<human>: Summarize the given text in a few sentences.

This is my first time posting here so please be gentle. My girlfriend was walking her 6 year old Corgi-Terrier mix and were both attacked by a dog who's owner's maintenance worker left the gate to their home open. As she was walking by the dog just ran over and started to attack my gf's dog. She attempted to intervene and was also bitten and bruised. The owners (an older couple), ran out and were able to restrain their dog. They were extremely apologetic, bandaged up my gf, and according to her, were even crying they were so upset. They offered to drive her to the hospital, or her and her dog to the vet if necessary, but she declined and left. She checked her dog all over and did not notice any visible wounds or signs of trauma. She kept an eye on her, and other than seeming a bit shaken up, she seemed fine.

The next morning my gf noticed her dog's stomach had small red spots. To me they look like bruises, but she's worried they may be something worse, like internal trauma. Any ideas as to what we should do here? Do we need to take her to the vet? Are these just bruises that will heal? Thank you.
<bot>: My girlfriend's dog was attacked, with no signs of visible trauma. The next morning the dog has red spots on her stomach.