Canine and Feline Urolithiasis Canine and Feline Urolithiasis

Canine and Feline Urolithiasis

Canine and Feline Urolithiasis ü Magnesium ammonium phosphate ü Calcium oxalate ü Urate ü Cystine ü Calcium phosphate ü Silicate ü Mixed stones

Canine Urolithiasis Prevalence (%) ü Struvite ü Calcium oxalate ü Urate ü Cystine ü Calcium phosphate ü Mixed/Compound 1986 67. 0 6. 8 5. 1 2. 4 3. 0 11. 9 1990 57. 0 19. 8 5. 5 1. 6 12. 6 1994 49. 5 32. 7 8. 0 1. 0 0. 6 7. 4

Feline Urolithiasis Prevalence (%) ü Struvite ü Calcium oxalate ü Urate ü Cystine ü Calcium phosphate ü Mixed/compound 1986 85. 0 3. 0 1. 8 0. 0 2. 0 5. 2 1990 66. 0 16. 0 6. 1 0. 1 2. 9 5. 9 1996 36. 4 53. 4 4. 9 0. 1 0. 6 3. 4

Canine and Feline Urolithiasis Pathogenesis üConcentration of building blocks üUrinary p. H üTime

Canine and Feline Urolithiasis Pathogenesis labile region critical supersaturation metastabile supersaturation, Ksp undersaturation increasing activity product

Canine and Feline Urolithiasis Pathogenesis Activity Product üConcentration of crystal constituents üConcentration of other solutes üUrine p. H üIonic strength

Feline Lower Urinary Tract Disease Pathogenesis üUroliths üUrethral plugs 3 Large quantity of matrix ( > 50% matrix) 3 Mixed with crystals or without crystals

Canine and Feline Urolithiasis Clinical Diagnosis üAge üGender üBreed üRadiograhic findings üCrystalluria üUrinary p. H üPresence of infection

Canine and Feline Urolithiasis Clinical Diagnosis ü Urinary p. H 3 Alkaline Struvite Calcium apatite 3 Acid to neutral Calcium oxalate Cystine

Canine and Feline Urolithiasis Clinical Diagnosis üPresence of Infection Urease producing micro-organisms Struvite 3 Dogs most cases UTI 3 Cats 1 -2% UTI

Canine Urolithiasis Urease producing bacteria NH 2 =C=NH 2 + H 2 O = 2 NH 3 + CO 2 O NH 3 + H 2 O + CO 2 Urease NH 4 + HCO 3 +

Canine and Feline Urolithiasis Treatment & Prevention üTreatment Dietary & Medical dissolution Surgical Non-surgical retrieval üPrevention of recurrence Dietary modifications Water intake

Canine and Feline Urolithiasis Dietary management üUndersaturate the urine Excretion of building blocks Urine volume üUrinary p. H favorable to stone dissolution

Feline Lower Urinary Tract Disease Struvite & calcium oxalate ü No single diet for both struvite and calcium oxalate ü Conflicting actions of several key nutrients ü Clinical diagnosis is essential

Canine and Feline Urolithiasis p. H Mg PO 4 Na Lower Urinary Tract Disease Struvite Ca Oxalate

Feline Lower Urinary Tract Disease Struvite Patient profile ü Female ü Younger cat, < 7 years ü Obese ü Indoor, multi-cat household ü Low water intake ü More alkaline urinary p. H (> 6. 5)

Feline Lower Urinary Tract Disease Calcium oxalate Patient profile ü Male (neutered) ü Older cat > 4 years ü Obese ü Persian, Himalayan, Burmese ü Indoor, urban ü More acid urinary p. H

Feline Lower Urinary Tract Disease Calcium oxalate Medical history ü History of calcium oxalate, documented by quantitative urolith analysis ü No response to appropriate dietary struvite therapy ü Inappropriate use of urinary acidifiers

