What do you do if a spider bites your guinea pig?

Once my guinea pig, Fudge, accidentally bit me on my finger. I thought it was OK but then it started bleeding really badly. I cleaned it up and put some of that Dettol cream on it. Then I put a band-aid on it. the next day I took the band-aid off and it was REALLY swollen so I went to the doctor. I recommend you go to the doctor too because your guinea pig could have a disease or something and it might spread to you. I had to be on medication for two weeks and after that it really cleared up. Don't put a band-aid on it for too long otherwise the bite will not have air to heal it better.