Extrapulmonary disorders associated with Rhodococcus equi infection in foals: 150 cases (1987-2007)

• Published in: Journal of the American Veterinary Medical Association Vol. 235; no. 7; pp. 855 - 863
• Main Authors: Reuss, Sarah M, Chaffin, M. Keith, Cohen, Noah D
• Format: Journal Article
• Language: English
• Published: United States 01-10-2009
• Subjects: Abdominal Abscess - complications; Abdominal Abscess - microbiology; Abdominal Abscess - veterinary; Actinomycetales Infections - complications; Actinomycetales Infections - microbiology; Actinomycetales Infections - mortality; Actinomycetales Infections - veterinary; animal pathogenic bacteria; Animals; bacterial infections; blood chemistry; Central Nervous System Diseases - complications; Central Nervous System Diseases - microbiology; Central Nervous System Diseases - veterinary; clinical examination; disease diagnosis; disease prevalence; extrapulmonary disorders; foals; Gastrointestinal Diseases - complications; Gastrointestinal Diseases - microbiology; Gastrointestinal Diseases - veterinary; heart rate; Hematologic Diseases - complications; Hematologic Diseases - microbiology; Hematologic Diseases - veterinary; Hepatitis, Animal - complications; Hepatitis, Animal - microbiology; horse diseases; Horse Diseases - microbiology; Horses; lungs; Lymphadenitis - complications; Lymphadenitis - microbiology; Lymphadenitis - veterinary; mortality; Musculoskeletal Diseases - complications; Musculoskeletal Diseases - microbiology; Musculoskeletal Diseases - veterinary; neutrophils; pathogen identification; Peritonitis - complications; Peritonitis - microbiology; Peritonitis - veterinary; prognosis; Retrospective Studies; Rhodococcus equi; risk factors; signs and symptoms (animals and humans); urea nitrogen; Uveitis - complications; Uveitis - microbiology; Uveitis - veterinary
• ISSN: 0003-1488; 1943-569X
• DOI: 10.2460/javma.235.7.855

To describe frequency, types, and clinical outcomes of extrapulmonary disorders (EPDs) in foals in which Rhodococcus equi infection was diagnosed, and to identify factors determined at the time of admission that differentiated foals that developed EPDs from foals with R equi infection identified only in the lungs.
Retrospective case series.
150 foals aged 3 weeks to 6 months with a diagnosis of R equi infection.
Medical records were reviewed for information on date of admission, signalment, history, clinical signs, diagnostic testing, treatment, duration of hospitalization, invoice, and outcome. For each EPD identified, further information was collected on the identification, location, treatment, and outcome of the lesion.
Of 150 foals with R equi infections, 111 (74%) had at least 1 of 39 EPDs. Survival was significantly higher among foals without EPDs (32/39 [82%]) than among foals with EPDs (48/111 [43%]), but many EPDs were only recognized after death. Risk factors significantly associated with EPDs included referral status, duration of clinical signs prior to admission, leukocytosis, and neutrophilia. Foals with EPDs also had a higher heart rate and BUN concentration than foals without.
Practitioners should recognize that extrapulmonary manifestations of R equi occur with high prevalence affecting diverse organ systems, that multiple systems are generally affected when EPDs occur, and that suspicion of R equi infection should prompt evaluation and monitoring of extrapulmonary sites. Improved recognition of the presence of these disorders will help practitioners to better advise their clients in the treatment and outcome of foals with R equi infections.