You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Concentrations of citrate in urine may be important in the aetiopathogenesis of and management of  urolithiasis

In humans low concentrations of citrate in urine (hypocitraturia) is reported to occur in 19-63% of patients with calcium oxalate urolithiasis, but so far the role of citrate in the aetiopathogenesis of canine or feline urolithiasis has not been determined, although hypocitraturia has also been reported in dogs with the disease.

The normal urine citrate excretion in urine (in Beagles) is reported to be : 2.57 +/- 2.31 mg/kg body weight / day

Citrate forms complexes with calcium, presumably reducing the amount of calcium available to form oxalate salts. Citrate also metabolises to form bicarbonate which has an alkalinising effect. Modification of urine pH may assist in increasing citrate concentrations because in normal dogs alkalosis increases urinary citric acid excretion, and acidosis decreases the amount of citric acid in urine. Acidosis also encourages the release of calcium from bone and , and so increases calcium urine excretion, and these two effects together may increase the risk of calcium oxalate urolith formation providing there is sufficient oxalate present as well.

In summary, metabolic alkalosis :

• Decreases citrate uptake into mitochondria
• Decreases oxidation of citrate
• Increases intracellular concentrations of citrate
• Decreases renal  reabsorption of citrate
• Increases urinary excretion of citrate

Metabolic acidosis has the opposite effects :

• Increases citrate uptake in to mitochondria
• Increases oxidation of citrate
• Increases reabsorption in the kidney
• Reduces urine concentrations of citrate

Potassium citrate is widely used to alkalinise urine to prevent the development and/or facilitate the dissolution of cystine, ammonium urate and calcium oxalate uroliths. This can be given as a drug (tablets or liquid) or it may be incorporated into a special diet used to dissolve/prevent  urate uroliths (eg Hill's Prescription diet u/d). Potassium citrate is generally preferred instead of sodium bicarbonate because there is evidence that sodium bicarbonate may increase calcium, sodium urate and cystine excretion into urine.

The recommended dose rate of potassium citrate is :

• 40-75 mg/kg body weight twice daily (dogs)
• 100-150mg/kg body weight /day divided into 2-3 doses (cats)

Warning

The administration of potassium salts to cats should be done with care because hyperkalaemia is a common complication of acidosis, renal failure (advanced) and other conditions.

Updated October 2013