The Effect of Continuous and Pulse Dose Ammonium Chloride Regimens on the Urine pH of Goats

Abstract

Ammonium chloride (NH4Cl) has been the primary preventive modality for struvite urolithiasis in goats. This study investigated the effect of continuous and pulse dose NH4Cl therapeutic regimens on urine pH in ten goats.

The initial regimen (feed additive) consisted of 0.007% NH4Cl as a feed additive. Following this week long regime, the two treatment regimens were designed as a standard ten goat cross-over design. The first treatment regimen (continuous) consisted of daily administration of a titrated dosage of NH4Cl for ten days, followed by four days without treatment. The third treatment regimen (pulse) used daily administration of a titrated dose of NH4Cl for three consecutive days followed by four days without treatment for three treatment periods. Ammonium chloride dosages were titrated to result in a urine pH of < 6.5 (target level) prior to commencing treatment regimens. Urine pH was evaluated once daily during feed additive regimen and twice daily during the treatment regimens.

A Bayesian methodology was used to determine the daily odds ratios for production of target urine pH during treatment regimens. The odds ratios were also calculated between pulse dosages during the pulse regimen. The feed additive regimen did not result in target urine pH within 7 days. Treatment with the continuous regimen resulted in target pH, however, pH returned to >6.5 within five days, (odds ratio 0.23-1.56 at Treatment Time 10). The odds ratios for each pulse period of the pulse dose regimen were 2.20-7.45, 0.41-1.68 and 1.59-5.62 respectively. The results of this study indicate that variability in response to therapy warrants titrating individual dosages of NH4Cl, continuous therapy results in a loss of effectiveness, and pulse dosage is effective in repeatedly producing a urine pH of <6.5.