Clinicopathological features, molecular diagnosis and treatment of epizootic lymphangitis in a donkey at a university zoological garden: a case report

Abstract

Report on epizootic lymphangitis, a chronic contagious zoonosis of Equidae caused by Histoplasma capsulatum var. farciminosum characterized clinically by pyogranulomatous multifocal dermatitis with lymphadenitis, is rare in donkeys. This case reports a 6-year-old, 200-kg local male donkey at the University of Ibadan zoological garden with wounds on its dorsum which developed into ulcerative lesions on the left cranial thoracic region. The lesions were also along the lymphatic drainage of the left infrascapular area down to the girth with extensive nodular lesions on the skin, characteristic focal ulcers and fenestrations along the left flank. The ulcers were recurrent with blockage of the left lymphatic drainage causing ventral edema of the sternum extending to the prepuce and the left forelimb. The wound was managed for about 1 year but remained persistent with episodes of apparent healing, scarification and recurrence. Tentative diagnosis of epizootic lymphangitis was made. Blood sample, pus swab and aspirated exudate were collected for confirmatory diagnosis using light microscopy and polymerase chain reaction (PCR) to detect and amplify a fragment of the internal transcribed spacer-2 (ITS-2) gene. These techniques detected Histoplasma capsulatum var. farciminosum, which informed the use of appropriate therapeutic agents, providone iodine wash, and griseofulvin cream and tablets for 3 weeks to treat the disease condition.