Hooray! We've made it to the twelve-week mark after Penny's surgery. The surgeon said after this period we could 'start to return Penny to her usual activities' - whatever that means!
However, the physiotherapist says sixteen weeks is a safer length of time, so I'll go by her recommendation. When I look at this video of Penny walking in the underwater treadmill, I can see that she is still favoring her left rear leg.
So I guess it'll be a few more weeks of the treadmill and of staying on lead whevever she is out of the house. (However, I did let her walk beside me off-lead down a local lane today, because it is quiet and straight and not too interesting. It was so-o wonderful to have her walking free beside me.)
The vet nurse who supervises the treadmill says that the water takes seventy percent of the dog's weight, so the treadmill gives her a chance to walk steadily for fifteen minutes, and of course the warm water not only provides resistance and muscle-building capactiy, but it's also comforting for a sore or aching leg.