The anti-inflammatory effects of IV administered clenbuterol in horses with recurrent airway obstruction.

Cyclic AMP elevating agents have been shown to exhibit anti-inflammatory properties in addition to functions such as bronchodilation. The aim of this study was to investigate this dual action of clenbuterol (CB; Ventipulmin) on horses affected with recurrent airway obstruction (RAO). Seven RAO susceptible horses received inhalation challenges with aerosolised lipopolysaccharide (LPS), hay dust suspension (HDS) and Aspergillus fumigatus antigen (AF) with and without prior treatment with intravenous CB.

The role of alveolar macrophages in the pathogenesis of recurrent airway obstruction in horses.

When challenged with allergens and pro-inflammatory agents, such as Aspergillus fumigatus (AF), hay dust solution (HDS) and lipopolysaccharide (LPS), the innate immune response will not only activate the immune system but also increase the amount of pro-inflammatory cytokines in the bronchoalveolar space. The aim of this study was to assess the response of equine alveolar macrophages to different aerosolized challenges and to investigate the differences in this response between horses susceptible or nonsusceptible to recurrent airway obstruction (RAO). Seven susceptible and 5 nonsusceptible horses were challenged with saline, LPS, HDS, or AF, and bronchoalveolar lavage (BAL) cytology, total cell counts, and lung function were assessed.

Evaluation of cytokine production by equine alveolar macrophages exposed to lipopolysaccharide, Aspergillus fumigatus, and a suspension of hay dust.

Objective: To evaluate cytokine production by equine alveolar macrophages after exposure to lipopolysaccharide (LPS), Aspergillus fumigatus, and hay dust, and determine the effect of clenbuterol on the cytokine response.

Animals: 6 horses.

Procedure: Alveolar macrophages were exposed to PBS solution (negative control), LPS, hyphae and conidia of Aspergillus fumigatus (AF), or a suspension of hay dust (HDS) and incubated for 24 hours at 37 degrees C.

Effects of antitussive agents administered before bronchoalveolar lavage in horses.

Objective: To determine whether treatment of horses with antitussive agents before bronchoalveolar lavage (BAL) reduces the frequency and intensity of the cough reflex during BAL.

Animals: 8 healthy horses.

Procedure: Standard BAL was performed on each horse weekly for 6 weeks.