posted 12 years ago
In the wild, the abscess would break open and drain, or if it didn't, the animal would run the risk of a fatal infection (septicemia). If you take the animal to a vet, he is going to lance the abscess, drain the purulent fluid and administer antibiotics. You can do this yourself if you observe sterile technique, and 99% of the time that will work. Then there is always the other 1% when everything goes wrong and you end up with a dead pig.
As far as pain it can vary. Some zits are not noticeable until you look in the mirror. Others hurt like hell.