New review maps the clinical future of olfaction-based diagnostics
Bottom line
Olfaction-based diagnostics are getting a fresh look in a new Talanta review that argues smell, long sidelined in modern medicine, deserves renewed attention as a practical tool for detecting disease-related volatile organic compounds, or VOCs. The paper, published in July 2026, surveys how human olfaction, trained animals, electronic noses, and related breath-analysis systems are being used or explored across infectious disease, metabolic disorders, and cancer detection. It also places the COVID-19 era front and center, noting that the pandemic accelerated interest in rapid, noninvasive smell-based screening and helped move VOC diagnostics closer to clinical relevance. (sciencedirect.com)
Why it matters: For veterinary professionals, the review is a reminder that olfaction is not just a human-medical curiosity. VOC-based diagnostics are already being studied in animals, including cattle, where breath biomarkers have been investigated for conditions such as ketosis and bovine respiratory disease, though researchers say routine use will require more standardized, controlled clinical studies. More broadly, the appeal is clear for veterinary settings: noninvasive sampling, faster turnaround, and potential use in screening or herd-level monitoring. But the same bottlenecks seen in human medicine, including sensor sensitivity, selectivity, environmental interference, and the need for large-scale validation, still stand in the way of day-to-day clinical adoption. (pubmed.ncbi.nlm.nih.gov)
What to watch: Expect the next phase to focus less on proof of concept and more on validation, standardization, and whether VOC platforms can clear regulatory and workflow hurdles in real clinical settings. (accessdata.fda.gov)
Key facts
- Journal
- Talanta
- Publication date
- July 2026
- Article topic
- Olfaction as a diagnostic instrument
- Diagnostic targets
- Infectious disease, metabolic disorders, and cancer detection
- Methods reviewed
- Human olfaction, trained animals, electronic noses, and breath-analysis systems
- Veterinary focus
- Cattle breath biomarkers
- Cattle conditions studied
- Ketosis and bovine respiratory disease
- Main limitation
- Need for standardized, controlled clinical studies
- COVID-19 relevance
- Pandemic accelerated interest in rapid, noninvasive smell-based screening
A new review in Talanta makes the case that olfaction, whether through clinicians, animals, or sensor systems, is re-emerging as a serious diagnostic modality rather than a historical footnote. In “Olfaction as a diagnostic instrument - a review of current, and future medical applications,” the authors argue that disease-linked VOCs can provide clinically useful signals, especially as interest in rapid, noninvasive testing has grown in the wake of COVID-19. (sciencedirect.com)
That argument builds on a long, uneven history. Clinicians once used smell as part of bedside diagnosis, but that practice largely faded as laboratory instrumentation advanced. What changed, according to the broader literature, is not the biology of VOCs but the technology around them: electronic noses, bio-sniffers, and machine-learning tools now offer ways to capture odor signatures more systematically. Recent reviews describe e-noses as attractive because they can be portable, relatively cost-effective, and faster than conventional gas chromatography workflows, even if they still lag those methods in some analytical dimensions. (sciencedirect.com)
The Talanta review arrives at a moment when breath and odor diagnostics have more real-world credibility than they did a decade ago. During the pandemic, the FDA authorized breath-based COVID-19 tests designed to detect VOC patterns associated with SARS-CoV-2 infection, showing that smell-linked diagnostics could move beyond exploratory research and into regulated use cases. FDA classification materials also show that VOC breath-analysis devices now sit within a clearer medical-device framework, even if the pathway remains specialized and evidence-heavy. (fda.gov)
The broader evidence base remains promising but technically messy. Reviews of e-nose and bio-sniffer platforms consistently point to the same strengths, including portability, speed, and noninvasive sampling, while also flagging the same weaknesses: sensor drift, limited selectivity, humidity and temperature effects, and inconsistent sampling and data-processing methods. An editorial perspective published in 2026 in ERJ Open Research put it plainly, arguing that breath analysis has been held back by limited multicenter validation and a lack of standardization robust enough for routine clinical practice. (sciencedirect.com)
For veterinary medicine, that tension between promise and practicality is especially relevant. Animal-health researchers have already reviewed breath VOC biomarkers in cattle disease, with the strongest focus on ketosis and bovine respiratory disease. Those authors concluded that the field is promising, but not yet ready for routine deployment because controlled, standardized studies are still limited. A newer livestock-focused review similarly describes exhalomics as a potential tool for precision monitoring, welfare assessment, and earlier disease detection, while emphasizing the technical difficulty of collecting and interpreting low-concentration VOC signals in real farm environments. (pubmed.ncbi.nlm.nih.gov)
There is also a useful translational angle for companion-animal and production-animal practice. If VOC signatures can be validated across species and conditions, they could support screening in settings where blood draws, imaging, or repeated handling are harder to scale. That could matter for herd surveillance, respiratory disease triage, metabolic monitoring, and potentially even oncology workflows. Still, this is best viewed as an adjunctive frontier, not a replacement for established diagnostics. The regulatory history in human medicine suggests the bar will remain high for analytical validity, clinical validity, and reproducibility before these tools become routine in veterinary clinics or on farms. (accessdata.fda.gov)
Why it matters: For veterinary professionals, the review is less about a single breakthrough than about the direction of travel. Olfaction-based diagnostics align with several pressures already shaping practice, including demand for less invasive testing, faster answers, and scalable monitoring tools. But the field’s next test is operational, not conceptual: whether developers can standardize collection, control environmental noise, train robust algorithms, and generate the kind of multicenter evidence that clinicians and regulators will trust. (sciencedirect.com)
What to watch: Watch for prospective validation studies, species-specific VOC libraries, and early veterinary pilots that move beyond laboratory proof of concept into clinic or farm workflows, because that is where this technology will either become useful or stall. (publications.ersnet.org)