When is the best time to measure urine pH in dogs with calcium oxalate, cystine and urate uroliths?

Uroliths composed of calcium oxalate, cystine and urate are mitigated by neutral to alkaline urine.  Promoting alkalinuria increases crystal solubility, reduces excretion of calculogenic components, and enhances secretion and activity of crystallization inhibitors. 

Therapeutic diets and supplements are often fed to optimize urine pH to reduce stone recurrence.  However, urine pH is highly variable and a single measurement may not indicate that a desired pH range is sustained for most of the day.  Urine pH can be measured every 2 to 4 hours to track pH, but this is not practical for clinics or clients.  

A study indicated that urine is most acidic in morning before feeding and 8 to 10 hours after feeding (i.e. the fasted state).  When the goal is to sustain a neutral to alkaline urine, the best time to measure urine pH is before meals (in the morning before feeding and 8 hours after feeding).  If urine is close to neutral at these times, then neutrality and alkalinity will likely to be maintained throughout the day and night.   If the urine is too acidic (<6.5), alkalinizing supplements (for example, potassium citrate) can be administered and increased until a desired fasting urine pH is achieved. To facilitate testing at ideal times, offer owners the option to buy a handheld pH meter or pH paper and test urine at home.