Collection of exhaled breath and exhaled breath condensate in veterinary medicine. A review

Bovine Respiratory Syncytial Virus (BRSV) Infection Detected in Exhaled Breath Condensate of Dairy Calves by Near-Infrared Aquaphotomics

Bovine respiratory syncytial virus (BRSV) is a major contributor to respiratory disease in cattle worldwide. Traditionally, BRSV infection is detected based on non-specific clinical signs, followed by reverse transcriptase-polymerase chain reaction (RT-PCR), the results of which can take days to obtain. Near-infrared aquaphotomics evaluation based on biochemical information from biofluids has the potential to support the rapid identification of BRSV infection in the field. This study evaluated NIR spectra (n = 240) of exhaled breath condensate (EBC) from dairy calves (n = 5) undergoing a controlled infection with BRSV. Changes in the organization of the aqueous phase of EBC during the baseline (pre-infection) and infected (post-infection and clinically abnormal) stages were found in the WAMACS (water matrix coordinates) C1, C5, C9, and C11, likely associated with volatile and non-volatile compounds in EBC. The discrimination of these chemical profiles by PCA-LDA models differentiated samples collected during the baseline and infected stages with an accuracy, sensitivity, and specificity >93% in both the calibration and validation. Thus, biochemical changes occurring during BRSV infection can be detected and evaluated with NIR-aquaphotomics in EBC. These findings form the foundation for developing an innovative, non-invasive, and in-field diagnostic tool to identify BRSV infection in cattle.

Collection and analysis of breath and breath condensate exhaled by feral pigeons (Columba livia) and chickens (Gallus domesticus)

Samples of exhaled breath and breath condensate were collected from 20 feral pigeons (Columba livia) while they were anaesthetised and intubated, and when they were kept unanaesthetised in an acrylic box. Samples were also collected from six chickens (Gallus domesticus) while they were kept in an acrylic box. The samples were analysed for pH, nitric oxide (NO), hydrogen peroxide and leukotriene B4. The volume of condensate collected from the pigeons was independent of bodyweight and significantly more (1.66 [0.64] ml/kg) was obtained while they were in the acrylic box than when they were intubated (0.87 [0.32] ml/kg). The mean volume collected from the chickens was 0.15 (0.06) ml/kg. Cooled samples had higher concentrations of NO than uncooled samples. The pH of the samples of condensate collected from birds in the acrylic box were significantly higher (7.9 [0.3]) than those from the intubated birds (5.3 [0.1]), and samples from the chickens had significantly higher pH values than samples from the pigeons (8.2 [0.2] v 7.9 [0.3]).