Ophthalmologic findings associated with Rhodococcus equi bronchopneumonia in foals.

OBJECTIVE

To describe ocular findings associated with Rhodococcus equi bronchopneumonia in foals, and to determine whether severity of the ocular lesions is related with outcome.

ANIMALS STUDIED

Foals diagnosed with R equi infection at the VTH-UAB from January 2002 to December 2017.

PROCEDURE

Rhodococcus equi infection was diagnosed by means of clinical signs, radiographic/ultrasonographic findings, and/or positive culture. In all the foals, a complete ophthalmic examination by a boarded ophthalmologist was performed and ocular signs were recorded and graded (0-4).

RESULTS

Thirty-nine foals were included in the study, from which 12 showed signs of bilateral anterior uveitis (30.8%). Among these, three foals were classified as mildly uveitis-affected (MUA:7.7%) and nine as severely uveitis-affected (SUA:23.1%). Five SUA foals showed green aqueous flare (5/9;55.5%). Despite the systemic treatment, 9/39 sick foals died (23.1%), the fatality rate being different between groups: SUA (4/9;44.4%), MUA (0/3; 0%) and nonuveitis-affected foals (5/27;18.5%). Among SUA foals, only one with green aqueous flare died (1/5;20%).

CONCLUSION

Bilateral anterior uveitis is highly prevalent in foals with R equi pneumonia (30.8%). The severity of anterior uveitis might be considered a nonsurvival prognostic factor and, until proven otherwise, green aqueous flare could be taken as a strongly suggestive ocular sign of the disease. Findings of this study remark the clinical relevance of performing a complete ophthalmic examination in sick foals, in order to help in the diagnosis and prognosis of uveal diseases, as well as to guaranteeing visual soundness.