670 
PHYSIOLOGY 
Figure 4. — Dog running on treadmill while expired gas is collected. 
tered in a permanent record tape file and stored 
for future recall and analysis. 
Measurements were performed on adult, pure- 
bred Beagle dogs maintained in a closed colony 
at an elevation of approximately 1680 meters 
where the barometric pressure was 624 ±: 2 
mm Hg, resulting in an inspired P02 of approx- 
imately 120 mm Hg. 
The means, standard deviations, and ranges 
of pulmonary function parameters measured at 
rest were calculated from single measurements 
on young adult (12 to 14 months) Beagle dogs. 
If results of the first measurement fell outside 
the previously calculated normal range,* the 
dog was retested and the second value, if within 
the normal range, was included in the data con- 
tained herein. Data from equal numbers of male 
* Mauderly, J. L. and Pickrell, J. A., unpublished data. 
and female dogs were included. Since some of 
the parameters may not have a normal distribu- 
tion, arid in order to make as few assumptions 
as possible concerning the distributions, the 
2.5-97.5 percentile ranges were calculated by 
the technique of Herrera.^^ 
Single measurements (no re-testing) of pul- 
monary function at rest were also performed on 
10 male and 10 female Beagle dogs, 7 to 10 
years old. No attempt was made to select indi- 
viduals on the basis of physical fitness although 
none exhibited outward signs of pulmonary dis- 
tress when presented to the laboratory. Means, 
standard deviations, and ranges were calculated 
and the Student T test was applied to determine 
whether significant differences existed between 
values obtained from dogs in the younger and 
older age groups. 
