Abstract
Generally, in order to collect faeces and urine of cats, the animals are housed in metabolism cages with wire-mesh bases. We have developed an alternative method to collect faeces and urine quantitatively and separately, using cages with solid floors. The use of such cages allows long-term experiments to be carried out without increased risk for injury to feet or legs. Modified litter boxes were constructed so that faeces and urine were separated and the cats could bury their faeces. With the use of this method the excretion of calcium, magnesium and phosphorus by mature cats was determined. Mineral retention over a period of ten days did not differ significantly from zero, suggesting that the method developed is valid for the measurement of mineral excretion. Evidence is presented that under our experimental conditions faeces should be collected for at least five days so as to cancel out largely the impact of day-to-day variation in defecation on the variance of mineral retention.