The black and rufous elephant shrew (Order Macroscelidea) is classified as vulnerable (IUCN); breeding programs were established in AZA facilities in 2000.1 Mycobacteriosis is the most common cause of death in captive adults of this species. This presentation describes mycobacterial infection in 13 black and rufous elephant shrews from five institutions.
Common clinical findings are lameness and joint swelling +/- associated bony lysis. Weight loss, lethargy, respiratory signs, internal granulomas, and non-regenerative anemia may develop as infection progresses. Diagnosis is confirmed by acid fast staining, culture, and PCR of granuloma aspirates or biopsies. M. intracellulare is identified most frequently.
Multi-drug antibiotic protocols including azithromycin, rifabutin, and ethambutol have been administered based on recommendations in humans and appear relatively well tolerated.3 Medical and surgical management have had limited success; infection often results in euthanasia. Mycobacteriosis is often widely disseminated at necropsy. Histologic findings include pyogranulomatous and necrotizing periarticulitis, synovitis, osteomyelitis, lymphadenitis, pneumonia, vasculitis, pericarditis, myocarditis, and hepatitis. Suppurative inflammation is observed more frequently than is typically reported with mycobacterial infection in other species.4,8
Common sources of M. intracellulare infection include soil and municipal water where it can remain viable for extended periods.2,7 Management practices to decrease environmental contamination within enclosures are recommended. Compromised immune function, possibly secondary to nutritional, genetic, or viral factors, may contribute to this species’ susceptibility to infection.5,6,9 Further investigation of the nutritional requirements, genetic diversity, and immune status of this species as well as of antibiotic sensitivity patterns and pharmacokinetics is warranted to improve prevention and treatment.
The authors wish to thank all those who contribute to the care of black and rufous elephant shrews in captivity. Special thanks go to Drs. Peter Nichols and Amanda Guthrie for providing case information from the Peoria Zoo and Zoo Boise, respectively. A grant from the Philadelphia Zoo Staff Conservation and Science Fund provided funding for the PCR and sequencing of mycobacterial organisms by the Molecular, Serological, and Virological Diagnostics Lab at Yale University School of Medicine.
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