title: Investigation of Neurokinin-1 Receptor Antagonism as a Novel Treatment for Chronic Bronchitis in Dogs.
abstract: BACKGROUND
  Canine chronic bronchitis (CCB) results in cough lasting ≥2 months and airway inflammation. Adverse effects include risk of secondary infection associated with lifelong corticosteroid administration and prompt investigation into alternative therapies. Neurogenic pathways mediated by tachykinins that bind neurokinin (NK) 1 receptors may induce cough and airway inflammation. Maropitant, a NK-1 receptor antagonist, has been advocated for treatment of CCB based on anecdotal improvement, but without scientific evidence.
  
  
  OBJECTIVE
  Maropitant will blunt clinical signs and airway inflammation associated with CCB.
  
  
  METHODS
  Client-owned dogs (n = 8) with cough >2 months, thoracic radiographic evidence of airway disease and sterile airway inflammation (>7% non-degenerate neutrophils, >7% eosinophils or both) on bronchoalveolar lavage (BAL) enrolled.
  
  
  METHODS
  Maropitant (2 mg/kg) administered q48h for 14 days. Study endpoints included client perception of clinical signs (surveys at baseline and 14 days, and visual analogue scale [VAS] at baseline, 7, and 14 days), and BAL % neutrophils and eosinophils (baseline and 14 days). One-way repeated measures ANOVA (VAS) and Wilcoxon-signed rank-sum tests (BAL cells, cough frequency) used with P < .05 considered significant.
  
  
  RESULTS
  Maropitant significantly decreased cough frequency (P < .001) and VAS scores (P = .005). No differences in BAL % neutrophils or % eosinophils noted with treatment (P = .279 and P = .382, respectively).
  
  
  CONCLUSIONS
  Preliminary results suggest that although maropitant may have antitussive properties leading to perceived clinical improvement, its failure to diminish airway inflammation makes it unsuitable for treatment of CCB. Future studies could evaluate maropitant as a cough suppressant for other respiratory disorders in dogs.
authors.affiliation: Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO.
authors.forename: M
authors.initials: M
authors.lastname: Grobman
authors.affiliation: Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO.
authors.forename: C
authors.initials: C
authors.lastname: Reinero
mesh_terms: D000818:Animals; D029481:Bronchitis, Chronic / Q000188:drug therapy / Q000473:pathology / Q000662:veterinary*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D003371:Cough / Q000188:drug therapy / Q000473:pathology / Q000662:veterinary; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D004804:Eosinophils / Q000187:drug effects / Q000473:pathology; D005260:Female; D008297:Male; D064729:Neurokinin-1 Receptor Antagonists / Q000008:administration & dosage / Q000627:therapeutic use*; D009504:Neutrophils / Q000187:drug effects / Q000473:pathology; D011812:Quinuclidines / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D064729:Neurokinin-1 Receptor Antagonists; D011812:Quinuclidines; C518176:maropitant
keywords: Cough; Maropitant; TRPV1; Tachykinin