Successful treatment of babesiosis in a south-western black rhinoceros (Diceros bicornis bicornis)

Authors

Keywords:

black rhinoceros, Babesia bicornis, babesiosis, South Africa, metapopulation management, imidocarb

Abstract

Under stressful conditions, black rhinoceroses that are sub-clinical carriers of Babesia bicornis can succumb to babesiosis. After 16 days in captivity, a five-year-old female black rhino captured for relocation presented with inappetence, abdominal discomfort and constipation. After chemical immobilisation, dry faecal balls were removed from the rectum, peripheral blood smears were made and blood collected into EDTA tubes. She was treated prophylactically for colic with flunixin meglumine, penicillin and doramectin. Piroplasms were seen on fixed and stained peripheral blood smears. Overnight she developed severe haemoglobinuria, a sign consistent with babesiosis. Subsequently, DNA extracted from a blood specimen reacted with the B. bicornis probe on Reverse Line Blot (RLB) assay, confirming the diagnosis of babesiosis. Specific treatment consisted of 14 ml imidocarb dipropionate (dosage 2.4 mg/kg) administered intramuscularly by pole syringe. Fifteen days later the patient was still moderately anaemic, with the red blood cell (RBC) count, haematocrit and haemoglobin concentration within normal ranges but on microscopic examination there was a marked RBC macrocytosis and polychromasia indicative of a regenerative anaemia. DNA extracted from blood collected at that time did not react with the B. bicornis probe on RLB assay, indicating that treatment with imidocarb had been effective. Once the patient’s appetite improved, she started gaining weight. After 82 days in captivity and 65 days after babesiosis had been diagnosed, she was released at the site where she had been captured.

Author Biographies

  • DE Zimmermann, South African National Parks

    South African National Parks, Veterinary Wildlife Services, South Africa

  • I Vorster, University of Pretoria

    Ticks & Tick-borne Diseases Research Programme, Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, South Africa

  • C Dreyer, South African National Parks

    South African National Parks, Veterinary Wildlife Services, South Africa

  • W Fowld, Amakhala Game Reserve

    Ikhala Veterinary Wildlife Services, Amakhala Game Reserve, South Africa

  • BL Penzhorn, University of Pretoria

    Ticks & Tick-borne Diseases Research Programme, Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria and National Zoological Garden, South African National Biodiversity Institute and Centre for Veterinary Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, South Africa

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Published

2022-07-18

Issue

Section

Case Report