title: Presumed immune-mediated hemolytic anemia in two foals with Rhodococcus equi infection.
abstract: OBJECTIVE
  To describe the clinical presentation, case management, and outcome in 2 foals with Rhodococcus equi infection associated with presumptive severe immune-mediated hemolytic anemia.
  
  
  METHODS
  Two foals diagnosed with R. equi pneumonia on the basis of tracheal wash cultures, thoracic radiographs, and thoracic ultrasonography were concurrently diagnosed with hemolytic anemia. Both foals required whole blood transfusions, and were treated with the antimicrobial combination of rifampin and a macrolide (eg, clarithromycin, erythromycin, or azithromycin). Dexamethasone was used to prevent further hemolysis in both foals, and to treat acute lung injury/acute respiratory distress syndrome in 1 of the foals. Both foals survived, and required prolonged antimicrobial therapy.
  
  
  CONCLUSIONS
  Although extra-pulmonary disorders are commonly diagnosed in foals infected with R. equi, hemolytic anemia is rarely described. Dexamethasone is considered the treatment of choice for immune-mediated hemolytic anemia, but may be contra-indicated in foals with severe bacterial infections. In these foals, a relatively low dose and short duration of dexamethasone was utilized in an attempt to minimize immune suppression, although early discontinuation in 1 foal precipitated a second hemolytic crisis.
authors.affiliation: George D. Widener Hospital for Large Animals, New Bolton Center, University of Pennsylvania, Kennett Square, PA 19348, USA. ijohns@rvc.ac.uk
authors.forename: Imogen C
authors.initials: IC
authors.lastname: Johns
authors.forename: Anne
authors.initials: A
authors.lastname: Desrochers
authors.forename: Kathryn L
authors.initials: KL
authors.lastname: Wotman
authors.forename: Raymond W
authors.initials: RW
authors.lastname: Sweeney
mesh_terms: D000193:Actinomycetales Infections / Q000150:complications / Q000188:drug therapy / Q000662:veterinary*; D000744:Anemia, Hemolytic, Autoimmune / Q000209:etiology / Q000382:microbiology / Q000662:veterinary*; D000818:Animals; D003907:Dexamethasone / Q000627:therapeutic use; D005938:Glucocorticoids / Q000627:therapeutic use; D006734:Horse Diseases / Q000188:drug therapy / Q000209:etiology* / Q000382:microbiology*; D006736:Horses; D018410:Pneumonia, Bacterial / Q000150:complications / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D016929:Rhodococcus equi; D016896:Treatment Outcome
chemical_list: D005938:Glucocorticoids; D003907:Dexamethasone