HEAT PRODUCTION IN RELATION TO BODY WEIGHT AND BODY SURFACE. INAPPLICABILITY OF THE SURFACE LAW ON DOGS OF THE TROPICAL ZONE

Abstract

The heat productions of 65 dogs (from 3.400-31.300 kg.) were esti-mated from the O2 consumptions. Thirty-one detns. were carried out on trained dogs under basal conditions and 59 on dial-morphine anesthetized dogs, in Sao Paulo, Brazil. The minimal heat production was found to be much more constant/ kg. than square meter, and to be expressed by the equation C = 2.00 W0.90. The above results are in contrast to those of other investigators who have uniformly found the heat production of dogs to be more constant when referred to a 0.66-0.74 power of the wt. than to the body wt. itself. Although feeling that a reinvestigation of the heat production of dogs in cold climates is needed, the writer presents an interpretation of the divergent results, upon the view that the Rubner-Richet surface law, being applicable only in cold climates, has a causal thermal significance.