Studies in detoxication. 82. The fate of benzoic acid in some domestic and other birds.

In most laboratory mammals benzoic acid is converted into hippuric acid and benzoyl glucuronide (see Williams, 1959), except for the cat, which seems to produce only hippuric acid (Robinson & Williams, 1958, and unpublished data). Jaffe (1877) showed that benzoic acid was converted in hens into ornithuric acid, and benzoyl glucuronide has also been found to be a metabolite of benzoic acid in hens (Baldwin, Robinson & Williams, 1959). It has been assumed that ornithuric acid formation is common to most birds, but, as far as we are aware, there is no evidence to support this. Schachter, Manis & Taggart (1955) have shown that pigeon-kidney slices and extracts form glycine conjugates, whereas kidney preparations from the chicken, duck, goose and turkey do not. They also found that chickenand duckkidney powder formed ornithine conjugates. These studies in vitro suggest that ducks as well as chickens form ornithuric acids whereas pigeons form hippuric acids. In the present paper we shall show, with the intact bird, that chickens, turkeys, geese and ducks excrete ornithuric acid after being dosed with benzoic acid, whereas the pigeon and the related wood pigeon and dove excrete hippuric acid. Neither hippuric acid nor ornithuric acid was found in the excreta of a parrot and a carrion crow dosed with benzoic acid. All the birds examined formed benzoyl glucuronide.