If they are crying more and yawning there is a problem. A content puppy does not make any noise (except sometimes when they sleep).
The yawning probably is lack of oxygen. I think you did the right thing by giving them a little more air flow.. you may have had it too hot.
Hopefully they all haven't aspirated on the milk. You can do the "downward swing" to them to hopefully get the fluid out of their lungs. Just hold on tight to them.
Wishing you all the best. Keep us posted on their progress.
__________________ Joanne Gurley's Yorkies |