ABSTRACT Aerial translocation of captured black rhinoceroses ( Diceros bicornis ) has been accomplished by suspending them by their feet. We expected this posture would compromise respiratory gas exchange more than would lateral recumbency. Because white rhinoceroses ( Ceratotherium simum ) immobilized with etorphine alone are hypermetabolic, with a high rate of carbon dioxide production (VCO 2 ), we expected immobilized black rhinoceroses would also have a high VCO 2 . Twelve (nine male, three female; median age 8 yr old [range: 4–25]; median weight 1,137 kg [range: 804–1,234] body weight) wild black rhinoceroses were immobilized by aerial darting with etorphine and azaperone. The animals were in lateral recumbency or suspended by their feet from a crane for approximately 10 min before data were collected. Each rhinoceros received both treatments sequentially, in random order. Six were in lateral recumbency first and six were suspended first. All animals were substantially hypoxemic and hypercapnic in both postures. When suspended by the feet, mean arterial oxygen pressure (P a O 2 ) was 42 mm Hg, 4 mm Hg greater than in lateral recumbency ( P =0.030), and arterial carbon dioxide pressure (P a CO 2 ) was 52 mm Hg, 3 mm Hg less than in lateral recumbency ( P =0.016). Tidal volume and minute ventilation were similar between postures. The mean VCO 2 was 2 mL/kg/min in both postures and was similar to, or marginally greater than, VCO 2 predicted allometrically. Suspension by the feet for 10 min did not impair pulmonary function more than did lateral recumbency and apparently augmented gas exchange to a small degree relative to lateral recumbency. The biological importance in these animals of numerically small increments in P a O 2 and decrements in P a CO 2 with suspension by the feet is unknown. Black rhinoceroses immobilized with etorphine and azaperone were not as hypermetabolic as were white rhinoceroses immobilized with etorphine.

A herd of African buffaloes ( Syncerus caffer ) was tested for Mycobacterium bovis infection using three cytokine release assays. All animals were subsequently euthanized and mycobacterial culture determined the infection prevalence (52%) and diagnostic characteristics. Sensitivities were lower than previously reported and results provide new insight into the practical utility of these assays.

Tuberculosis (TB) is a pathogenic disease that affects a range of wildlife species, including African elephants ( Loxodonta africana ). The recent discovery of fatal disease caused by infection with Mycobacterium tuberculosis in a bull elephant in the Kruger National Park (KNP), which is a bovine TB endemic area, emphasizes the importance this disease could have on both wild and captive elephant populations globally. Elephants with culture-confirmed TB have previously been shown to produce strong antibody-responses before the mycobacteria can be isolated. Therefore, we used two serologic assays that detect TB antibodies to retrospectively screen a cohort of 222 free-ranging African elephants sampled between 2004 and 2018 in KNP. The estimated TB seroprevalence for this free-roaming elephant population was between 6% (95% confidence interval [CI], 2–12%) and 9% (95% CI, 6–15%) based on the two tests. Overall, males had a higher TB seroprevalence than females, and adults (≥25 yr) had a higher TB seroprevalence than younger elephants (≤24 yr) on both rapid tests. The relatively high TB seroprevalence that we found highlighted the value of conducting retrospective studies in free-ranging wildlife populations in order to better understand the potential risk of disease.

In South Africa, the largest proportion of the African wild dog ( Lycaon pictus ) population resides in regions where buffaloes have a high prevalence of Mycobacterium bovis , the causative agent of bovine tuberculosis (bTB). Recent reports of deaths of wild dogs associated with bTB have raised concerns regarding the threat this disease might pose for this species. In order to understand the potential impact of the disease in wild dogs, diagnostic tools are required to identify infected individuals. The interferon gamma (IFN-γ) release assay (IGRA) is commonly used for tuberculosis (TB) screening of humans, cattle, and other species, and the aim of this study was to develop an IGRA for wild dogs to detect immune sensitization. Blood was collected from immobilized wild dogs from the Ann van Dyk Cheetah Centre (AvDCC; n =9) and Kruger National Park (KNP; n =31). Heparinized whole blood was incubated overnight in QuantiFERON ® -TB Gold (QFT) blood collection tubes and with selected mitogens, after which the plasma fraction was harvested. Three canine IFN-γ enzymelinked immunosorbent assays (ELISAs) were compared for detection of wild dog IFN-γ in plasma and the R&D Quantikine canine IFN-γ ELISA was selected for measurement of M. bovis -specific IFN-γ release in plasma samples. An IGRA result was calculated as the concentration in plasma derived from the QFT TB Antigen tubes minus that in the QFT Nil tube. An IGRA cut-off value was calculated using the IGRA results of M. bovis- unexposed individuals from AvDCC. Using this cut-off value, 74% (23/31) of M. bovis -exposed KNP wild dogs were IGRA positive, indicating immune sensitization to TB antigens in these animals. Three M. bovis culture-positive wild dogs from KNP had IFN-γ concentrations between 758 and 1,445 pg/mL, supporting this interpretation. This warrants further investigation into the prevalence of M. bovis infection in the KNP population.

Lion ( Panthera leo ) populations, classified as vulnerable under the International Union for Conservation of Nature red list of threatened species, are facing a variety of threats, including tuberculosis (TB) caused by Mycobacterium bovis . The lack of knowledge on pathogenesis and diagnosis of TB, the prolonged course of the disease, the existence of subclinical infection, and nonspecific clinical signs hamper management of TB in both free-ranging and captive lion populations. Early and accurate antemortem diagnosis of M. bovis infections is important for disease management. In this study, we investigate the suitability of the single intradermal cervical test (SICT), developed with free-ranging Kruger National Park (KNP) lions exposed to M. bovis , for use in other lion populations. Using the recommended interpretation, the specificity of the SICT was low in disease-free captive lions, leading to false-positive diagnoses in 54% of individuals in the present study. Alternative interpretations of the tuberculin skin test are proposed that significantly reduce false-positive diagnosis in the sampled captive lions without significantly affecting diagnoses in the KNP lions; these changes may facilitate screening for M. bovis infection regardless of the exposure status of the lion population being investigated.