Taurine deficiency in the developing cat: persistence of the cerebellar external granule cell layer

Dietary taurine deprivation adversely affects feline pregnancy and is associated with the frequent occurrence of fetal resorption, abortion, stillbirth, and low birthweight of live kittens at term. Taurine-deprived, live-born kittens have a poor postnatal survival rate and grow less well than kittens from taurine-supplemented queens. The postnatal dietary taurine intake of such kittens is reduced if they are nursed by their biologic mothers; the concentration of taurine in milk of taurine-deprived mothers is less than 10% of that in milk from taurine-supplemented queens. Surviving kittens from taurine-deprived mothers exhibit a constellation of neurological abnormalities (abnormal hind leg development, a peculiar gait characterized by excessive abduction and paresis, and thoracic kyphosis readily visible by X-ray). These findings suggest the presence of a developmental cerebellar deficit. Histological examination of the pre- and postnatally taurine-deprived kitten's cerebellum reveals a persistence of the external granule cell layer, which was confirmed by electron-microscopic examination. Numerous mitotic figures are present in the cells in the external granule cell layer of the cerebellum of kittens born from the nursed by taurine-deprived queens, but not in those from taurine-supplemented mothers. These findings suggest a maturational delay.