My daughter works for a vet and is studying to be one. She said if it is severe enough to swell then there may be what is called "pocketing" underneath where the subcutaneous space is open and it fills with fluid. She said if it where her dog she would take it in to the vet and probably get a NSAIDs. I didn't know what that meant so I texted her back and she texted, Non Steroidal Anti Inflammatories.

Thats the best I can offer and I hope you dog mends quickly.