Effects of hydrochlorothiazide and diet in dogs with calcium oxalate urolithiasis.
OBJECTIVE
To determine whether hydrochlorothiazide (HCTZ) reduces urinary calcium excretion in dogs with calcium oxalate urolithiasis.


METHODS
Original study.


METHODS
8 dogs with calcium oxalate urolithiasis.


METHODS
4 treatment protocols were evaluated in each dog (a low calcium, low protein diet designed to prevent calcium oxalate urolith formation with and without administration of HCTZ [2 mg/kg (0.9 mg/lb) of body weight, PO, q 12 h] and a maintenance diet with higher quantities of protein and calcium with and without administration of HCTZ). At the end of each 2-week treatment period, 24-hour urine samples were collected. Blood samples were collected during the midpoint of each urine collection period. Analysis of variance was performed to evaluate the effects of HCTZ and diet on urine and serum analytes.


RESULTS
Hydrochlorothiazide significantly decreased urine calcium and potassium concentration and excretion. Hydrochlorothiazide also significantly decreased serum potassium concentration. Compared with the maintenance diet, the urolith prevention diet significantly decreased urine calcium and oxalic acid concentration and excretion. Dogs consuming the urolith prevention diet had significantly lower serum concentrations of albumin and urea nitrogen.


CONCLUSIONS
Administration of HCTZ decreased urine calcium excretion in dogs with a history of calcium oxalate urolith formation. The greatest reduction in urine calcium concentration and excretion was achieved when dogs received HCTZ and the urolith prevention diet. Results of this study suggest that the hypocalciuric effect of HCTZ will minimize recurrence of calcium oxalate urolith formation in dogs; however, long-term controlled clinical trials are needed to confirm the safety and effectiveness of HCTZ.
Lulich
J P
JP
Minnesota Urolith Center, College of Veterinary Medicine, University of Minnesota, St Paul 55108, USA.
Osborne
C A
CA
Lekcharoensuk
C
C
Kirk
C A
CA
Allen
T A
TA
D000821:Animal Feed; D000818:Animals; D002118:Calcium / Q000652:urine*; D002129:Calcium Oxalate; D002136:Calcium, Dietary / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage; D004232:Diuretics; D004283:Dog Diseases / Q000188:drug therapy* / Q000517:prevention & control; D004285:Dogs; D005260:Female; D006852:Hydrochlorothiazide / Q000627:therapeutic use*; D008297:Male; D019815:Oxalic Acid / Q000652:urine; D011188:Potassium / Q000652:urine; D049993:Sodium Chloride Symporter Inhibitors / Q000627:therapeutic use*; D014545:Urinary Calculi / Q000188:drug therapy / Q000517:prevention & control / Q000662:veterinary*
D002136:Calcium, Dietary; D004044:Dietary Proteins; D004232:Diuretics; D049993:Sodium Chloride Symporter Inhibitors; D006852:Hydrochlorothiazide; D002129:Calcium Oxalate; D019815:Oxalic Acid; D011188:Potassium; D002118:Calcium