Guinea pigs are actually prone to abscesses, because their pus
Guinea pigs are actually prone to abscesses, because their pus lacks an enzyme that makes it watery and easy for the body to clear away. It's very thick and rubbery and thus the body can't get rid of it once it accumulates, so it walls it off instead and then an abscess forms. They could be from bites, but not necessarily. I've had three pigs treated for abscesses (though one most probably was actually a sebaceous cyst that was biopsied with a needle and then failed to heal properly and had to be surgically removed. That one was on her lower back.) The other two had abscesses along their jawlines. It's possible that the original source of infection was a hay poke or other minor scrape in the mouth, but it's impossible to know for sure. However, I can vouch that none of them were ever bitten by another animal or had any noticeably surface wound prior to the abscesses forming, so abscesses can definitely arise from a very minor, even invisible, source of injury.
Edited to add: It's probably a good idea to get her checked out. Have the abscesses completely healed? Are they open? It's sometimes possible to remove an entire abscess, including the capsule/pocket of skin around it, and simply pull the skin back over the area. These abscesses are not likely to recur when treated this way. The pig with the lump on her back had the entire thing removed, as there was enough slack in the skin to do a repair. If this isn't possible due to location, abscesses can be lanced and drained surgically, but they need aftercare to allow them to heal from the inside out. Essentially, they need to be left open so that you can irrigate/clean them out, express any new pus that develops, and allow them to fill in from the bottom down. If the pig you're adopting has open abscess wounds, you may need to do aftercare to ensure the abscesses don't reform.
lacks an enzyme that makes it watery and easy for the body to clear away. It's very thick and rubbery and thus the body can't get rid of it once it accumulates, so it walls it off instead and then an abscess forms. They could be from bites, but not necessarily. I've had three pigs treated for abscesses (though one most probably was actually a sebaceous cyst that was biopsied with a needle and then failed to heal properly and had to be surgically removed. That one was on her lower back.) The other two had abscesses along their jawlines. It's possible that the original source of infection was a hay poke or other minor scrape in the mouth, but it's impossible to know for sure. However, I can vouch that none of them were ever bitten by another animal or had any noticeably surface wound prior to the abscesses forming, so abscesses can definitely arise from a very minor, even invisible, source of injury.
Edited to add: It's probably a good idea to get her checked out. Have the abscesses completely healed? Are they open? It's sometimes possible to remove an entire abscess, including the capsule/pocket of skin around it, and simply pull the skin back over the area. These abscesses are not likely to recur when treated this way. The pig with the lump on her back had the entire thing removed, as there was enough slack in the skin to do a repair. If this isn't possible due to location, abscesses can be lanced and drained surgically, but they need aftercare to allow them to heal from the inside out. Essentially, they need to be left open so that you can irrigate/clean them out, express any new pus that develops, and allow them to fill in from the bottom down. If the pig you're adopting has open abscess wounds, you may need to do aftercare to ensure the abscesses don't reform.
