Can you post pics. I this obvious swelling or just to your trained eye and noticed due to lameness?
If lyme or other type of tick illness that could very well show up as swelling.
What do you feed, any extensive exercise, jumping at squirrels?
Recent vaccines or medications?
He is your friend, your partner, your defender, your dog. You are his life, his love, his leader. He will be yours, faithful and true, to the last beat of his heart. You owe it to him to be worthy of such devotion. - Unknown