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An atypical extrapulmonary presentation of rhodococcus equi infection in a foal: a case report.
Abstract: Rhodococcus equi infection in foals is primarily associated with pulmonary disease but may also present with extrapulmonary manifestations (Giguère et al. 2011; Reuss et al. 2009). Hemolytic anemia is a rare and poorly described complication, with only a single previous report of presumed immune-mediated hemolytic anemia in foals affected by R. equi. This case report describes the clinical presentation, diagnostic findings, disease progression, and postmortem examination of a 4-month-old Holsteiner foal with confirmed R. equi infection and severe anemia consistent with a presumed immune-mediated hemolytic process. Despite intensive antimicrobial and supportive therapy, the foal's condition progressively deteriorated, and euthanasia was performed.
© 2026. The Author(s), under exclusive licence to Springer Nature B.V.
Publication Date: 2026-08-26 PubMed ID: 42645630PubMed Central: 7256024DOI: 10.1007/s11259-026-11469-wGoogle Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Case Reports
Summary
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An unusual case of Rhodococcus equi infection in a young foal is described, focusing on an uncommon complication of severe anemia likely caused by the immune system. Despite treatment, the foal’s condition worsened, leading to euthanasia.
Background
- Rhodococcus equi is a bacterial pathogen primarily causing pneumonia in foals, which are young horses.
- While lung involvement is common, R. equi can sometimes cause extrapulmonary (outside the lungs) symptoms.
- One rare complication noted is hemolytic anemia, where red blood cells are destroyed prematurely, often due to immune system activity.
- Prior to this report, only one case of presumed immune-mediated hemolytic anemia linked to R. equi infection in foals had been documented.
Case Presentation
- The subject is a 4-month-old Holsteiner foal diagnosed with R. equi infection.
- The foal exhibited severe anemia that was consistent with immune-mediated hemolytic anemia, meaning the immune system was likely attacking its own red blood cells.
- Clinical signs, diagnostic data, and disease progression were documented.
Diagnostic Findings
- Confirmation of R. equi infection was established via appropriate microbiological methods.
- The severity of anemia was assessed through blood tests showing low red blood cell counts.
- Clinical signs consistent with anemia and infection were evident, such as weakness and pallor.
Treatment and Outcome
- The foal underwent intensive antimicrobial therapy aimed at controlling R. equi infection.
- Supportive care was provided to manage anemia and other clinical complications.
- Despite aggressive treatment, the foal’s health deteriorated progressively.
- Due to worsening condition and poor prognosis, euthanasia was elected.
Postmortem Examination
- Autopsy was performed to further understand the extent and nature of disease.
- Findings confirmed extensive infection consistent with R. equi.
- Evidence supported severe hemolytic anemia, corroborating the clinical suspicion of immune-mediated red blood cell destruction.
Significance of the Case Report
- This case highlights an atypical, severe extrapulmonary manifestation of R. equi infection in foals.
- It provides clinical and pathological evidence supporting immune-mediated hemolytic anemia as a rare complication of R. equi infection.
- The report emphasizes the need for awareness of such complications in clinical practice for prompt diagnosis and management.
- It contributes to the limited literature on extrapulmonary effects of R. equi and may encourage further research on immune-mediated mechanisms in foals with this infection.
Cite This Article
APA
Tamulionytė-Skėrė R, Mickevičienė I, Gruodytė R, Paulavičiūtė B, Šiugždinienė R, Hinksman J, Urbonavičiūtė A, Driukė MU.
(2026).
An atypical extrapulmonary presentation of rhodococcus equi infection in a foal: a case report.
Vet Res Commun, 50(6), 532.
https://doi.org/10.1007/s11259-026-11469-w Publication
Researcher Affiliations
- Large Animal Clinic, Veterinary Academy, Lithuanian University of Health Sciences, Tilžės street 18, Kaunas, 44307, Lithuania. raimonda.tamulionyte-skere@lsmu.lt.
- Large Animal Clinic, Veterinary Academy, Lithuanian University of Health Sciences, Tilžės street 18, Kaunas, 44307, Lithuania.
- Large Animal Clinic, Veterinary Academy, Lithuanian University of Health Sciences, Tilžės street 18, Kaunas, 44307, Lithuania.
- Large Animal Clinic, Veterinary Academy, Lithuanian University of Health Sciences, Tilžės street 18, Kaunas, 44307, Lithuania.
- Microbiological Research Laboratory, Veterinary Faculty Institute of Microbiology and Virology, Lithuanian University Of Health Sciences, Tilžės street 18, Kaunas, 44307, Lithuania.
- Large Animal Clinic, Veterinary Academy, Lithuanian University of Health Sciences, Tilžės street 18, Kaunas, 44307, Lithuania.
- Large Animal Clinic, Veterinary Academy, Lithuanian University of Health Sciences, Tilžės street 18, Kaunas, 44307, Lithuania.
- Large Animal Clinic, Veterinary Academy, Lithuanian University of Health Sciences, Tilžės street 18, Kaunas, 44307, Lithuania.
MeSH Terms
- Animals
- Actinomycetales Infections / veterinary
- Actinomycetales Infections / microbiology
- Actinomycetales Infections / diagnosis
- Actinomycetales Infections / pathology
- Actinomycetales Infections / drug therapy
- Rhodococcus equi / isolation & purification
- Horses
- Horse Diseases / microbiology
- Horse Diseases / diagnosis
- Horse Diseases / pathology
- Horse Diseases / drug therapy
- Anti-Bacterial Agents / therapeutic use
- Fatal Outcome
- Anemia, Hemolytic / veterinary
- Anemia, Hemolytic / microbiology
Conflict of Interest Statement
Declarations. Informed consent: was obtained from all individual participants included in the study. Consent to Publish: declaration: The authors affirm that research participants owners provided informed consent for publication of all images and figures in the manuscript. Competing interests: The authors declare no competing interests.
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