Enhancement of survival in acute experimental fowl typhoid in chicks by the administration of iron dextran.

Chicks aged 15 days were infected orally with 10(6-4) living Salmonella gallinarum. Iron from iron dextran or ferric ammonium citrate (DFe and CFe respectively), in doses of 2-0 or 0-4 mg/kg given intramuscularly at the time of infection, had no effect on subsequent mortality compared with infected controls. Increasing the amount of CFe to the maximum (20 mg/kg) that was non-toxic intramuscularly was also ineffective but when the dose of DFe was increased to 20 or 50 mg/kg the survival rate rose sharply. If given at other times in relation to the time of infection, or more frequently, 50 mg/kg or more of DFe was less active. The increased survival rate among infected chicks given 50 mg/kg of DFe at the time of infection was accompanied by decreases in the severity of the morbid changes in the disease, and by reductions of between c 10- to 100-fold in the numbers of viable S gallinarum in the liver, spleen or blood at the height of the acute infection. DFe (50 mg/kg) given at the time of infection also eliminated the difference in the survival rate noted previously between infected chicks fed respectively with diets containing fish or meat meal as the sole source of supplementary protein.