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Canine and Feline Urolithiasis. Canine and Feline Urolithiasis. Magnesium ammonium phosphate Calcium oxalate Urate Cystine Calcium phosphate Silicate Mixed stones. Canine Urolithiasis Prevalence (%). 1986 1990 1994 Struvite 67.0 57.0 49.5
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Canine and Feline Urolithiasis • Magnesium ammonium phosphate • Calcium oxalate • Urate • Cystine • Calcium phosphate • Silicate • Mixed stones
Canine UrolithiasisPrevalence (%) 1986 1990 1994 • Struvite 67.0 57.0 49.5 • Calcium oxalate 6.8 19.8 32.7 • Urate 5.1 5.5 8.0 • Cystine 2.4 1.6 1.0 • Calcium phosphate 3.0 1.6 0.6 • Mixed/Compound 11.9 12.6 7.4
Feline UrolithiasisPrevalence (%) 1986 1990 1996 • Struvite 85.0 66.0 36.4 • Calcium oxalate 3.0 16.0 53.4 • Urate 1.8 6.1 4.9 • Cystine 0.0 0.1 0.1 • Calcium phosphate 2.0 2.9 0.6 • Mixed/compound 5.2 5.9 3.4
Canine and Feline UrolithiasisPathogenesis • Concentration of building blocks • Urinary pH • Time
labile region critical supersaturation increasing activity product metastabile supersaturation saturation, Ksp undersaturation Canine and Feline UrolithiasisPathogenesis
Canine and Feline UrolithiasisPathogenesis Activity Product • Concentration of crystal constituents • Concentration of other solutes • Urine pH • Ionic strength
Feline Lower Urinary Tract DiseasePathogenesis • Uroliths • Urethral plugs • Large quantity of matrix ( > 50% matrix) • Mixed with crystals or without crystals
Canine and Feline UrolithiasisClinical Diagnosis • Age • Gender • Breed • Radiograhic findings • Crystalluria • Urinary pH • Presence of infection
Canine and Feline UrolithiasisClinical Diagnosis • Urinary pH • Alkaline Struvite Calcium apatite • Acid to neutral Calcium oxalate Cystine
Canine and Feline UrolithiasisClinical Diagnosis • Presence of Infection Urease producing micro-organisms Struvite • Dogs most cases UTI • Cats 1-2% UTI
2NH3+ CO2 NH2 =C=NH2 + H2O = O Urease NH3+ H2O + CO2 NH4++ HCO3- Canine UrolithiasisUrease producing bacteria
Canine and Feline UrolithiasisTreatment & Prevention • Treatment Dietary & Medical dissolution Surgical Non-surgical retrieval • Prevention of recurrence Dietary modifications Water intake
Canine and Feline UrolithiasisDietary management • Undersaturate the urine Excretion of building blocks Urine volume • Urinary pH favorable to stone dissolution
Feline Lower Urinary Tract DiseaseStruvite & calcium oxalate • No single diet for both struvite and calcium oxalate • Conflicting actions of several key nutrients • Clinical diagnosis is essential
pH Mg PO4 Na Canine and Feline Urolithiasis Lower Urinary Tract Disease Struvite Ca Oxalate
Feline Lower Urinary Tract DiseaseStruvite Patient profile • Female • Younger cat, < 7 years • Obese • Indoor, multi-cat household • Low water intake • More alkaline urinary pH (> 6.5)
Feline Lower Urinary Tract DiseaseCalcium oxalate Patient profile • Male (neutered) • Older cat > 4 years • Obese • Persian, Himalayan, Burmese • Indoor, urban • More acid urinary pH
Feline Lower Urinary Tract DiseaseCalcium oxalate Medical history • History of calcium oxalate, documented by quantitative urolith analysis • No response to appropriate dietary struvite therapy • Inappropriate use of urinary acidifiers
Feline Lower Urinary Tract DiseaseCalcium oxalate • Treatment Surgery • Prevention Avoid dietary and medical risk factors
Feline Lower Urinary Tract DiseaseCalcium oxalate Dietary risk factors • Excess vitamin C & D • Acidification • Ad libitum feeding • Moderate protein = protective • Very low protein = risk factor • Low fiber • Feeding dry • Excessive Ca & P restriction
Feline Lower Urinary Tract DiseaseCalcium oxalate Nutrient profile • Potassium citrate • Urinary pH 6.6-6.8 • Increased moisture • Pyridoxine (vitamin B6) • Soluble fiber • Moderate magnesium
Feline Lower Urinary Tract DiseaseStruvite Mg - NH4 - PO4 . 6H20 • Magnesium • Ammonium • Anionic phosphate
Feline Lower Urinary Tract DiseaseStruvite Dietary management • Reduced magnesium Less than 20 mg/100 kcal ME Less than 0.1% (dry matter) • Increased diuresis Water Sodium
Feline Lower Urinary Tract DiseaseStruvite Dietary management • Acid urine pH • Avoid over-acidification Metabolic acidosis Renal disease • Dissolution - urinary pH 5.9 - 6.1 • Prevention - normal acid urinary pH 6.2-6.4
