These stones often have different radiographic layers representing different minerals.
Uroliths with calcium oxalate (CaOx) and struvite or calcium phosphate carbonate (CPC) indicate that two diseases processes are occurring concurrently or in succession. In almost all dogs, struvite and calcium phosphate carbonate form because of urinary tract infection. When infection is consistently prevented, struvite and calcium phosphate carbonate are unlikely to recur. CaOx is a difficult stone to prevent because factors responsible for formation are incompletely understood. Therefore, risk management strategies other than antibiotics are prioritized to minimize CaOx.
• Serum calcium. Investigate causes for hypercalcemia, when present.
• Genetic test for Hereditary Calcium Oxalate Urolithiasis Type 1 in at risk breeds (e.g. English Bulldogs, Boston Terriers, and American Staffordshire Terriers).
• Urine cultures every 1 to 3 months and with urinary signs.
• Administer culture-susceptible antibiotics for 3-7 days for sporadic infections; for relapsing infections-see detailed struvite recommendations.
• Potassium citrate if urine pH is consistently less than 6.5 (starting dose: 75mg/kg q12-24 hr).
• Correct hypercalcemia based on cause (e.g. parathyroidectomy for primary hyperparathyroidism)
• Hydrochlorothiazide (2mg/kg q12-24 hr) with highly recurrent calcium oxalate in normocalcemic dogs.
• Canned lower sodium foods that do not overly acidify urine (e.g. c/d multicare, g/d, i/d low fat, others). If needed, feed canned therapeutic foods or add water to achieve a urine specific gravity less than 1.020.
• Urine culture every 1-3 months and with urinary signs of disease. • Urinalysis every 3 to 6 months to adjust pH to ≥ 6.5, and urine specific gravity to ≤ 1.020. • Medical imaging every 6 to 12 months to detect recurrent stones when small to permit their easy removal without surgery.
We advise reviewing manufacturer's literature regarding selected therapeutic foods to determine indications and contraindications. For pets with multiple health concerns,we suggest that the selection of diet should take into consideration all health needs of the pet.