Gallium maltolate as an alternative to macrolides for treatment of presumed Rhodococcus equi pneumonia in foals. Academic Article uri icon


  • BACKGROUND: Macrolide-resistant isolates of Rhodococcus equi are emerging, prompting the search for clinically effective alternative antimicrobials. HYPOTHESIS: The proportion of foals with ultrasonographic evidence of pneumonia presumed to be caused by R. equi that had a successful outcome when administered gallium maltolate (GaM) PO would not be more than 10% inferior (ie, lower) than that of foals receiving standard treatment. ANIMALS: Fifty-four foals with subclinical pulmonary abscesses among 509 foals at 6 breeding farms in Kentucky. METHODS: Controlled, randomized, prospective noninferiority study. Foals with ultrasonographic lesions >1 cm in diameter (n = 54) were randomly allocated to receive per os either clarithromycin combined with rifampin (CLR+R) or GaM, and followed up for 28 days by daily physical inspections and weekly (n = 1 farm) or biweekly (n = 4 farms) thoracic ultrasound examinations by individuals unaware of treatment-group assignments. Treatment success was defined as resolution of ultrasonographically identified pulmonary abscesses within 28 days of initiating treatment. Noninferiority was defined as a 90% confidence interval for the observed difference in CLR+R minus GaM that was 10%. RESULTS: The proportion of GaM-treated foals that resolved (70%; 14/20) was similar to that of foals treated with CLR+R (74%; 25/34), but we failed to demonstrate noninferiority for GaM relative to CLR+R; however, GaM was noninferior to CLR+R treatment when results from a noncompliant farm were excluded. CONCLUSIONS AND CLINICAL IMPORTANCE: Gallium maltolate is not inferior to macrolides for treating foals with subclinical pneumonia. Use of GaM might reduce pressure for macrolide-resistance in R. equi.

published proceedings

  • J Vet Intern Med

altmetric score

  • 0.25

author list (cited authors)

  • Cohen, N. D., Slovis, N. M., Gigure, S., Baker, S., Chaffin, M. K., & Bernstein, L. R.

citation count

  • 18

complete list of authors

  • Cohen, Noah D||Slovis, Nathan M||Giguère, Steeve||Baker, Samantha||Chaffin, M Keith||Bernstein, Lawrence R

publication date

  • April 2015