Canine and Feline UrolithiasisUrinary acidification • Decrease in urine pH from 8.5 to 5.5 • NH4+ - 1000 x Increase • PO4 3- - 13 000 x decrease • Moderately acid urine • pH : 6.2 - 6.4
Contra-indicaties voor verzurend dieet • Nierinsufficiëntie • Groei (ontkalking) • Acidose • Ca-oxalaat stenen • Urineverzuurders toevoegen aan verzurend dieet
Feline Lower Urinary Tract DiseaseStruvite Dietary management • Feed calculolytic diet exclusively • 1 - 2 months • Longer if UTI is present • If no reduction of calculi after 2 months, surgery should be considered
Canine UrolithiasisStruvite Mg - NH4 - PO4 . 6H20 CrystalDiet • Magnesium Magnesium • Ammonium Protein • Anionic phosphate Phosphorus
Canine UrolithiasisStruvite - Dissolution Nutrients • Minimize protein • Reduce magnesium • Reduce phosphorus • Stimulate water intake • Increase sodium Acidify urine
Canine UrolithiasisStruvite - Dissolution % DM Normal Calculolytic FoodsDiet • Protein 15 - 60 7.6 • Magnesium 0.03 - 0.27 0.02 • Phosphorus 0.41 - 2.43 0.10 • Sodium 0.11 - 2.22 1.28 • Urinary pH 6.7 - 8.3 5.9 - 6.1
Canine UrolithiasisStruvite - Dissolution • Feed calculolytic diet exclusively • Treat urinary tract infection • Continue treatment till 4 weeks after radiographic dissolution
Canine UrolithiasisStruvite - Dissolution Monthly evaluation • Radiography • Serum urea nitrogen (SUN) • Urinalysis: crystals, culture bacteria Owner compliance • Struvite crystalluria • SUN > 10 mg/dl
Canine UrolithiasisStruvite - Dissolution Reasons for failure • Insufficient time • Non-compliance by owner • Urinary tract infection • Non-Struvite urolith
Canine UrolithiasisStruvite - Treatment Indications for surgery • Obstruction • Anatomical defects • No response to medical treatment • Diet is contraindicated
Canine UrolithiasisStruvite - Treatment Diet contra-indications • Sodium retention Heart failure, hypertension, liver disease, nephrotic syndrome • Increased protein requirements Pregnancy, lactation, growth, cats • Acidifing diet Renal insuff., metabolic acidosis, growth, Ca-ox.
Canine UrolithiasisStruvite - Prevention Prevention of recurrence • Urinary acidification • Moderate reduction of protein, Mg, P • Moderate sodium level
Canine UrolithiasisCalcium oxalate Treatment • Surgery • Hydropropulsion
Canine UrolithiasisCalcium oxalate Verminderen uitscheiding bouwstenen • Calcium Ca-opname + Calciurie Vitamine D3: Ca aborptie + indirect calciurie P: te laag: stimulatie Vit D3 Na: stimulatie calciurie Zure urine: stimulatie calciurie • Oxalaat: spinazie, rubarber, chocolade
Canine UrolithiasisCalcium oxalate Verhogen inhibitoren • Magnesium • pH urine: Alkalinserend: vb. K-citraat Dierlijke eiwitten verzuren: hoge eiwitopname vermijden Andere: wateropname
Canine UrolithiasisCalcium oxalate - Prevention Prevention of recurrence • Avoid excessive intake of protein • Low calcium intake • Low oxalate intake • Low sodium intake • Avoid urinary acidification • Potassium citrate
Canine UrolithiasisCalcium oxalate Prevention of recurrence • Advanced renal failure diet
Canine UrolithiasisAmmonium urate - Treatment Dissolution • Dietary management • Allopurinol • Urinary tract infection
Meat diets Canine UrolithiasisAmmonium urate - Treatment Allopurinol Xanthine + Xanthine oxidase Purine / Pyrimidine (Nucleic acids & Cell nuclei) Uric acid + Uricase (Defect in Dalmatians) Allantoin
Canine UrolithiasisAmmonium urate - Treatment Dietary management • Ammonium - Low protein • Urate - Low purine Muscle & organ tissue = high in purines Egg & casein = low in purines • Alkalinize urine
H+ NH4+ NH3 Canine UrolithiasisAlkalinize urine Decreases NH4+ concentration
Canine UrolithiasisAmmonium urate - Treatment • Advanced renal failure diet • 8 - 11 weeks required for dissolution • Monitor for urethral obstruction
Canine UrolithiasisAmmonium urate - Prevention Prevention of recurrence • Advanced renal failure diet Low in protein & purines Alkalinizing the urine • Allopurinol
Canine UrolithiasisCystine - Composition = Cysteïne - Cysteïne Genetische afwijking: gestoorde reabsorptie van Cystine: weinig oplosbaar Ornithine Lysine wateroplosbaar Alanine
Canine UrolithiasisCystine - Treatment Surgery Dissolution