Office of Aerospace Medicine Technical Reports

FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute


Report No: DOT/FAA/AM-84/5

Title and Subtitle: Tolerance endpoint for evaluating the effects of heat stress in dogs

Report Date: June 1984

Authors: Hanneman GD, Sershon JL

Abstract: Animals occasionally die from heat stress encountered during shipment in the nation's transportation systems. To provide a basis for a series of studies on shipping crates, environmental conditions, etc., as may be encountered in air transport of dogs, we sought to establish a suitable tolerance endpoint for heat/humidity stress in dogs. We monitored the heart rate, respiratory/panting rate, and rectal temperature of 10 male beagle dogs exposed to an air temperature of 95 + or - 1 F (relative humidity 93 + or - 2 percent) for less than 24 hours.

Of the first six animals, two died during exposure, two died after being removed from the test chamber, and two survived a 24-hour exposure. Based on observations from these six dogs, a rectal temperature of 108 F was tentatively chosen as the tolerance endpoint for subsequent tests. Of four additional animals tested, two were removed from the environmental chamber when their rectal temperature reached 108 F and the two others finished the test with a rectal temperature not exceeding 102.7 F. No ill effects were noted in any of the surviving six animals during a 7-day post-observation period.

These and subsequent findings indicate a rectal temperature of 108 F can be safely tolerated and can serve as a tolerance limit for additional studies of heat and humidity effects on dogs.

Key Words: Heat stress, Environmental stress, Animal physiology, Heat tolerance endpoint, Beagle dogs, Animal shipment

No. of Pages: 31

Last updated: Friday, June 1, 2012