Earlier today I was giving my my 8 year old sibe a bath when I noticed that there was blood coming from her anal area. Upon inspection I saw a little blood blister like thing in the 2 o'clock position( this one was slightly swollen) and then some other very small but similar spots at what seemed to be the 7pm position. The area wasn't hard or stiff. I proceeded to finish the bath and I walked her for about a mile as well, immediately after. I then took her to the vet and they checked her out. They said everything seemed normal internally. She's kept her appetite, drinks water normally, her stool was completely normal meaning no discoloration or blood and no diarrhea. The vet gave an ointment and some antibiotics. What could this be?