title: Randomized, non-inferiority trial comparing a nitric oxide releasing solution with a macrolide antibiotic for control of bovine respiratory disease in beef feedlot calves at high-risk of developing respiratory tract disease.
abstract: Nitric oxide, a molecule produced in most mammalian cells, has bactericidal and virucidal properties. Nasal instillation of a nitric oxide releasing solution (NORS) on arrival at the feedlot was recently reported as non-inferior to a parenteral injection of a macrolide antibiotic, tilmicosin, for control of bovine respiratory disease (BRD) in cattle at low-to-moderate risk of developing BRD. The objective of this study was to evaluate whether NORS was non-inferior to tilmicosin for control of BRD in cattle at high-risk of developing BRD (the target population for many BRD control programs). High-risk Angus-cross heifers (n=840) were randomly allocated to 2 treatment groups on arrival at a feedlot and received either NORS or tilmicosin for BRD control. Non-inferiority was assessed by calculating the difference in prevalence of heifers diagnosed with BRD during the first 40 d after arrival between NORS and tilmicosin treatment groups. The non-inferiority margin (δ) was set at 8.5%. Thirty-six and 19% of heifers were diagnosed with BRD in the NORS and tilmicosin groups, respectively. Because the lower bound of the 2-sided 95% confidence interval (CI) of the difference in BRD prevalence between the 2 treatment groups (17%; 95% CI=11-23%) was higher than δ, an inferiority of NORS was concluded. Although on-arrival nasal administration of NORS can be viewed as a more rational control strategy than parental injection of antibiotics, further research is needed to improve NORS efficacy before it can be recommended to prevent BRD in high-risk cattle.
authors.affiliation: Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Crepieux
authors.affiliation: Faculty of Medicine, Respiratory Division, University of British Columbia, Vancouver, BC, Canada; Bovicor Pharmatech Inc., Vancouver, BC, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Miller
authors.affiliation: Faculty of Medicine, Respiratory Division, University of British Columbia, Vancouver, BC, Canada; Bovicor Pharmatech Inc., Vancouver, BC, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Regev-Shoshani
authors.affiliation: Department of Agricultural, Food and Nutritional Science (AFNS), University of Alberta, Edmonton, AB, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Schaefer
authors.affiliation: Veterinary Agri-Health Services, Airdrie, AB, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Dorin
authors.affiliation: Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, AB, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Alexander
authors.affiliation: Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada. Electronic address: eftimsit@ucalgary.ca.
authors.forename: E
authors.initials: E
authors.lastname: Timsit
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D048090:Bovine Respiratory Disease Complex / Q000209:etiology / Q000517:prevention & control*; D002417:Cattle; D005260:Female; D009569:Nitric Oxide / Q000008:administration & dosage / Q000627:therapeutic use*; D015995:Prevalence; D015645:Tylosin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D009569:Nitric Oxide; C052319:tilmicosin; D015645:Tylosin
keywords: Alternative to antibiotics; BRD; Metaphylaxis; Prevention; Tilmicosin