We have a labrador that all of a sudden one day couldn't walk. Turns out she had hip dysplasia. :(
She ended up having to have a surgery called Femoral Head Ostectomy. They cut the femoral head of the leg bone off and the scar tissue created an artificial hip joint. She is fine now and runs and plays with the other dogs.
I hope your dog doesn't have hip dysplasia. We paid $700 for her surgery. This was a dog we got off of Freecycle! :rolleyes:
It was worth it to us though. She's the sweetest dog we have ever had. :)