Which food suits a cat prone to urinary crystals?

The right food depends on the crystal type, struvite or calcium oxalate, which behave in opposite ways. A veterinary urinary food aims for dilute urine and a pH matched to the crystal. Identifying the crystal by urinalysis or stone analysis is essential before any choice: a mistargeted food can make things worse (Merck Veterinary Manual; Today's Veterinary Practice). Expert deep dive ### Why does the crystal type dictate the food? Struvite and calcium oxalate are the two most common feline crystals, and they form under opposite conditions: struvite in alkaline urine, oxalate in acidic urine. A diet that acidifies treats struvite but favours oxalate, and vice versa. Choosing the food without knowing the crystal is therefore a gamble (Today's Veterinary Practice). Urinalysis (crystalluria, pH) and, for a stone, laboratory analysis steer the strategy. ### What principle is common to all crystals? Beyond type, diluting the urine benefits all of them: less concentrated urine lowers mineral supersaturation and so the risk of crystallisation. Wet food, fountains and accessible water all help. Surprising fact: since pet foods were reformulated in the 1980s, struvite and oxalate each account for roughly half of feline urinary stones, the balance having flipped over a few decades. The urinary food is chosen with the vet, by the identified crystal and the history. Comparison table | Element | Struvite | Calcium oxalate | |---|---|---| | Forming urine | alkaline | acidic | | Dietary strategy | acidify, restrict magnesium | less acidic urine, dilute | | Identification | urine, stone analysis | stone analysis | | Common lever | dilute the urine | dilute the urine | Petipedia's take Petipedia ties any urinary-food advice to prior crystal identification, referring that diagnosis to the vet.