Uroliths with calcium oxalate (CaOx) and urate indicate that two diseases processes are occurring concurrently or in succession. The primary etiology underlying both minerals in most cats is unknown. Hypercalcemia and defects in urate metabolism (hepatic portosystemic shunt) should be investigated since these diseases have a definitive treatment.
• Serum calcium and serum bile acids. Investigate causes for hypercalcemia, when present.
• Correct hypercalcemia based on cause (e.g. food change, prednisone, parathyroid removal, etc.).
• Potassium citrate if urine pH is consistently ≤6.5 (starting dose: 75mg/kg q12-24h).
• Lower purine/protein/sodium foods that produce neutral or alkaline urine (e.g. Hill’s k/d early support, k/d, others). If needed, feed canned therapeutic foods or add water to achieve a urine specific gravity ≤1.030.
Urinalysis every 3 to 6 months to adjust pH to 6.5 to 8.0, and urine specific gravity to less than 1.030. Medical imaging every 6 to 12 months to detect recurrent stones when small to potentially permit their removal without surgery.