Nedocromil Sodium Inhibits Canine Adenovirus Bronchiolitis in Beagle Puppies

Abstract

Nedocromil sodium is a nonsteroidal anti-inflammatory drug used to control asthmatic attacks. Our hypothesis is that nedocromil sodium inhibits virus-induced airway inflammation, a common trigger of asthma. We nebulized nedocromil sodium into beagle dogs (n = 10, mean ± SEM ages: 149 ± 13 days) before and after inoculation with canine adenovirus type 2 (CAV2). Control dogs (n = 10) received saline aerosols and were either infected with CAV2 (Sa1/CAV2, n = 7, mean ± SEM ages: 140 ± 11 days) or were not infected (Sal/Sal, n = 3, ages: 143 ± 0 days). All dogs were anesthetized with choralose (80 mg/kg IV), intubated, and mechanically ventilated. Pulmonary function tests and bronchoalveolar lavage (BAL) were performed using standard techniques. Pulmonary function tests revealed no significant change between the nedocromil sodium and non-nedocromil-treated groups. The percentage of infected bronchioles was quantitated as the number of inflamed airways of 40 bronchioles examined times 100 for each dog. Nedocromil-treated dogs had significantly (p < 0.05) less mucosal inflammation (mean ± SEM, 39% ± 5%), epithelial denudation (36% ± 5%), and BAL neutrophilia (11 ± 3) than did Sal/CAV2 dogs (51% ± 6%, 57% ± 4%, and 33% ± 8%, respectively). We concluded that pretreatment with nedocromil sodium aerosols attenuated CAV2-induced airway inflammation in these beagle puppies.