Water intake in domestic rabbits (Oryctolagus cuniculus) from open dishes and nipple drinkers under different water and feeding regimes.

Rabbits (Oryctolagus cuniculus) are often presented suffering from urolithiasis. A high water intake is important in the prophylaxis of uroliths. We investigated the influence factors for water intake using 12 rabbits subjected to different feed and water regimes with practical relevance: Hay, fresh parsley, a seed mix and two different pelleted feed were offered in diverse combinations. Water was provided either by open dish or nipple drinker. Water was accessible ad libitum except for four treatments with 6 h or 12 h water access. Under the different feeding regimes, the drinker had no influence on water intake, but faecal dry matter content was significantly higher with nipple drinkers [60.0 ± 2.1 vs. 57.2 ± 2.1% of wet weight (mean ± 95% confidence interval), p = 0.003]. Dry food led to a higher drinking water intake but total water intake was still lower than with addition of 'fresh' food. With restricted water access, rabbits exhibited a significantly higher water intake with open dishes compared with nipple drinkers (54.9 ± 9.8 vs. 48.1 ± 8.2 g/kg(0.75) /day (mean ± 95% confidence interval), p = 0.04). High proportions of fresh parsley or hay in the diet enhanced total water intake and urine output, and led to lower urinary dry matter content and lower urinary calcium concentrations. Restricted access to drinkers led to a decreased total daily water intake and increased dry matter content of urine and faeces. For optimal water provision and urolith prophylaxis, we recommend a diet with a high 'fresh food' proportion as well as additionally hay ad libitum with free water access, offered in an open bowl.