Study Start Date: 01/01/2007
Study End Date: 12/31/2007

Evaluation of calcium metabolism and urinary saturation in cats with spontaneously occurring idiopathic hypercalcemia and calcium oxalate urolithiasis

We are looking for cats that have had calcium oxalate bladder stones and idiopathic hypercalcemia (high blood calcium level). The study involves collecting a 24-hour urine sample while cats are consuming 3 different diets and receiving potassium citrate, a drug that increases urine pH that is used in managing calcium oxalate stones. All costs are covered by the project.

Study Design:
Prospective, Cross-over, Randomized.

Sample Size:
12 cats

Inclusion criteria:

1. History of idiopathic hypercalcemia and proven calcium oxalate urinary bladder stones.
2. Willing to come to The University of Tennessee 3 times over 24 weeks.
3. Willing to allow their cat to be hospitalized for 24 hours.

Exclusion Criteria:

1. Cats without a history of calcium oxalate urinary stones or hypercalcemia.
2. Cats will be excluded from the study if they received glucocorticoids, diuretics, or supplements containing calcium or vitamin D within the past 2 years, if they have other diseases that preclude feeding these diets, and if they have hypercalcemia due to a cause other than idiopathic.
3. Inability to come to The University of Tennessee.
4. Difficulty in feeding the 3 diets.

Study Controls:
The study is a 3-way cross-over study where cats serve as their own controls.

Study Endpoints:
Cats will be fed 3 different diets for a period of 8 weeks on each diet. At the end of each feeding period, 24-hour urine samples and blood samples will be collected.

Samples:
No samples will be submitted by referring veterinarians.

Costs/Reimbursements:
Costs of laboratory evaluation and hospitalization is paid for by study. Diets and potassium citrate are provided.

Full Disclosure information:

• The study is funded by a grant from Morris Animal Foundation.
• The investigator has presented Pet-food-company-sponsored lecture on urolithiasis.
• The study will be published if results are negative.
• The study will be reported on VIN.
• The authors will acknowledge VIN if the study is published.
• Owners will need to sign an informed consent form.