One of the more subjective areas of preventative medicine is the determination of optimal planes of nutrition for individual animals. There are numerous ways to ascertain if the diet is meeting the metabolic requirements of the animal, for example, body condition, weight, growth levels or appetite. Many serum biochemical tests have been used as well, total protein, albumin, calcium, phosphorus, uric acid, glucose, total iron binding capacity, and possibly triglyceride or cholesterol levels. We have found in the case of growing cetaceans, alkaline phosphatase levels may indicate a trend of catabolic versus anabolic states.

Serum levels of alkaline phosphatase are actually composed of a group of isoenzymes that have a variety of sources. In cetaceans the sources and relative amounts of the various isoenzymes have not been reported yet, however, it is known that growing mammals have a significant level of alkaline phosphatase that is of bone origin. We have seen in several different species of cetaceans a relationship between weight gain or loss and a corresponding increase or decrease in serum alkaline phosphatase levels. These changes seem to be more sensitive than other biochemical changes and can provide an objective number which may indicate if the level of nutrition is adequate for bone deposition and therefore growth of the animal.

There are limitations to using alkaline phosphatase to evaluate nutritional status. Circulating levels will drop in ill cetaceans and are often used as a prognostic indicator. Increased age and maturity level of animals can dramatically lower the values of this serum enzyme while other physiological events may affect it as well. If you can routinely monitor the hematological and biochemical parameters of individual animals, make allowances for potential signs of infection, and observe trends rather than absolute values, alkaline phosphatase may prove to be a reliable indicator of the metabolic state of cetaceans.