title: Efficacy of gamithromycin for the treatment of foals with mild to moderate bronchopneumonia.
abstract: BACKGROUND
  Gamithromycin is active in vitro against the bacterial agents most commonly associated with bronchopneumonia in older foals. However, the clinical efficacy and safety of this drug have not been investigated.
  
  
  OBJECTIVE
  Gamithromycin is effective for the treatment of bronchopneumonia in foals.
  
  
  METHODS
  One hundred and twenty-one foals on a farm endemic for infections caused by Rhodococcus equi.
  
  
  METHODS
  In a controlled, randomized, and double blinded clinical trial, foals with ultrasonographic evidence of pulmonary abscesses (abscess score 8.0-20 cm) were randomly allocated in 3 treatment groups: (1) gamithromycin IM q7 days (n = 40); (2) azithromycin with rifampin, PO q24h (n = 40); or (3) no antimicrobial treatment (controls; n = 41). Physical examination and thoracic ultrasonography were performed by individuals unaware of treatment group assignment. Foals that worsened were removed from the study.
  
  
  RESULTS
  The proportion of foals that recovered without the need to be removed from the study was significantly higher for foals treated with gamithromycin (38 of 40) or azithromycin with rifampin (39 of 40) than for controls (32 of 41). Treatment with gamithromycin or with azithromycin-rifampin resulted in a significantly faster decrease in the clinical score and abscess score compared to the controls. Adverse reactions characterized by colic (n = 18) and hind limb lameness (n = 14) were observed only in foals treated with gamithromycin.
  
  
  CONCLUSIONS
  Gamithromycin was noninferior to azithromycin with rifampin for the treatment of bronchopneumonia in the study population but had a higher frequency of adverse reactions.
authors.affiliation: Equine Clinic, School of Veterinary Medicine, Hanover, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Hildebrand
authors.forename: M
authors.initials: M
authors.lastname: Venner
authors.forename: S
authors.initials: S
authors.lastname: Giguère
mesh_terms: D000038:Abscess / Q000382:microbiology / Q000662:veterinary; D000193:Actinomycetales Infections / Q000662:veterinary*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D017963:Azithromycin / Q000008:administration & dosage / Q000627:therapeutic use; D001996:Bronchopneumonia / Q000188:drug therapy / Q000662:veterinary*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D006734:Horse Diseases / Q000188:drug therapy / Q000382:microbiology*; D006736:Horses; D018942:Macrolides / Q000627:therapeutic use*; D008297:Male; D016929:Rhodococcus equi; D012293:Rifampin / Q000008:administration & dosage / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; D017963:Azithromycin; D012293:Rifampin; C552399:gamithromycin
keywords: Macrolide; Pneumonia; Rhodococcus equi