Urine pH
Urine ·Also called: pH, urine pH, urinary acidity
What it is
pH runs from acidic at the low end through neutral at 7 to alkaline at the high end. Urine pH reflects diet, how long the sample has been standing, whether bacteria are present, and the body's overall acid-base state.
Why your vet measures it
Crystal and stone formation is pH-dependent. Struvite forms in alkaline urine and dissolves when the urine is acidified; calcium oxalate forms in acidic urine and cannot be dissolved, only removed. So the pH steers both prevention and treatment.
What a high result can mean
- A urinary tract infection with bacteria that split urea and alkalinise the urine
- A sample that has been standing at room temperature for too long
- A vegetarian or cereal-heavy diet
- Certain kidney tubule disorders
What a low result can mean
- A normal, meat-based diet
- Urinary acidifying diets, often prescribed to dissolve struvite
- Metabolic acidosis from illness
- Prolonged fasting
Dogs and cats differ
Struvite stones in cats are usually sterile and diet-related, while in dogs they are usually driven by a urinary infection — so an alkaline pH in a dog prompts a urine culture, and in a cat prompts a diet review. Calcium oxalate has become the more common stone in both species in recent years.
Questions worth asking your vet
- How soon after collection was this sample tested?
- Given the pH and any crystals found, what stone type are we guarding against?
- Does the diet need changing?
Related terms
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