kinda hard to believe but back in 2005, I shot a buck at 50 yards in about 6" of fresh snow. It was a perfect shot, double lungs. It was a complete pass through and the buck ran about 60-yards. For the entire distance and where he fell, not a single drop of blood. Not one. Take a look.
Even for the trophy shot, no blood. Maybe it was because it was -17 degrees.
BTW- If you are new to mzl. in extreme cold don't take your gun inside. The condensation in the barrel can cause problems.
Might have had a heart attack but the heart looked healthy. However, both lungs were a real mess. he was Full of blood inside, just didn't have any make it outside. had I not heard him fall and followed his track a little ways, he might never have been found.
That is exactly why I exhaust every effort in trying to find my deer after the shot.
I truly cannot imagine the deer that are lost due to a half hearted follow up! I shotgunned and double lunged my buck this season to find no blood but specs of lung tissue... I thought I missed, further inspection...tissue and small amount of hair kept me going.