This is an idea for a diagnostic tool. Dolphins have sonar that lets them see the flesh, organs and bones of each other and other animals. They are very intelligent animals with a natural inclination to helpfulness and co-operation. Both the military and the entertainment industry have tapped into their innate nature much to both industry's benefit. Dogs are used for medical reasons, the classic being guide dogs, but also for cancer detection or blood glucose alarms for diabetics.
If you trained a dolphin (or more) for diagnostic purposes it could help with mystery conditions. You could put the patient in the water with the dolphin and let the animals swim around them scanning the patient. They could tap the patient gently where the problem is "seen". If it is not a localised problem, there could be coloured boards to tap that indicate different aspects, such as "blood", "hot/cold", etc. It would be a cheaper and less dangerous system then x-rays, blood tests, or cat scans. Alternative therapies would be interested, and some medical doctors who are open minded yet have a patient with a chronic complaint that has no easily found answer could very well benefit.