Observations of Eviscerated Dogs.

During the course of previous experiments, we have reached the conclusion that the autonomic reorientation underlying the production of fever involves splanchnic stimulation (parasympathetic status) with peripheral inhibition (sympathetic status). 1

During the time of chill the temperature of the muscle remains unaltered, or may be diminished at a time when the rectal temperature is rapidly increasing. 2 With this in mind we have carried out a number of observations on dogs which have been eviscerated according to the method described by Andrews. 3

In our previous experiments we have made use of a continuous injection of a dilute suspension of B. coli. When so injected into the anesthetized animal, a short latent period is followed usually by the onset of a severe chill, which may last either continuously or intermittently for several hours.

In eviscerated animals which we have similarly injected (after the period of recovery following the operation) there was no evidence of chilling, nor was there an increase in rectal temperature. Of course these animals cannot be considered normal because they have a low CO₂ combining power and a very low K/Ca ratio.

We believe that the experiments offer additional evidence that the response of the splanchnic organs is of greatest importance in the production of fever. In eviscerated animals the effect of the bacterial injection on the liver is absent, the peripheral orientation (sympathetic) is not established, and heat loss is not retarded.

If the effect of the bacterial injection were directly on the so-called heat regulating center of the brain, the peripheral effect at least should be undisturbed.

The chart which we present is typical for experiments of this type.