stones (unknown type) be fed before analysis results?
Maintenance canned diet or Urinary S/O
best method of stone prevention? how can we facilitate this?
Increase Water Consumption
* Use a pet water fountain (continuous filtered fresh running water)
* Provide the pet with fresh water in water dishes in multiple sites
* Add a small amount of flavoring agent to drinking water (tuna juice or low- sodium bouillon)
* Add additional water to dry or wet food
* Offer the dog or cat ice cubes (additional fluid & treat)
* Offer several meals per day
Prevention CAOx
- rule out which pre-disposing factors?
- Cushing
- Obesity
- Hyperparathyroidism
Prevention of Calcium Oxalate Uroliths
- ↑ water consumption
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Potassium citrate - Complexes with calcium (soluble Calcium Citrate)
- Mild urine alkalinization (↑ solubility of CaOx)
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For hypercalcemic cats - Higher fiber content diet
- Vitamin B6
- Hydrochlorothiazide
Diet for Calcium Oxalate Stones Prevention, and goals of this
- Canned diet
- Goal USG:
- <1.020 in dogs
- <1.040 in cats
- Hill’sc/d,PurinaSt/Ox, Royal Canin Urinary S/O
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goal is to increase water consumption, avoid acidifying urine
Diet for Calcium Oxalate Stones Prevention - advice specific to schnauzer?
schnauzer predisposed to pacreatitis
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Becarefulwith Schnauzer (too much fat)
* If hyper lipidemic: Royal Canin Low Fat S/O index (canned)
* If not hyperlipidemic: Royal Canin Urinary S/O Moderate Calorie
* Hill’s w/d
acceptable human foods for dogs prone to stones?
- Vegetables: avocado, cabbage, cauliflower, mushrooms, green peas, radishes, white potatoes
- Fruit: avocado, banana, grapefruit, mangos, melons (cantaloupes, honeydew, watermelon), plums
- Melon increase water intake
Detrimental Human Food for uroliths
- Meats/fish: bologna, herring, oysters, salmon, sardines
- Vegetables: asparagus, baked beans, broccoli, carrots, celery, corn, cucumber, eggplant, green beans, green peppers, lettuce, spinach, sweet potatoes, tofu, tomatoes
- Dairy: cheese, ice cream, milk, yogurt
- Fruits: Apples, apricots, cherries, most berries, limes, lemons, oranges,
pineapple, tangerine - Grains and nuts: corn bread, fruit cake, grits, peanuts, pecans, soybeans, wheat germ
urate stones prevention
- what are common causes we can look for?
- diets?
- what are appropriate treats?
- goal for urine ph?
- Chase the shunt or hepatic dysfunction
- Genetic test
- Low purine diet
> Prescription Diet u/d, RoyalCanin
Low Purine in dogs
> Hill’s prescription diet k/d in cats - Treats: carrots, apple slices, air-popped popcorn
- Urine alkalinization
urate stones prevention
- what to give if crystals persist after diet change?
- how to monitor?
- Monitor urinary tract infection
- If urate crystals persist → Allopurinol
- ↑ Water consumption
- Urine pH, USG, Sediment at 2, 4 weeks and then every 3 months
- Double contrast radiography or Ultrasound every 2 months
- If still uroliths free → every 4 months
cystine stone prevention
- recurrence? why?
- diet goals?
- other
- Risk of recurrence high (inherited defect)
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Diet to provide: - ↑ urine dilution
- Low protein-purine levels
- Alkaline urine
- Limit sodium intake
- Taurine and carnitine supplementation
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- UC Low Purine (Royal Canin)
- +/- 2MPG (thiola) to dissolve cystine
Androgen- dependent type III Cystinuria
- how to prevent? how can we tell the cause?
- If Males of these breeds
- Castration recommended
- If cystinuria ↓ 2 months after castration, ↓ risk of recurrence
- If cystinuria persists after 4 months, not androgen dependent
silicate stone prevention
- avoid ingesting what?
- Avoid ingestion of soil, Soybean hull, rice hull, …
- Avoid pica
- Limit vegetable content of the diet
- ↑ water intake
calcium phosphate stone prevention
- what to target?
Identification and treatment of hypercalcemia
* Primary hyperparathyroidism
* Excess vitamin D
* Systemic acidosis
* Excess dietary calcium or phosphorus
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↑ water consumption
* Canned formula
how to prevent mixed stones,
- Avoid formation of stone type of the nidus (1st to form)
- If Struvite: avoid Infection
- If Calcium oxalate: ↑ water intake
how to prevent suture induced stones
- Avoid surgery
- Suture material that dissolves rapidly (poliglecaprone vs polydioxonone)
Uroliths Recurrence
- rate
- speed for struvite, cystine, calcium oxalate, purine
- Overall 25% recurrence rate
- Struvite within few days
- Cystine within 2-12 months
- Calcium oxalate 42% at 2y
- Purine 33%
when should we recheck for crystals after removal?
- struvute
- cystine
- calcium oxalate
- Struvite within few days
> recheck every 2 weeks
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- Calcium oxalate 42% at 2y
> recheck every 2-4 months for other types of stones
what do we do at a urolith recheck?
USG goal
<1.020 in dogs
<1.045 in cats
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Urinalysis
- pH
- crystals
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Abdominal radiographs
- if small stones, voiding, urohydropulsion
