Cancer evaluation in dogs using cerumen as a source for volatile biomarker prospection.

Cancer is one of the deadliest diseases in humans and dogs. Nevertheless, most tumor types spread faster in canines, and early cancer detection methods are necessary to enhance animal survival. Here, cerumen (earwax) was tested as a source of potential biomarkers for cancer evaluation in dogs. Earwax samples from dogs were collected from tumor-bearing and clinically healthy dogs, followed by Headspace/Gas Chromatography-Mass Spectrometry (HS/GC-MS) analyses and multivariate statistical workflow. An evolutionary-based multivariate algorithm selected 18 out of 128 volatile metabolites as a potential cancer biomarker panel in dogs. The candidate biomarkers showed a full discrimination pattern between tumor-bearing dogs and cancer-free canines with high accuracy in the test dataset: an accuracy of 95.0% (75.1-99.9), and sensitivity and specificity of 100.0% and 92.9%, respectively. In summary, this work raises a new perspective on cancer diagnosis in dogs, being carried out painlessly and non-invasive, facilitating sample collection and periodic application in a veterinary routine.

Identification of cattle poisoning by Bifenthrin via earwax analysis by HS/GC-MS.

The use of pyrethroids has increased over recent years, and corresponds to a higher exposure of animals to pesticide residues in the environment and diet. Here, an outbreak of pyrethroid poisoning in beef cattle was reported occurring in Midwestern Brazil. After veterinary evaluation, it was observed that the bovines presented common pyrethroid intoxication symptoms. Aiming to identify the cattle poising by pyrethroid, earwax samples were collected from two groups: exposed and nonexposed animals from the same farm. Blind earwax analyses of the bovines were carried out using headspace/gas chromatography-mass spectrometry (HS/GC-MS). The HS/GC-MS analysis detected the presence of bifenthrin in the earwax analysis of the exposed animals, confirmed by the comparison of its MS fragments with a bifenthrin standard, and also by its retention time relative to the internal standard. In summary, HS/GC-MS analysis of earwax emerges as a tool that can be used in the detection and monitoring of bifenthrin poisoning in cattle, as a useful veterinary diagnosis that ensures animal health and the safety of their products.