The use of P-aminobenzoic acid and chromic oxide to confirm complete excreta collection in a carnivore, Felis silvestris catus

Abstract

Complete excreta collection is a pre-requisite for several protocols in protein metabolism, and lack of confidence in achieving this may be increased when working with carnivores. Recovery of p-aminobenzoic acid (PABA) as a check for complete urine collection and chromic oxide for complete faeces collection were assessed in the cat. A single oral dose of PABA (4 mg/kg BW) was excreted more slowly than has been reported in the human (82% recovery at 6 h). A daily dose of PABA proved a useful method for confirming complete urine collection in the cat, and was 99% excreted in 72 h. Chromic oxide (500 mg/cat) was administered orally and recovery of chromium in the faeces was 90% after 96 h. A HPLC method for the analysis of PABA in cat urine was developed, and from the application of the techniques to a nitrogen balance study, it was concluded that PABA and chromic oxide are useful checks for complete excreta collection in the cat.