Evaluating bottlenose dolphin health from breath samples
By Bets Rasmussen, PhD, OGI School of Science & Engineering, OHSU

We continued our collection of dolphin breath samples during the 2005 health assessment sessions. Volatile organic compounds in exhaled dolphin breath are a reflection of biochemical constituents circulating in the blood. Non-invasive monitoring of such compounds is beginning to yield health, reproductive, physiological and seasonal information about wild dolphins. From a conservation aspect, information from breath of wild dolphins may reveal (1) areas of localized, specific pollution if particular dolphins are known to frequent such regions, (2) incidence of respiratory diseases, (3) basic metabolic requirements, especially seasonal, and (4) possibly reproductive status information.

During 2005 our data base was extended from 47 dolphins to an additional 7 in February 2005 and 9 in June 2005 making a total of 63 dolphins from whom we have analyzed exhalant breath samples. We continued to identify and now semi-quantitate more than 60 compounds. Several groups of compounds continued to be of particular interest: pentane (indicative of strenuous exercise); several sulfur compounds, presumably of bacterial origin; acids, again perhaps indicative of bacterial infections; aldehydes and isocyanato compounds may also prove to be diagnostic. Our monitoring of concentration changes should increasingly: (1) be indicative of bacterial respiratory problems, or by the inclusion of hydrogen measurements other serious lung problems, (2) reveal seasonal changes related to fat metabolism, as indicated primarily by changes in ketones, and (3) demonstrate chemical clues about reproductive condition. We are occasionally detecting hormone metabolites. We plan a publication on at least one of these aspects in 2006.