In any consideration of the diseases of marine mammals and their treatment, the physiological adjustments that these animals have made to the aquatic environment are quite important. The flexible cetacean rib cage that is essential to the animal for deep diving is a detriment when the animal must be transported out of the water. This factor should be considered in the design of transport containers. Serious thermoregulatory problems may be produced by barbiturates and tranquilizers. The clinician who administers these must be prepared to control body temperature. Dietary carbohydrate is almost completely lacking in dolphins and most other marine mammals. Glucose metabolism and liver physiology have adjusted to this protein-fat diet. Some ramifications of this situation are being uncovered in drug therapy, anesthesia and disease conditions.