Canine Calcium Phosphate


These radiopaque stones are similar to calcium oxalate, but are more common in dogs with hypercalcemia.

General Information

Calcium phosphate uroliths (hydroxyapatite, brushite, whitlockite, and octacalcium phosphate) are uncommon in dogs. Common conditions associated with these minerals include hypercalcemia, hyperparathyroidism, hypervitaminosis D, and dystrophic and ectopic mineralization of vital tissues (blood clots, urothelium, etc.).


Calcium phosphate uroliths include apatite, brushite, and octacalcium phosphate. • Serum calcium. Investigate causes for hypercalcemia, when present.


• Correct hypercalcemia based on cause (e.g. parathyroidectomy for primary hyperparathyroidism). • Hydrochlorothiazide with highly recurrent stones (2mg/kg q12-24 hr).


• Lower sodium foods that do not overly acidify urine (e.g. c/d multicare, u/d, g/d, others). If needed, feed canned therapeutic foods or add water to achieve a urine specific gravity less than 1.020.


Urinalysis every 3 to 6 months to adjust pH to 6.5 to 7.5, and urine specific gravity to 1.020 or lower. 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.

Link to Full Recommendation PDF

Canine Calcium Phosphate