Nutritional Taurine Deficiency and Feline Pregnancy and Outcome

Abstract

The high concentrations of taurine and the function of taurine in excitable tissues have been the subject of speculation for many years. In recent years it has become possible to examine the functions of taurine further by perturbing the concentration in tissues; in the cat by dietary restriction and in rodents by administering the taurine transport inhibitor guanidinoethane sulfonate. Both of these strategies result in reduced tissue taurine concentrations and retinal degeneration. There has been additional interest in the possible functions of taurine in the developing nervous system because taurine concentrations are especially high, taurine generally being the free amino acid present is the greatest concentration in late fetal and early postnatal brain (4). We have explored the role of taurine in development by mating and breeding female cats that had been acclimated to synthetic diets containing various amounts of taurine for long periods of time (more than 6 months). It soon became clear that although taurine-deficient females apparently came into estrus normally and generally appeared to conceive normally, they experienced difficulty in successfully completing pregnancies (5). Reproductive losses included fetal resorption, abortion, stillbirth, and low birthweights (mean birth weight 70 g) of live kittens at term (Fig. 1). Live kittens had a poor survival rate, and grew slowly. Females fed the same diet supplemented with 0.05% taurine did not experience such difficulties (mean birthweight 104 g). Table 1 details the outcome of pregnancies to date.