Struvite crystals used to be the most common urinary crystal by far. Diets were developed to minimize the risk of developing struvite crystals; this did decrease the number of cases of struvite crystals, but increased the incidence of oxalate crystals. Struvite crystals are still the most common type, but calcium oxalate has closed the gap in the last twenty years.
If your cat has oxalate crystals, treatment can include:
- Balancing urine pH. Calcium oxalate stones are more likely to form in urine that is acidic. The recommended pH level for feline urine is between 6 and 6.5. A more acidic urine can encourage the development of oxalate crystals. High levels of vitamin C can also acidify urine — so avoid giving foods with high levels of vitamin C to a cat who is prone to oxalate crystals.
- Increasing water consumption. The more your cat drinks, the less concentrated his urine will be. This means crystals are less likely to form. This also means the urine will spend less time in the bladder (another way to decrease the chance of crystals forming). Experts suggest providing fresh, clean water at all times — and in several locations around the house.
- Balance levels of calcium in the diet. Calcium levels that are too high can increase the risk of calcium oxalate crystal formation. Watch calcium levels in the diet and vitamin D intake. However, too little calcium can also be a problem — when dietary calcium is low, the body absorbs less oxalate, leaving more in the urine.
- Balance levels of phosphorus in the diet. Phosphorus levels affect calcium levels. If your cat is getting too much or too little phosphorus, calcium levels may be off.
- Balance levels of magnesium in the diet. If your cat is getting too much or too little magnesium, he may be at greater risk for developing oxalate crystals.
Talk to your vet about appropriate levels of calcium, phosphorus, and magnesium in your cat’s diet.