This Dolphin Breathalyzer Hopes to Find Disease, Not Booze

Non-invasively screening for cancers and other diseases by measuring the chemical profiles of peoples' breath is a burgeoning area of research. Scientists at the University of California, Davis, have figured how to do the same with bottlenose dolphins.

After capturing the breath of dolphins in managed populations and in the wild, the researchers used gas chromatography to parse the chemical makeup of their pulmonary expulsions. By establishing a baseline metabolite composition for the breath of the different dolphin populations, the researchers were able to measure deviations from the norm that might indicate the presence of illnesses.

"When wild animal populations are stressed or there are infectious disease outbreaks, it is helpful to know this quickly," Cristina E. Davis, one of the researchers, told me over email. "We would like to be able to help diagnose dolphin respiratory infections, which would be very helpful."

Using electronic noses—devices that mimic the function of biological olfactory systems—to analyze human breath is a tricky science, due to our nasal cavities and mouths being connected. This leads to contamination by odors from the digestive system, as a garlicky pasta dinner can mask the presence of metabolites that might indicate illness.

Dolphins, on the other hand, are more biologically suited to breath analysis, according to the UC Davis researchers' paper, which was published in the American Chemical Society journal Analytical Chemistry.

Dolphins' separated digestive and pulmonary systems make breath analysis more accurate, or at least easier to make sense of, but collecting explosive blasts of air from a blowhole is exactly as tricky as it sounds.

To do so, the team built a specialized device that used a system of one-way valves and sanitized glass tubes chilled with dry ice to minimize ambient air contamination and shock to the animals due to temperature differences in their air intake.

The actual analysis of the animals' breath took place in a lab, but the team has plans to build a small, portable device that can collect and analyze the metabolites of dolphins, much like current electronic noses such as the Cyranose 320, which has been used to detect the presence of cancers in humans.

"My group is currently working on some miniature field portable chemical sensors that can be used to measure metabolites in the field," Davis wrote. "Although we have not used these for dolphins yet, they are potentially very useful tools to measure exhaled metabolites directly from the animals in near-real-time."

Before this can happen, however, more research needs to be done into what smelly dolphin breath has to say about their health. While the researchers were able to detect the presence of various metabolites, it's not clear what, exactly, they correlate to in terms of illnesses. Even so, the team's approach could mean an end to invasive techniques like skin biopsies being used on marine life, as well as faster monitoring of a population's health.