Blood changes during the adaptation syndrome in sheep.

Abstract

1. The effect of twice-daily injections of formalin, as an agent eliciting the adaptation syndrome, has been studied on the blood constituents of sheep. 2. Within 4 days of the start of injections of 5 ml. of 4 % formalin there was a significant hypochloraemia, hypoglycaemia and leucocytosis with a return to normal levels after 10 days. There was also an intermediate compensatory hyperglycaemia. The leucocytosis was due primarily to a neutrophilia, although there was a slight transient increase in both absolute lymphocyte and eosinophil counts. 3. When the dose rate was increased to 10–20 ml. of 10% formalin, the plasma chloride and leucocyte patterns were repeated and there was also an increase in erythrocytes and haemoglobin values. In the later stages of the experiment the absolute lymphocyte and eosinophil counts were depressed, whilst the absolute monocyte count had risen. 4. There were no significant changes in blood acetone or in the basophil count throughout the experiment. 5. It is concluded that, in general, the blood changes elicited by an alarming stimulus in sheep are similar to those described in small laboratory animals. The renewed response to an increased intensity of stimulus observed in this experiment indicates that resistance is quantitatively as well as qualitatively specific.