There is a Canine Conservative Management Yahoo Group which may be helpful. There are many resources in the files and links sections regarding canine rehab.
I recommend you go immediately to an orthpedic specialist - a vet cannot diagnose this and rule out some things or at least try to get a highly likely diagnosis. A cruciate tear is very different than a sprain, or torn muscle for instance.
The group above would be a good idea as well as OrthoDogs on Yahoo Groups. Both groups have good information in their Files sections....ma
ny many on these two groups can tell you how things go as well and give all the tricks to the trade - exercises, games, stimulation exercises etc.
This is the downside of BigPaws - bad orthos and it is a rough ride. Good luck