Wonderful photos of your dogs there Tarimoor. Lovely dogs.

No point in OP beating themselves up for what's already done and gone now. At least they have a bit more info to work on in the future.

I'd had dogs for many years before I even heard about this 'not walking pups too far when they are young' stuff. But then I wasn't in the habit of jogging or doing marathons with them but had walked young dogs a few miles at my walking pace. If they got tired I picked them up!

Once I knew about it I acted accordingly with my last two dogs. I was even told you shouldn't let them go up and down stairs until a certain age when I got my CKCS? Something to do with their legs forming?

Stairs not a problem here - got a lift!