Feline Lower Urinary Tract Disease Calcium oxalate ü Treatment Surgery ü Prevention Avoid dietary and medical risk factors

Feline Lower Urinary Tract Disease Calcium oxalate Dietary risk factors ü Excess vitamin C & D ü Acidification ü Ad libitum feeding ü Moderate protein = protective ü Very low protein = risk factor ü Low fiber ü Feeding dry ü Excessive Ca & P restriction

Feline Lower Urinary Tract Disease Calcium oxalate Nutrient profile ü Potassium citrate ü Urinary p. H 6. 6 -6. 8 ü Increased moisture ü Pyridoxine (vitamin B 6) ü Soluble fiber ü Moderate magnesium

Feline Lower Urinary Tract Disease Struvite Mg - NH 4 - PO 4. 6 H 20 ü Magnesium ü Ammonium ü Anionic phosphate

Feline Lower Urinary Tract Disease Struvite Dietary management ü Reduced magnesium Less than 20 mg/100 kcal ME Less than 0. 1% (dry matter) ü Increased diuresis Water Sodium

Feline Lower Urinary Tract Disease Struvite Dietary management ü Acid urine p. H ü Avoid over-acidification Metabolic acidosis Renal disease ü Dissolution - urinary p. H 5. 9 - 6. 1 ü Prevention - normal acid urinary p. H 6. 2 -6. 4

Canine and Feline Urolithiasis Urinary acidification üDecrease in urine p. H from 8. 5 to 5. 5 + 3 NH 4 - 1000 x Increase 33 PO 4 - 13 000 x decrease üModerately acid urine 3 p. H : 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 Disease Struvite Dietary management ü Feed calculolytic diet exclusively ü 1 - 2 months ü Longer if UTI is present ü If no reduction of calculi after 2 months, surgery should be considered

Canine Urolithiasis Struvite Mg - NH 4 - PO 4. 6 H 20 Crystal ü Magnesium ü Ammonium ü Anionic phosphate Diet Magnesium Protein Phosphorus

Canine Urolithiasis Struvite - Dissolution Nutrients ü Minimize protein ü Reduce magnesium ü Reduce phosphorus ü Stimulate water intake ü Increase sodium Acidify urine

Canine Urolithiasis Struvite - Dissolution % DM ü Protein ü Magnesium ü Phosphorus ü Sodium ü Urinary p. H Normal Foods 15 - 60 0. 03 - 0. 27 0. 41 - 2. 43 0. 11 - 2. 22 6. 7 - 8. 3 Calculolytic Diet 7. 6 0. 02 0. 10 1. 28 5. 9 - 6. 1

Canine Urolithiasis Struvite - Dissolution ü Feed calculolytic diet exclusively ü Treat urinary tract infection ü Continue treatment till 4 weeks after radiographic dissolution

Canine Urolithiasis Struvite - Dissolution Monthly evaluation ü Radiography ü Serum urea nitrogen (SUN) ü Urinalysis: crystals, culture bacteria Owner compliance ü Struvite crystalluria ü SUN > 10 mg/dl

Canine Urolithiasis Struvite - Dissolution Reasons for failure ü Insufficient time ü Non-compliance by owner ü Urinary tract infection ü Non-Struvite urolith

Canine Urolithiasis Struvite - Treatment Indications for surgery ü Obstruction ü Anatomical defects ü No response to medical treatment ü Diet is contraindicated

Canine Urolithiasis Struvite - Treatment Diet contra-indications ü Sodium retention Heart failure, hypertension, liver disease, nephrotic syndrome ü Increased protein requirements Pregnancy, lactation, growth, cats ü Acidifing diet Renal insuff. , metabolic acidosis, growth, Ca-ox.

