A quote from the oath:
"I will go into them for the benefit of the sick, and will abstain from every voluntary act of mischief and corruption; and, further, from the seduction of females or males, of freemen and slaves"
Slaves did exist at that time and I think that he is saying that a physician must stay away from seducting women, men and from seducing slaves. It does not say that having slaves is okay.
Joanne