Ideally you lift a large dog by having one arm across in front of their chest, and the other arm under their tail and across the bum. The legs then dangle down between. It's like how you would carry a lamb.
This stops any compression of the rib cage or squeezing of the belly. However, if you are a distance from the car and you tried to walk too far like this you are likely to buckle at the knees and drop the dog.
It might sound off the wall but check out how to do a fireman's lift.
If you have a large dog (who is not struggling too much or is unconscious) that you need to carry in an emergency, yet still keep a hand free to control another dog on a lead or just to carry anything, then a fireman's lift can work as well as for humans. The difficult part would be getting them up on your shoulders but, if it was an emergency, then it is surprising how much inner strength you can find.
It's probably not ideal because you would have to be very careful not to compress the ribs so the dog breathed properly but in an emergency it might be a life saver.
I always remember my Dad walking back up the road with the body of our huge German Shepherd round his shoulders after he fell down a floor into a cellar on a building site following Dad
http://www.google.co.uk/url?sa=t&source ... hf4yS7DgFQ
I've tried this out on Jack, who weighs about 25kg, and he was quite happy and relaxed across my shoulders but Becky wasn't having any of it

I think she would need to be out for the count before she allowed me to sling her over my shoulders.
