Thyroactive Iodocasein and Thiouracil in the Diet, and Growth of Parasitized Chicks ,

Induced Hyperthyroidism and Growth of Parasitized Chicks

“…The possibility of a longer latent period in hyperthyroid hosts should be considered, however, since the present coccidial counts were made 3 weeks after exposure. A significant differ-ence in rate of gain by mildly hyperthyroid chicks infected by parasitic worms compared with mildly hypothyroid chicks infected by parasitic worms and with normal infected controls has been reported (Todd, 1948).…”

The effects of thiouracil and thyroxine on the host-parasite relationship of Amplicaecum robertsi Sprent & Mines, 1960, in the mouse

“…fraterna, although the weight gains of the mice were affected; if he increased the dose of the thyroid extract the natural resistance of the old mice was lost. Todd (1948Todd ( , 1949 made a similar study with Ascaridia galli and Heterakis gallinae infections in mildly hypothyroid and hyperthyroid chickens and showed both conditions to have little effect on the resistance of the chicken, although changes in the growth of these worms were noted. Wheeler, Hoffmann & Barber (1948) found that mild hypothyroidism in chickens did not affect their survival when experimentally infected with coccidia.…”

“…Todd (1949) and Whitlock (1949) suggested that alterations of the physiology of the thyroid because of pathological dietary and genetic reasons could contribute to the development of certain differences in the natural and innate immunities observed between individuals and strains of animals to some nematode infections. The bulk of the evidence on mild hypothyroidism and mild hyperthyroidism does not support this view, little effect on the host-relationship being noticed in animals suffering from these conditions (Larsh, 1947(Larsh, , 1950Todd, 1948Todd, , 1949Wheeler et al 1948); more severe treatment with thiouracil and thyroactive compounds have noticeable effects on the resistance of the host. Humphrey & White (1964) say that hypothyroidism is generally associated with a somewhat diminished resistance to infection.…”