My Poor Kayla

I am not sure what happen to my little girl, but she started babying her left paw about 3 weeks ago. Jim took her to the vet, and we found out that she had an infection in the joint on her wrist. She's been on 2 antibiotics for over a week now, and now she isn't using the paw at all and the swelling is still there. I have to take her back to the vet on Friday morning for them to check it out again. She just seems so depressed and lays around here all day long. Even when people come to visit, she used to go nuts wagging her tail and running around... now it's a simple tail flip and then she just puts her head back down where ever she was laying and goes back to sleep. My poor baby. I hope it's nothing very serious... but it does have me worried. She's only 8 years old... I know she's not a spring chicken, but she's no old maid either! Oh Kayla... please cheer up buttercup!