Successful management of multiple extrapulmonary complications associated with Rhodococcus equi pneumonia in a foal

Abstract

Summary This report describes the diagnosis and successful treatment of multiple extrapulmonary sequelae of Rhodococcus equi (R. equi) pneumonia in a 3‐month‐old filly. Bilateral uveitis and hyphaema, haemolytic anaemia and polysynovitis developed in this foal and were likely due to immune‐mediated mechanisms. The challenges associated with diagnosis and treatments of these extrapulmonary disorders are discussed. The filly was treated initially with clarithromycin and rifampin; however, a blood transfusion and immunosuppressive therapy with dexamethasone were required due to progressive haemolysis and for treatment of uveitis and polysynovitis. Bilateral hyphaema was successfully treated with intracameral injections of a recombinant tissue plasminogen activator. The development of antimicrobial resistance in R. equi was an additional challenge encountered in the management of this case and emphasises the importance of culture and in vitro antimicrobial susceptibility testing of isolates from foals with R. equi pneumonia. Extrapulmonary disorders associated with R. equi pneumonia are likely underdiagnosed and associated with a poor prognosis. This case highlights the importance of thorough and ongoing diagnostic assessment of foals with R. equi pneumonia and demonstrates that a successful outcome can be achieved with appropriate and directed treatment.

Extrapulmonary disorders associated withRhodococcus equiinfections

“…In the accompanying article, the successful management of a foal with multiple immune‐mediated EPDs associated with R. equi infection is described (Wilkes et al . ).…”

“…The development of polysynovitis in the face of initial treatment in the foal described by Wilkes et al . () is interesting and perhaps an indication of the development of antimicrobial resistance in that case (Kenney et al . ).…”

“…This lends further support to the immune‐mediated aetiology in the Wilkes et al . () case not antimicrobial‐induced haemolysis as was possible given its previous administration of trimethoprim sulphonamide.…”

“…The uveitis described by Wilkes et al . () was assumed to be immune‐mediated; however, aqueous humour collection for cytology, immunofluorescence staining and microbiological culture was not performed. Regardless of cause, uveitis has been associated with nonsurvival in both isolated case reports (Blogg et al .…”

“…The uveitis in the case of Wilkes et al . () included hyphaema, which is less commonly reported with uveitis than hypopyon and aqueous flare. The successful use of tissue plasminogen activator should be remembered in future cases of uveitis with this component of hyphaema.…”