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