Ask a Dog Vet and Get Answers to Your Dog Veterinary Questions
Are you able to send a picture of your dog's gums? If I can see it, I may be able to give you some possibilities as to what it is.
sometimes swellings are not harmful and sometimes they indicate that there is something serious going on. However, if your dog is eating well, otherwise comfortable and acting normally then its likely that this is not an emergency and you can address it with your veterinarian at a regularly scheduled appointment.