with hypercalcaemia, which can caused by Addison's disease or certain types of cancer. Hypercalcaemia results in hypercalciuria, which can also be caused by Cushing's syndrome or hyperparathyroidism. There is no recommended diet to dissolve calcium oxalate stones. For prevention a diet low in protein and oxalates and high in magnesium, phosphorus, and calcium is recommended. Increased dietary magnesium and phosphorus decreases the amount of calcium in the urine, and increased dietary calcium reduces absorption of oxalates from the intestines. Potassium citrate has been recommended to prevent calcium oxalate stone formation because it forms a soluble complex with oxalates and promotes the formation of alkaline urine. Dog breeds possibly prone to calcium oxalate stones include Miniature Schnauzers, Lhasa Apsos, Yorkshire Terriers, Miniature Poodles, Shih Tzus, and Bichon Frises. They are the most common stone in male dogs. Calcium oxalate stones are also common in domestic rabbits. Rabbits are prone to hypercalciuria due to intestinal absorption of calcium not being dependent on vitamin D and a high fractional urinary excretion of calcium. The urine will appear thick and creamy or sometimes sandy. Small stones and sand can be removed using urohydropropulsion. Prevention is through reducing calcium intake by feeding more hay and less commercial rabbit pellets, and by not using mineral supplements. Frequency of struvite and calcium oxalate stones in cats The Minnesota Urolith Center at the University of Minnesota College of Veterinary Medicine has done detailed analysis of uroliths from animals since 1981 and has noted changing trends in feline uroliths. In 1981, struvite stones were the most common type in cats, making up 78 percent of submitted samples, with only 2 percent comprising calcium oxalate stones. In the mid 1980s there was a substantial increase in the number of calcium oxalate samples, and between 1994 and 2002, 55 percent of feline stones were calcium oxalate and 33 percent were struvite. This may have been caused by the use of dissolution diets for struvite stones in cats and modification of other diets to prevent struvite crystal formation. These modifications predisposed to calcium oxalate crystal formation. However, in 2004, struvite stones once again surpassed calcium oxalate stones 44.9 percent to 44.3 percent, and in 2006, 50 percent of stones were struvite and 39 percent were calcium oxalate. This may have been due to the increased use of diets designed to prevent calcium oxalate crystal formation, which because of increased magnesium in the