Should I be worried about this?

So I came home yesterday, and my dog was badly limping, and her ankle was swollen. I took her to the vet, and we noticed she had a small cut behind her ankle, near the bottom of her foot, that she had obviously been licking for a while, because the fire was orange. They gave me some meds for pain, and inflammation.... show more So I came home yesterday, and my dog was badly limping, and her ankle was swollen. I took her to the vet, and we noticed she had a small cut behind her ankle, near the bottom of her foot, that she had obviously been licking for a while, because the fire was orange. They gave me some meds for pain, and inflammation. I came home today, and shes back to her normal self. Running around, and wanting to play. I noticed on her ankle, there is a large, hard mass. I guess it may have always been there, because that ankle has always looked odd. Anyway, I pressed on it rather hard, and moved her ankle around, and she didnt seem to mind.
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