Hooo-Hooo Volume 11 Nr 1 - Page 12

WildLife Group of the SAVA abstracts From African Wildlife Conference 2017 OVERVIEW OF DISEASE OF AFRICAN RHINOCEROSES https://vimeo.com/207942426 Michele A. Miller NRF South African Research Chair in Animal TB, Stellenbosch University ABSTRACT: With increasing threats from poaching and habitat fragmentation, African rhinoceros are being more intensively managed. Therefore, wildlife veterinarians need to be aware of diseases, diagnostic and therapeutic approaches that may be required to address health issues in these species. This presentation provides an overview of some of the infectious and non-infectious diseases that have been reported in black and white rhinoceros. The information serves as a foundation for dealing with morbidity and mortality in African rhinoceros. BACTERIAL DISEASES Salmonellosis – This is a clinically important disease of rhinos, especially in confinement. Clinical syndromes vary; non-specific signs, anorexia, and lethargy; enteric disease with diarrhoea or bloody faeces, colic; septicaemia, which may be fatal. Animals may recover and eliminate infection or they may become a carrier with inapparent shedding or intermittent clinical signs. In a study of black rhinos in a zoo, four of six animals were intermittent shedders with 2.4% of faecal samples culture-positive. Diagnosis is based on 12 culture or PCR and serotyping. Isolation of Salmonella in an ill animal does NOT necessarily identify this as a cause of the clinical signs. Rhinos on antibiotics or immunocompromised by other disease or stress may shed bacteria. Intermittent shedding requires that samples are submitted for multiple cultures. Serotyping is based on cell wall and flagellar antigens, as well as biochemical characteristics; this is important epidemiologically. Treatment is primarily supportive, including fluid therapy, nutritional support, and anti- inflammatories. Antibiotics may be used but should be based on sensitivities since therapy may lead to a carrier state or antibiotic resistance. Generally antibiotics are used in more serious cases, young, or compromised animals. Predisposing factors for salmonellosis include stressful events, such as transport or introductions, changes in feed resulting in gut flora imbalance, and concurrent disease. Preventive measures should minimize stress, provide good hygiene, and isolation of any animals that are shedding bacteria. Tuberculosis (Mycobacteriosis) – This is a sporadic disease with significant clinical and regulatory consequences. In rhinos it can be caused by either M. bovis or M. tuberculosis. TB has been documented in white, black, greater one-horned and Sumatran rhinos in captivity. Anecdotal evidence suggests that browsing rhinos may be more susceptible. TB typically affects adults. Clinical signs vary – dyspnoea, coughing, nasal discharge, weight loss, weakness, or lethargy. Often animals are asymptomatic until disease is advanced, which may take months to years. At least 21 cases have been documented in African rhinos in zoos. There have been 4 cases of documented M. bovis infection in black rhinos in