TL;DR: Finding crystals in your cat's urine is a serious warning sign of a potential blockage; schedule a vet visit within 24 hours if they are still urinating, or seek emergency care immediately if they cannot pee.
What are cat crystals and what do they look like?
When you notice a sandy, glittery, or gritty texture in urine left on the floor, you are likely seeing crystalluria. These are microscopic minerals that have clumped together due to changes in urine pH or mineral concentration. The most common types are struvite and calcium oxalate crystals. While they may look small, they indicate a significant imbalance in your cat's bladder health.
Is finding crystals in my cat's urine a veterinary emergency?
- Finding crystals is currently a Medium Urgency situation and a major warning sign that a life-threatening urinary blockage could occur at any moment.
- If your cat is still passing urine, you should contact your veterinarian for an appointment within the next 12 to 24 hours.
- If your cat is straining, vocalizing, or unable to produce urine, this is a High Emergency and requires immediate veterinary intervention.
How does taking a photo of the urine help with my cat's triage?
- A clear photo helps the vet assess the concentration of the crystals and the presence of blood (hematuria).
- Visual evidence helps the team determine the total volume of urine produced.
- A photo allows the clinic to prioritize your cat's care and determines which diagnostic tests, such as a urinalysis or ultrasound, are most urgent.
Clinical Context (Merck Veterinary Manual)
When crystals are found in a cat's urine, the most common types of uroliths to consider are magnesium ammonium phosphate (struvite) and calcium oxalate, although other mineral types are possible. Regardless of the specific mineral composition, diluting the urine is important to reduce the concentration of minerals and crystals that form uroliths. This can be achieved by feeding a canned-food diet and encouraging water intake, such as with water fountains. Medical dissolution is an option for struvite uroliths, but not for calcium oxalate uroliths. Therapeutic diets formulated by major pet food companies are available to manage both struvite and calcium oxalate, although some may be contraindicated in cats with underlying renal disease due to high sodium levels. In cases of ammonium urate or uric acid uroliths, which are less common, dietary management focused on reducing purine intake (especially liver) may be beneficial, although medical protocols for consistent dissolution have not been established.
Chapter: Urology
Source: The Merck Veterinary Manual, 11th Edition (Page 1532)