Our dog was diagnosed with this today. She had xrays which ruled out hip dysplasia, but she was found to have this cruciate ligament problem--not a complete tear, and the doctor put her on bed rest for a month (well, actually non-bed rest, since she usually gets in bed with us and now she isn't supposed to do stairs.)
Have any of you had a dog with this problem, and what did you do? She is on rest and carprofen for a month.