Efficacy of azithromycin in preventing pulmonary abscesses in foals.
Abstract: The prophylactic application of azithromycin to prevent pulmonary abscesses in foals was evaluated on a stud with endemic Rhodococcus equi pneumonia. Forty-five foals served as untreated controls in two groups. Twenty-five foals were given azithromycin (10mg/kg) orally once daily for 4 weeks. The foals were examined once a week from birth to the age of 5 months. If clinical signs or leucocytosis were noted and pulmonary sonographic findings (diameter >10 mm) were observed, the diagnosis of abscessing pneumonia was made. The prevalence of pulmonary abscesses was similar in the control groups (31/45 foals), and in the azithromycin group (15/25 foals), but the foals in the azithromycin group were affected significantly later (median: day 83, range 67-123 days) (control groups: day 54, range 52-82; and 46, range 28-86 days). It was concluded that the application of azithromycin for 28 days post-natally does not reduce the prevalence of pulmonary abscesses in foals on a stud with endemic pneumonia.
Publication Date: 2007-11-26 PubMed ID: 18023599DOI: 10.1016/j.tvjl.2007.10.002Google Scholar: Lookup
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- Journal Article
Summary
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The research paper examines the preventative use of azithromycin to combat lung abscesses in foals on a stud farm where Rhodococcus equi pneumonia is prevalent. Despite administering azithromycin, the prevalence of lung abscesses was similar in treated and untreated foals, but the onset in treated foals occurred later.
Research Methodology
- The study was conducted on a horse stud with a high incidence of Rhodococcus equi pneumonia.
- A total of 70 foals were used in this study, with 45 serving as untreated controls split into two groups.
- The remaining 25 foals received azithromycin, dosed at 10mg/kg, orally once daily for a period of 4 weeks.
- Weekly exams were conducted on the foals from birth up to the age of 5 months.
- Pulmonary abscesses were diagnosed based on clinical symptoms, leucocytosis (white blood cell count), and pulmonary sonographic findings with a diameter of above 10mm.
Research Findings
- The rate of pulmonary abscesses was comparable in the control groups (31 out of 45 foals) and the azithromycin-treated group (15 out of 25 foals).
- However, foals receiving azithromycin presented with pulmonary abscesses significantly later – at a median of day 83 (range: 67-123 days). This is considerably later than the control groups who developed symptoms at a median of day 54 and day 46 respectively.
Conclusions
- The researchers concluded that administering azithromycin for 28 days after birth does not reduce the prevalence of pulmonary abscesses in foals at a stud with a high incidence of pneumonia.
- This indicates that while azithromycin doesn’t prevent the onset of pulmonary abscesses, it may delay their occurrence.
Cite This Article
APA
Venner M, Reinhold B, Beyerbach M, Feige K.
(2007).
Efficacy of azithromycin in preventing pulmonary abscesses in foals.
Vet J, 179(2), 301-303.
https://doi.org/10.1016/j.tvjl.2007.10.002 Publication
Researcher Affiliations
- University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, D-30173 Hannover, Germany. monica.venner@tiho-hannover.de
MeSH Terms
- Animals
- Animals, Newborn
- Anti-Bacterial Agents / therapeutic use
- Azithromycin / therapeutic use
- Female
- Horse Diseases / prevention & control
- Horses
- Lung Abscess / prevention & control
- Lung Abscess / veterinary
- Male
- Pneumonia, Bacterial / prevention & control
- Pneumonia, Bacterial / veterinary
- Random Allocation
- Treatment Outcome
Citations
This article has been cited 12 times.- Berghaus LJ, Venner M, Helbig H, Hildebrandt D, Hart K. The potential value of cytokine, cortisol and vitamin D profiles in foals from birth to weaning for respiratory disease prediction on a farm endemic for Rhodococcus equi pneumonia. Equine Vet J 2026 Mar;58(2):359-371.
- Baptiste KE, Kyvsgaard NC, Ahmed MO, Damborg P, Dowling PM. Is Rifampin (Rifampicin) Essential for the Treatment of Rhodococcus equi Infections in Foals? A Critical Review of the Role of Rifampin. J Vet Pharmacol Ther 2025 Sep;48(5):345-358.
- Kahn SK, Cywes-Bentley C, Blodgett GP, Canaday NM, Turner-Garcia CE, Flores-Ahlschwede P, Metcalfe LL, Nevill M, Vinacur M, Sutter PJ, Meyer SC, Bordin AI, Pier GB, Cohen ND. Randomized, controlled trial comparing Rhodococcus equi and poly-N-acetyl glucosamine hyperimmune plasma to prevent R equi pneumonia in foals. J Vet Intern Med 2021 Nov;35(6):2912-2919.
- Vail KJ, da Silveira BP, Bell SL, Cohen ND, Bordin AI, Patrick KL, Watson RO. The opportunistic intracellular bacterial pathogen Rhodococcus equi elicits type I interferon by engaging cytosolic DNA sensing in macrophages. PLoS Pathog 2021 Sep;17(9):e1009888.
- Kahn SK, Cywes-Bentley C, Blodgett GP, Canaday NM, Turner-Garcia CE, Vinacur M, Cortez-Ramirez SC, Sutter PJ, Meyer SC, Bordin AI, Vlock DR, Pier GB, Cohen ND. Antibody activities in hyperimmune plasma against the Rhodococcus equi virulence -associated protein A or poly-N-acetyl glucosamine are associated with protection of foals against rhodococcal pneumonia. PLoS One 2021;16(8):e0250133.
- Cohen ND, Kahn SK, Cywes-Bentley C, Ramirez-Cortez S, Schuckert AE, Vinacur M, Bordin AI, Pier GB. Serum Antibody Activity against Poly-N-Acetyl Glucosamine (PNAG), but Not PNAG Vaccination Status, Is Associated with Protecting Newborn Foals against Intrabronchial Infection with Rhodococcus equi. Microbiol Spectr 2021 Sep 3;9(1):e0063821.
- Rakowska A, Cywinska A, Witkowski L. Current Trends in Understanding and Managing Equine Rhodococcosis. Animals (Basel) 2020 Oct 18;10(10).
- Huber L, Giguère S, Slovis NM, Carter CN, Barr BS, Cohen ND, Elam J, Erol E, Locke SJ, Phillips ED, Smith JL. Emergence of Resistance to Macrolides and Rifampin in Clinical Isolates of Rhodococcus equi from Foals in Central Kentucky, 1995 to 2017. Antimicrob Agents Chemother 2019 Jan;63(1).
- Rutenberg D, Venner M, Giguère S. Efficacy of Tulathromycin for the Treatment of Foals with Mild to Moderate Bronchopneumonia. J Vet Intern Med 2017 May;31(3):901-906.
- McQueen CM, Whitfield-Cargile CM, Konganti K, Blodgett GP, Dindot SV, Cohen ND. TRPM2 SNP genotype previously associated with susceptibility to Rhodococcus equi pneumonia in Quarter Horse foals displays differential gene expression identified using RNA-Seq. BMC Genomics 2016 Dec 5;17(1):993.
- McQueen CM, Dindot SV, Foster MJ, Cohen ND. Genetic Susceptibility to Rhodococcus equi. J Vet Intern Med 2015 Nov-Dec;29(6):1648-59.
- Hildebrand F, Venner M, Giguère S. Efficacy of gamithromycin for the treatment of foals with mild to moderate bronchopneumonia. J Vet Intern Med 2015 Jan;29(1):333-8.
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