Re: Husbands/Wife’s right to know
Hippos don’t take any oaths. 
It’s Hippocratic oath.
"For example, let us say a below-age of consent](Age of consent - Wikipedia) girl came to a doctor with a sexually transmitted disease. The doctor is usually required to obtain a list of the patient’s sexual contacts to inform them that they need treatment. This is an important health concern. However, it is likely that the girl might reveal her partners were older, and this could result in a fear that they would be charged with a crime such as *statutory rape](Statutory rape - Wikipedia). In some jurisdictions, the doctor cannot be forced to reveal the information revealed by his patient to anyone except the appropriate health authorities, and they too are required to keep that information confidential. If, in the case, the police become aware of such information, they are not allowed to use it in court as proof of the sexual conduct.*
In the United States, the extent of the privilege varies depending on the law of the applicable state. For example, in Texas there is virtually no meaningful physician-patient privilege in criminal proceedings, and the privilege is limited in civil cases as well. See generally Texas Occupations Code section 159.003 and Texas Rules of Evidence, Rule 509(b)."
Retrieved from “http://en.wikipedia.org/wiki/Physician-patient_privilege”