Also, a supplement for her joints may be helpful, since there's now added strain on her other three legs.
I would recommend Glucosamine Chondrointin, found in the vitamin and supplement aisle at the drug store and this works to help the joints and cartilidge structures, rebuilding them and preventing further degeneration. I've found that the difference is dramatic - to the point where I can tell if one of my dogs hasn't had his medication on time. You'll want to be sure to shop around on this one - It will cost you about $30 per month unless you can find it on sale, which is pretty often. So just shop around. And be sure to check with your vet first, especially if your dog is on any other medications. Also, some supplements of Glucosamine Chondrointin will include an ingredient called MSM. This is an anti-inflammatory supplement and it is safe for your dog. When giving Glucosamine Chondrointin, you'll want to start out with a higher than usual dose and then lower it after two to three weeks (depending on how your dog is reacting). The most commonly prescribed dosage of glucosamine/chondroitin is 20mgs for each one pound of body weight. You can up this to 30 mgs for each one pound of body weight in the beginning. Here is a good article about the use of this supplement in dogs with arthritis and other similar conditions. It even has a helpful product guide that can help you with pricing: http://www.glucosamine-arthritis.org/arthritis-pets/glucosamine-chondroitin-dog-arthritis.html