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Equine asthma (EA) is an important cause of wastage in the USA horse industry. Exposure to organic particulates, from stable dust, airborne pollen, and fungal loads, is posited to be the main cause. Dust arising from the earth's crust has been largely ignored as a contributor to EA in the veterinary literature. The objectives of this study were to investigate the occurrence of birefringent particulates in the bronchoalveolar lavage fluid (BALF) of horses with a clinical complaint of EA residing in the arid West of the USA v. the East, in an effort to determine the contribution of geolocation to geogenic dust exposure. We analyzed BALF cytology and historical data sent to our referral clinical laboratory from 148 horses from the West Coast and 233 horses from the East Coast of the USA over a 6-year period, using light microscopy to determine cell proportions and other visible elements as well as a polarizing lens to detect birefringent material. Univariate analysis showed that horses from the West coast were significantly more likely to have birefringent particulates in the BALF than horses from the East coast (40.5% v. 8.6%, p < 0.001); while horses from the East had higher BALF neutrophil proportions. Horses from the West also had lower proportions of neutrophils in the BALF than those from the East (27.1 v. 10.9, p <.001). Using historical and BAL data in a forward stepwise binary logistic regression model with presence of birefringent particulates found within alveolar macrophages as the outcome, geographical location in the West retained significance as a predictor (OR 8.0, CI [4.3–14.8], p<.001). While the birefringent particulates cannot be identified on the basis of polarizing microscopy alone, this study provides evidence that horses from the West are exposed to inorganic particulates that may contribute to signs of equine asthma. [ABSTRACT FROM AUTHOR]

BackgroundInflammatory airway disease (IAD) in horses, similar to asthma in humans, is a common cause of chronic poor respiratory health and exercise intolerance due to airway inflammation and exaggerated airway constrictive responses. Human rhinovirus is an important trigger for the development of asthma; a similar role for viral respiratory disease in equine IAD has not been established yet.MethodsIn a case-control study, horses with IAD (n = 24) were compared to control animals from comparable stabling environments (n = 14). Horses were classified using pulmonary function testing and bronchoalveolar lavage. PCR for equine rhinitis virus A and B (ERAV, ERBV), influenza virus (EIV), and herpesviruses 2, 4, and 5 (EHV-2, EHV-4, EHV-5) was performed on nasal swab, buffy coat from whole blood, and cells from BAL fluid (BALF), and serology were performed. Categorical variables were compared between IAD and control using Fisher's exact test; continuous variables were compared with an independent t-test. For all analyses, a value of P

Copyright of Canadian Journal of Veterinary Research / Revue Canadienne de Recherche Vétérinaire is the property of Canadian Veterinary Medical Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Background Adult mice have a remarkable capacity to regenerate functional alveoli following either lung resection or injury that exceeds the regenerative capacity observed in larger adult mammals. The molecular basis for this unique capability in mice is largely unknown. We examined the transcriptomic responses to single lung pneumonectomy in adult mice in order to elucidate prospective molecular signaling mechanisms used in this species during lung regeneration. Methods Unilateral left pneumonectomy or sham thoracotomy was performed under general anesthesia (n = 8 mice per group for each of the four time points). Total RNA was isolated from the remaining lung tissue at four time points post-surgery (6 hours, 1 day, 3 days, 7 days) and analyzed using microarray technology. Results The observed transcriptomic patterns revealed mesenchymal cell signaling, including up-regulation of genes previously associated with activated fibroblasts (Tnfrsf12a, Tnc, Eln, Col3A1), as well as modulation of Igf1-mediated signaling. The data set also revealed early down-regulation of pro-inflammatory cytokine transcripts and up-regulation of genes involved in T cell development/function, but few similarities to transcriptomic patterns observed during embryonic or post-natal lung development. Immunohistochemical analysis suggests that early fibroblast but not myofibroblast proliferation is important during lung regeneration and may explain the preponderance of mesenchymal-associated genes that are over-expressed in this model. This again appears to differ from embryonic alveologenesis. Conclusion These data suggest that modulation of mesenchymal cell transcriptome patterns and proliferation of S100A4 positive mesenchymal cells, as well as modulation of pro-inflammatory transcriptome patterns, are important during post-pneumonectomy lung regeneration in adult mice.

Copyright of Canadian Journal of Veterinary Research / Revue Canadienne de Recherche Vétérinaire is the property of Canadian Veterinary Medical Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective--To validate the use of noninvasive pulmonary function testing in sedated and nonsedated llamas and establish reference range parameters of respiratory mechanical function. Animals--10 healthy adult llamas. Procedures--Pulmonary function testing in llamas included the following: measurement of functional residual capacity (FRC) via helium dilution, respiratory inductance plethysmography (RIP) to assess breathing pattern and flow limitations, esophageal-balloon pneumotachography, and a monofrequency forced oscillatory technique (FOT; 1 to 7 Hz) before and after IM administration of xylazine (0.2 mg/kg). Results--The following mean ± SD measurements of respiratory function were obtained in nonsedated llamas: FRC (5.60 ± 1.24 L), tidal volume (1.03 ± 0.3 L), dynamic compliance (0.83 ± 0.4 L/cm H2O), pulmonary resistance (RL; 1.42 ± 0.54 cm H2O/L/s), and respiratory system resistance (2.4 ± 0.9, 2.3 ± 0.7, 2.2 ± 0.6, 2.7 ± 0.7, and 2.5 ± 0.5 cm H2O/L/s at 1, 2, 3, 5, and 7 Hz, respectively) by use of FOT. Measurements of flow limitations via RIP were comparable to other species. Sedation with xylazine induced significant increases in RL and maximum change in transpulmonary pressure. Following sedation, a mean 127% increase in RL and mean 116% increase in respiratory system resistance were observed across 1 to 7 Hz. The magnitude of change in respiratory system resistance increased with decreasing impulse frequency, suggesting bronchoconstriction. Conclusions and Clinical Relevance--Noninvasive pulmonary function testing is well tolerated in untrained unsedated llamas. These techniques have clinical applications in the diagnosis and treatment of respiratory tract disease, although testing should not be performed after sedation with xylazine. [ABSTRACT FROM AUTHOR]

Pulmonary function testing is critical to the diagnosis of equine asthma (EA), an important cause of respiratory disease in the horse, but its clinical use has remained elusive, unfortunately, due to the complexity of reference methods, esophageal balloon/pneumotachography (EBP) and forced oscillatory mechanics (FOM), so we sought a non-invasive, portable method for use in horses through rapid interruption of airflow for equilibration of alveolar pressure with proximal airway pressure, termed flow interruption (FI). Resistance (R INT ) was computed as the relationship between the change in pressure at the nose before and immediately after interruption and flow immediately before interruption. A pilot study in 5 healthy university-owned animals using EBP and FI showed good correspondence between the two methods: R INT (0.33 +/- 0.05 cm H 2 O/l/s) and R L (0.31 +/- 0.06 cm H 2 O/l/s). In 2 separate populations of client-owned horses, with random assignment of methods to FI v EBP (n = 8), R INT showed good correlation with R L in horses, ( r s =.995, p = .0002) and accords with R L , with no significant difference between R INT and R L . Using FOM (n = 12), R INT (0.67 +/- 0.31 cmH 2 O/l/s) has good correlation with R RS measured with FOM ( r =.834, p = .0001), but is consistently smaller than R RS (0.74 +/- 0.33 cmH 2 O/l/s) . Histamine bronchoprovocation (HBP) was performed in a subset of these horses: FI classified one horse in 6 as less reactive than did EBP, and FI classified one horse in 7 as less reactive than did FOM.