HIPAA is the correct term because you are inquiring about private health information and details about their disability. All one needs to know is that the individual is disabled and that the dog performs certain acts to aid in that disabled individual's quality of life and functionality. Going beyond that, is asking for private medical information. HIPAA protects one's right to keep their medical records private. It also protects our rights to not have to disclose that information to private individuals or anyone else without first signing or giving verbal consent, while there.
https://www.hhs.gov/hipaa/for-professionals/privacy/laws-regulations/index.html