Haematological, serological and pathological effects in chicks of one or more intravenous injections of Salmonella gallinarum endotoxin.

Abnormalities appeared a few hours after groups of 14-day-old chicks (Gallus domesticus) were injected intravenously with 15 mg/kg of endotoxin (LPS) from Salmonella gallinarum. Clinical illness without mortality was accompanied by significant (P less than 0.05) falls in body temperature, bursa weight, the main haematological parameters, serum iron (SI) and transferrin saturation (TS) and a significant increase in unsaturated iron-binding capacity. All responses, apart from bursa weight, SI values and total and differential white-cell counts, returned to normal within 24 to 48 h. LPS given daily for three consecutive days did not cause changes in the main haematological parameters during the 48 h period following the third injection. However body and bursa weight and heterophil counts were significantly depressed, whereas body temperature, SI and TS were affected biphasically, being first depressed and then raised above normal. Chicks injected with LPS daily for six consecutive days showed broadly similar responses but a persistent microcytosis was also present.