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Veterinary microbiology1987; 14(3); 329-336; doi: 10.1016/0378-1135(87)90120-9

Rhodococcus equi pneumonia in 48 foals: response to antimicrobial therapy.

Abstract: Case records of 48 foals with pneumonia due to Rhodococcus equi were reviewed. Twenty of the 48 foals survived and 28 died or were euthanized. There was no significant difference between the survivors and non-survivors in the age of onset of illness, duration of illness prior to admission, the mean white blood cell (WBC) count, or the mean plasma fibrinogen content. All foals had R. equi isolated from a tracheobronchial aspirate or lung specimens obtained at necropsy. All organisms were susceptible in vitro (Kirby-Bauer) to erythromycin and gentamicin. Susceptibilities to other drugs were: trimethoprim-sulfamethoxazole (88%), tetracycline (87%), chloramphenicol (83%); 97% were resistant to cephalothin and 83% to penicillin. Thirteen of the 20 surviving foals were treated with erythromycin and/or rifampin. A decline in mortality rate was observed with the introduction of the combination of erythromycin and rifampin. None of the 17 foals treated with penicillin and gentamicin survived. Chronic, active, non-septic synovitis was confirmed in 17 foals. These foals had joint distension with mild or no apparent lameness.
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Publication Date: 1987-08-01 PubMed ID: 3672875DOI: 10.1016/0378-1135(87)90120-9Google Scholar: Lookup
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  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This study reviews the medical records of 48 foals suffering from Rhodococcus equi pneumonia and their response to antimicrobial therapy. The researchers found no significant difference between survivors and non-survivors in terms of age, duration of illness, and some medical parameters. However, a decline in mortality was observed with a specific combination treatment, and none of the foals treated with a certain other treatment survived.

Research Background and Purpose

  • The research aimed at reviewing and analyzing the case records of 48 foals (young horses) afflicted with Rhodococcus equi pneumonia. Rhodococcus equi is a common bacterium causing severe pneumonia in foals.
  • The review focused on understanding the foals’ responses to various antimicrobial treatments. The goal was to identify if any specific treatment strategy impacted the survival rates.

Findings

  • Out of the 48 foals, 20 survived the pneumonia while 28 didn’t. The researchers found that the age of onset of illness, duration of illness prior to admission, WBC (white blood cell count), and plasma fibrinogen content (a protein vital in clotting process) had no significant effect on the survival outcome. In other words, these characteristics were not markedly different between the survivors and non-survivors.
  • All of the foals had R. equi isolated from either a tracheobronchial aspirate (a sample from the airways) or lung specimens from necropsies (post-mortem examinations). This confirms that all foals were indeed suffering from Rhodococcus equi pneumonia.
  • All of the isolated R. equi bacteria were found to be susceptible (that is, vulnerable) to erythromycin and gentamicin in lab conditions. Susceptibility to other drugs varied, with resistance being highest to cephalothin and penicillin.

Treatment and Outcome

  • 13 out of 20 surviving foals were treated with either erythromycin or rifampin or both. This suggests a positive effect of these medicines on survival outcomes, but more data would be needed to establish a firm link.
  • There was a noticeable decline in the mortality rate with the introduction of the combination of erythromycin and rifampin, corroborating the above observation.
  • Conversely, none of the foals treated with a combination of penicillin and gentamicin survived, suggesting that this treatment strategy was ineffective.
  • Symptoms of chronic, active, non-septic synovitis (inflammation of the synovial membrane in the joints) were confirmed in 17 foals. These foals displayed joint distension (swelling), with slight or no apparent lameness.

Cite This Article

APA
Sweeney CR, Sweeney RW, Divers TJ. (1987). Rhodococcus equi pneumonia in 48 foals: response to antimicrobial therapy. Vet Microbiol, 14(3), 329-336. https://doi.org/10.1016/0378-1135(87)90120-9

Publication

Veterinary microbiology
ISSN: 0378-1135
NlmUniqueID: 7705469
Country: Netherlands
Language: English
Volume: 14
Issue: 3
Pages: 329-336

Researcher Affiliations

Sweeney, C R
  • Department of Clinical Studies, University of Pennsylvania, Kennett Square 19348.
Sweeney, R W
    Divers, T J

      MeSH Terms

      • Actinomycetales Infections / drug therapy
      • Actinomycetales Infections / veterinary
      • Animals
      • Animals, Newborn
      • Anti-Bacterial Agents / therapeutic use
      • Drug Therapy, Combination
      • Horse Diseases / drug therapy
      • Horse Diseases / microbiology
      • Horse Diseases / mortality
      • Horses
      • Pneumonia / drug therapy
      • Pneumonia / microbiology
      • Pneumonia / veterinary
      • Rhodococcus

      Citations

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