Veterinary journal (London, England : 1997)2011; 192(1); 20-26; doi: 10.1016/j.tvjl.2011.08.014

Rhodococcus equi pneumonia in the foal–part 1: pathogenesis and epidemiology.

Abstract: Rhodococcus equi pneumonia is a worldwide infectious disease of major concern to the equine breeding industry. The disease typically manifests in foals as pyogranulomatous bronchopneumonia, resulting in significant morbidity and mortality. Inhalation of aerosolised virulent R. equi from the environment and intracellular replication within alveolar macrophages are essential components of the pathogenesis of R. equi pneumonia in the foal. Recently documented evidence of airborne transmission between foals indicates the potential for an alternative contagious route of disease transmission. In the first of this two-part review, the complexity of the host, pathogen and environmental interactions that underpin R. equi pneumonia will be discussed through an exploration of current understanding of the epidemiology and pathogenesis of R. equi pneumonia in the foal.
Publication Date: 2011-10-19 PubMed ID: 22015138DOI: 10.1016/j.tvjl.2011.08.014Google Scholar: Lookup
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Rhodococcus equi pneumonia, a global issue affecting young horses, generally results in severe lung disease, posing a serious threat to horse breeding. This research paper discusses the pathogenesis and epidemiology of this disease, including its transmission through the air and replication within lung cells.

Epidemiology of Equine Pneumonia

  • Known as Rhodococcus equi pneumonia, the disease is a significant concern to the horse breeding industry worldwide.
  • This illness typically manifests in young horses, or foals, resulting in a serious lung infection called pyogranulomatous bronchopneumonia. This can cause notable sickness and even death among foal populations.
  • Recently, evidence has been documented suggesting that the disease can be transmitted through the air, demonstrating the potential for alternative contagious pathways of transmission.

Pathogenesis of Rhodococcus equi pneumonia

  • The bacteria causing Rhodococcus equi pneumonia, often aerosolized and present in the environment, get inhaled by foals.
  • Once inhaled, these bacteria begin replicating within the foal’s lung cells, known as alveolar macrophages, serving a key role in the development of this disease.

Overall Implication

  • This paper provides an exploration of the present understanding of the epidemiology and pathogenesis of Rhodococcus equi pneumonia in foals. The study offers insights into the complex nature of the host, pathogen, and environmental interactions that contribute to this disease.
  • This review is part one of a two-part study. It sets the stage for an expanded discussion on the complexities and potential treatment strategies for Rhodococcus equi pneumonia in foals.

Cite This Article

Muscatello G. (2011). Rhodococcus equi pneumonia in the foal–part 1: pathogenesis and epidemiology. Vet J, 192(1), 20-26.


ISSN: 1532-2971
NlmUniqueID: 9706281
Country: England
Language: English
Volume: 192
Issue: 1
Pages: 20-26

Researcher Affiliations

Muscatello, Gary
  • Faculty of Veterinary Science, University of Sydney, NSW 2006, Australia.

MeSH Terms

  • Actinomycetales Infections / epidemiology
  • Actinomycetales Infections / microbiology
  • Actinomycetales Infections / transmission
  • Actinomycetales Infections / veterinary
  • Age Factors
  • Animals
  • Animals, Newborn / microbiology
  • Bronchopneumonia / epidemiology
  • Bronchopneumonia / microbiology
  • Bronchopneumonia / veterinary
  • Horse Diseases / epidemiology
  • Horse Diseases / microbiology
  • Horse Diseases / transmission
  • Horses
  • Host-Pathogen Interactions
  • Pneumonia, Bacterial / epidemiology
  • Pneumonia, Bacterial / microbiology
  • Pneumonia, Bacterial / transmission
  • Pneumonia, Bacterial / veterinary
  • Prevalence
  • Rhodococcus equi / pathogenicity
  • Rhodococcus equi / physiology
  • Virulence


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