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DISCUSSION 
W. Ehrlich, Johns Hopkins, Baltimore, 
Maryland: I wanted to ask you whether you 
had to remove the mask after the dog ran, or 
how did the dog handle temperature regulation ? 
It is known that the only place they can sweat 
or get up air vapor is the tongue. 
Dr. Mauderly: Right. Well, in the first 
place, remember that I mentioned that we're in- 
spiring dry room air so the elimination of mois- 
ture is facilitated in that way. The mask is de- 
signed so that the dog can breathe open 
mouthed. They can pant, they can breathe with 
any pattern they want. The speeds that we se- 
lected -ere partially selected for these reasons. 
Abovfc xjur and a half miles an hour we found 
the dogs breathing with a very rapid, shallow 
panting pattern presumably because of temper- 
ature and moisture regulation. Three miles an 
hour was simply chosen as an intermediate 
speed. Also, four and a half miles an hour was 
the speed which dogs with significant pulmo- 
nary dysfunction in our studies could maintain. 
But the mask is constructed so they can breathe 
open mouthed. There's plenty of room around 
the muzzle. They're on the treadmill actually 
running for perhaps fifteen minutes. The tread- 
mill is level and does not represent a maximal 
exercise. We've done some blood lactate meas- 
urements on the dogs immediately after they 
come off the treadmill and we've found no con- 
sistent increase in blood lactate so it's a very 
mild exercise for the animals. 
R. A. Redding, Brown University, Provi- 
dence, Rhode Island: Three questions. One, is 
rectal temperature measured during your test 