Canine Urolithiasis Struvite - Prevention of recurrence ü Urinary acidification ü Moderate reduction of protein, Mg, P ü Moderate sodium level

Canine Urolithiasis Calcium oxalate Treatment ü Surgery ü Hydropropulsion

Canine Urolithiasis Calcium oxalate Verminderen uitscheiding bouwstenen • Calcium Ca-opname + Calciurie Vitamine D 3: Ca aborptie + indirect calciurie P: te laag: stimulatie Vit D 3 Na: stimulatie calciurie Zure urine: stimulatie calciurie • Oxalaat: spinazie, rubarber, chocolade

Canine Urolithiasis Calcium oxalate Verhogen inhibitoren • Magnesium • p. H urine: Alkalinserend: vb. K-citraat Dierlijke eiwitten verzuren: hoge eiwitopname vermijden Andere: wateropname

Canine Urolithiasis Calcium oxalate - Prevention of recurrence ü Avoid excessive intake of protein ü Low calcium intake ü Low oxalate intake ü Low sodium intake ü Avoid urinary acidification ü Potassium citrate

Canine Urolithiasis Calcium oxalate Prevention of recurrence ü Advanced renal failure diet

Canine Urolithiasis Ammonium urate - Treatment Dissolution ü Dietary management ü Allopurinol ü Urinary tract infection

Canine Urolithiasis Ammonium urate - Treatment Allopurinol Meat diets Purine / Pyrimidine (Nucleic acids & Cell nuclei) Xanthine + Xanthine oxidase Uric acid + Allantoin Uricase (Defect in Dalmatians)

Canine Urolithiasis Ammonium urate - Treatment Dietary management üAmmonium - Low protein üUrate - Low purine Muscle & organ tissue = high in purines Egg & casein = low in purines üAlkalinize urine

Canine Urolithiasis Alkalinize urine H + NH 4 + NH 3 + Decreases NH 4 concentration

Canine Urolithiasis Ammonium urate - Treatment üAdvanced renal failure diet ü 8 - 11 weeks required for dissolution üMonitor for urethral obstruction

Canine Urolithiasis Ammonium urate - Prevention of recurrence üAdvanced renal failure diet Low in protein & purines Alkalinizing the urine üAllopurinol

Canine Urolithiasis Cystine - Composition = Cysteïne - Cysteïne Genetische afwijking: gestoorde reabsorptie van Cystine: weinig oplosbaar Ornithine Lysine wateroplosbaar Alanine

Canine Urolithiasis Cystine - Treatment Surgery Dissolution

Canine Urolithiasis Cystine - Treatment Dissolution ü Dietary management ü D-Penicillamine ü 2 -MPG (Thiola) ü Urinary tract infection

Canine Urolithiasis Cystine - Treatment Dietary management ü Low Protein Low in cystine, cysteine ü Low sodium ü Alkalinize urine ü Advanced renal failure diet

Canine Urolithiasis Cystine - Treatment üDissolution Cystine + D-Penicillamine or 2 -MPG D-Penicillamine-Cysteine 2 -MPG - Cysteine Solubility x 50

Canine Urolithiasis Cystine - Treatment üUrine p. H Solubility 1. 0 x 1. 3 x 2. 0 x Urine p. H 7. 0 7. 5 8. 0

Canine Urolithiasis Cystine - Prevention of recurrence üInborn error do not breed üAdvanced renal failure diet ü 2 -MPG 15 mg/kg BID or ü D-Penicillamine 10 mg/kg BID

Gemengde stenen Ca-oxalaat & struviet Primair vs. secundair Ca-oxalaat irritatie - ontsteking secundaire infectie Struvite ureasevorming p. H & NH 4+

Canine and Feline Urolithiasis Conclusion ü Correct differential diagnosis is important for success of treatment ü Urolithiasis has an underlying cause which should be further investigated ü Dietary versus surgical treatment is decided based on stone type, location and medical factors.

Canine and Feline Urolithiasis Conclusion ü One diet can not work for all types of uroliths ü Preventive diets should provide balanced nutrition ü Avoid over-acidification of the urine