• Open Access

Effect of Long-Term Fluticasone Treatment on Immune Function in Horses with Heaves



This article is corrected by:

  1. Errata: Erratum Volume 26, Issue 2, 444, Article first published online: 20 March 2012

  • An abstract of this work was presented at the 27th Annual ACVIM Forum in Montreal, QC, Canada, June 2009.

Corresponding author: Jean-Pierre Lavoie, Département des Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montréal, 3200 rue Sicotte, Saint-Hyacinthe J2S 7C6, QC, Canada; e-mail: jean-pierre.lavoie@umontreal.ca.


Background: Corticosteroids currently are the most effective pharmacological treatment available to control heaves in horses. Systemically administered corticosteroids have been shown to alter immune response in horses, humans, and other species. Aerosolized administration theoretically minimizes systemic adverse effects, but the effect of inhaled corticosteroids on immune function has not been evaluated in horses.

Objectives: To evaluate the effects of prolonged administration of inhaled fluticasone on the immune system of heaves-affected horses.

Animals: Heaves-affected horses were treated with inhaled fluticasone (n = 5) for 11 months or received environmental modifications only (n = 5).

Methods: Prospective analysis. Clinical parameters and CBC, lymphocyte subpopulations and function, and circulating neutrophil gene expression were sequentially measured. Primary and anamnestic immune responses also were evaluated by measuring antigen-specific antibodies in response to vaccination with bovine viral antigen and tetanus toxoid, respectively.

Results: No clinical adverse effects were observed and no differences in immune function were detected between treated and untreated horses.

Conclusions and Clinical Importance: The treatment of heaves-affected horses with inhaled fluticasone at therapeutic dosages for 11 months has no significant detectable effect on innate and adaptive (both humoral and cell-mediated) immune parameters studied. These results suggest that prolonged administration of fluticasone would not compromise the systemic immune response to pathogens nor vaccination in adult horses.