> Has ANYONE had such frailty,
My pup went lame at 5 months old, he got worse & worse, it turned out to elbow displasia but it seemed to effect his back legs to (they were x-rayed - nothing wrong with them). He could hardly walk 4 yards :(
He was on Metacam and every day I took him out for a walk. To start with he only went a few steps and we didn't get much further than the end of our small front garden, but slowly it was increased. He is now 9 months old and he rarely limps atall (if he does limp it is so slight that somebody who didn't know he had the ED wouldn't be able to see it). At the begining of the year he couldn't walk from the kitchen to the garden, now he goes on a 30 min walk every day on a long line!!!! He has improved so much that an opperation for the elbow displasia is something that is not on the cards in the near future :)
Glucosamine has also helped loads.
I'm not trying to say your pup has ED, just that at 5 months old they still have so much growing to do it is amazing the improvements they can have as they get more muscle & get stronger with controlled exercise.
I really hope you get to the bottom of it soon. I know how heartbreaking it is to see a puppy that can hardly walk :( But I have 1st hand experience of a puppy going from 'can't walk' to 'try & stop me'!!!! :)