I'd much rather find an animal with a high temp than a low one. :shock:
Experience at the vet clinic has shown that when the temp goes below normal that it's a sign that the animal's immune system has quit fighting whatever bug it is up against. They are really hard to bring back when they get to this stage. Really hard, if not impossible.
They may have had a low grade chronic pneumonia, and not let on until it was really advanced. Sometimes big strong calves can fool you, and if you don't sneak up without them seeing you they won't let on that anything is wrong. As soon as they see you, they pick right up and try and blend in with the rest. It's like they are their own worst enemies. We've had lots that just looked "a little off", and turned out to be able to boil the thermometer when we put them in the chute. It's aggravating to say the least. :? :?
Sometimes the best pen checking is done by peeking around corners. :wink: