HYPERAEMIA, INFLAMMATION AND FEVER. 67 



high. Normal temperature of adult cattle varies from lOO to- 

 102.5 degrees ; of sheep from 100 to 104 degrees. Nervous sys- 

 tem has control of both heat production and heat loss. The bodv^ 

 temperature is therefore a balance or relation between heat pro- 

 duction and heat loss. 



Heat production. — The source of animal heat is the oxida- 

 tion of body tissue and fuel materials in the blood and the con- 

 sequent breaking up of complex chemical compounds into simpler 

 ones. The principal heat furnishing organs are the muscles and 

 secreting glands. 



Heat expenditure. — Body heat is normally expended about 

 as follows: warming food and drink, 2%; warming air in lungs, 

 5% ; evaporation from lungs, 8% ; evaporation of moisture from 

 the skin surface and radiation from skin, 85%. The expenditure 

 of heat in evaporation of moisture from the skin surface is very 

 much larger than either of the others. On an average there 

 is sufficient heat developed daily in a body of a medium sized 

 horse to raise 4,550 gallons of water 1.8 degrees F. 



Symptoms of fever. — (a) Elevation of temperature; (b) 

 dry, hot skin (not always present) ; (c) pulse and respiration 

 quickened (normal pulse of horse, 36 to 45; normal respiration 

 8 to 14 per minute) ; (d) scanty urine; (e) loss of flesh. 



Kinds of fever. — Classified according to course are: (a) 

 continuous, with but slight variation; (b) remittent, varies great- 

 ly during the day, but does not get down to normal; (c) inter- 

 mittent, in which the temperature varies at different portion* 

 of the day and reaches normal at a certain time each day; (d) 

 relapsing, fever comes at certain intervals, with a period of one 

 or more days of normal temperature between. 



Stages of fever. — (a) The initial, or beginning; (b) the 

 acme or highest point; (c) dechne. The initial stage may be 

 either short or long, according to the patient and disease. The 

 decline may be slow or rapid. 



Results. — (a) Emaciation, or general atrophy, more or less 

 severe, according to the duration and height of the fever, and 

 caused by continued unusual oxidation of body tissues; (b) death 

 may occur, or; (c) recovery. Death may occur suddenly, or the 

 final changes may occur gradually. The recovery may be par- 



