Coli fever and blood volume in dogs

Abstract

For the continuation of work on the mechanism of fever reduction by drugs we have been seeking a satisfactory method of producing fever in dogs. In these animals a predictable curve of neurogenic fever is very difficult if not impossible to obtain. A few injections of peptone have given us a maximum rise of less than 1° C. with a rapid return to normal within two or three hours (maximum dose employed: 7 c.c. per kilo of 67 per cent. “bactopeptone.”)

Turning to injections of killed cultures of colon bacilli we made nineteen experiments with subcutaneous injections of a vaccine containing 325,000 million bacilli per c.c. and in fourteen of these obtained a temperature the following morning (that is, after 15 hours), varying from 0.4° to 1.7° C. above normal. In the other five, no elevation of temperature was seen.

The next procedure was to inject in the morning, following the curve throughout the day. For this purpose a more concentrated vaccine was selected, containing 1,625,000 million bacilli per C.C. In five uncomplicated experiments in which this vaccine was used, maximum temperature increases of 2.4° to I.5° C. (with hourly readings) were obtained with doses of I C.C. per kilo. With C.C. per kilo the maximum increase was 2.4°. A smaller dose (0.2 C.C. per kilo) gave, however, an increase of only 0.6° C. A third strength of vaccine used contained one million bacilli per c.c.; doses of and I C.C. per kilo, gave maximum increases of 1.0° and 1.2° C. respectively. In all of the experiments with the last two vaccines the maximum temperature was attained by either the second or the third hour after the subcutaneous injection. At the end of the day (6-8 hours after injection) the temperature elevation was usually reduced by about one half.