Adrian S.W. Tordiffe

Pulmonary Infection due to Mycobacterium bovis in a Black Rhinoceros (Diceros bicornis minor) in South Africa

We report a case of tuberculosis due to infection with Mycobacterium bovis in an elderly male black rhinoceros (Diceros bicornis minor) from the Limpopo Province in South Africa. The animal was euthanized due to very poor condition, old age, and dental attrition. Necropsy examination revealed two small nonencapsulated granulomas (∼40-mm diameter) in the dorsocaudal lobe of the left lung. Sequencing of isolated crude lung tissue PCR product and boiled lung culture samples confirmed that the causative organism was M. bovis. Genotyping revealed limited similarities with M. bovis strains isolated thus far from South African cattle or wildlife. The source of the infection could not be determined. This case illustrates that M. bovis could impact conservation of free-ranging rare and endangered species. Effective diagnostics are urgently needed for different animal species, such as white or black rhinoceroses, to certify with a reasonable degree of certainty that these animals are free of tuberculosis in natural habitats.

Determining Adrenocortical Activity as a Measure of Stress in African Buffalo (Syncerus caffer) Based on Faecal Analysis

Little is known about the levels of stress experienced by African buffalos affected by injury, disease, or socio-ecological and anthropogenic factors. To be able to start filling this gap, we examined the suitability of two 11-oxoaetiocholanolone enzyme-immunoassays (EIAs) detecting 11,17 dioxoandrostanes (11,17-DOA) as well as faecal glucocorticoid metabolites (FGMs) with a 5&bgr;-3&agr;-ol-11-one structure (3&agr;,11oxo-CM), respectively, for monitoring stress-related physiological responses in African buffalo. An adrenocorticotrophic hormone (ACTH) challenge in one male and one female housed at Mokopane Biodiversity Conservation Centre, South Africa, showed a threefold increase in circulating Cortisol levels in a sample taken 40 min post-injection. Corresponding 11,17-DOA levels increased tenfold (female) and 15-fold (male) above baseline, and 3&agr;,11oxo-CM concentrations increased ninefold (female) and 12-fold (male) above pre-injection levels, indicating that both EIAs are suitable for measuring FGMs in African buffalo.In addition, 11,17-DOA levels monitored during the adaptation process of individual housing revealed an up to 14-fold elevation in FGMs. Storage of faeces at ambient temperature for up to 16 h post-defecation resulted in an significant increase in 11,17-DOA levels 2 h after defecation. Finally, higher individual baseline 11,17-DOA concentrations were found in samples defecated overnight, indicating a possible diurnal effect in excretion of FGMs in African buffalo.

New Insights into Samango Monkey Speciation in South Africa

The samango monkey is South Africas only exclusively forest dwelling primate and represents the southernmost extent of the range of arboreal guenons in Africa. The main threats to South Africas forests and thus to the samango are linked to increasing land-use pressure and increasing demands for forest resources, resulting in deforestation, degradation and further fragmentation of irreplaceable habitats. The species belongs to the highly polytypic Cercopithecus nictitans group which is sometimes divided into two species C. mitis and C. albogularis. The number of subspecies of C. albogularis is also under debate and is based only on differences in pelage colouration and thus far no genetic research has been undertaken on South African samango monkey populations. In this study we aim to further clarify the number of samango monkey subspecies, as well as their respective distributions in South Africa by combining molecular, morphometric and pelage data. Overall, our study provides the most comprehensive view to date into the taxonomic description of samango monkeys in South Africa. Our data supports the identification of three distinct genetic entities namely; C. a. labiatus, C. a. erythrarchus and C. a. schwarzi and argues for separate conservation management of the distinct genetic entities defined by this study.

CYSTINE UROLITHIASIS IN A CARACAL (CARACAL CARACAL)

In July 2009, a 14-yr-old male caracal (Caracal caracal) at the National Zoological Gardens of South Africa was found, on abdominal ultrasound, to have a single large cystolith. The cystolith was removed, and the composition was determined to be 100% cystine. Blood and urine samples were also collected from three other apparently healthy caracals at the zoo and were submitted, together with the samples from the affected animal, for analysis using gas chromatograph mass spectrometry for cystine, lysine, alanine, and ornithine levels. The cystine levels in the urine, the fractional excretion of cystine, and the normalized excretion of cystine (micromol/g of creatinine) were all higher in the affected caracal than in the healthy animals. Only a single other case of cystine urolithiasis has been previously reported in any wild felid in the literature.

Ultrasonographic adrenal gland findings in healthy semi-captive cheetahs (Acinonyx jubatus)

Cheetahs in captivity are believed to suffer from stress predisposing them to poor health. To date fecal glucocorticoids have been used as a non-invasive indicator of chronic stress. This study examines, the feasibility of transabdominal adrenal gland ultrasonography in cheetahs and determined normal adrenal measurements that can potentially be used as a more reliable indicator of chronic stress and/or adrenal function. Thirty-three adult cheetahs, aged between 2 and 13 years, accommodated in large off-display camps were examined over 9 days under general anesthesia. The adrenals were readily identified, with the right adrenal being more difficult to find and measure than the left, and were smaller than those expected in similar sized dogs. The left adrenal was shorter and slightly more oval shaped than the right with a length and cranial pole width at a 95% prediction interval of 16.3-22.4 and 4.1-8.7 mm. The same measurements for the right adrenal were 16.8-26.2 and 3.4-10.8 mm, respectively. Corticomedullary ratios were larger for the left adrenal. When corrected for body size, females had significantly longer and greater left adrenal corticomedullary ratios than males. Adrenal measurements did not correlate with left renal length, body size measurements, or enclosure size. Measurements that increased with age included the cortical and total adrenal widths. Adrenal ultrasonography offers potential benefits in assessment of individual cheetah adrenal pathology or the evaluation of stress induced adrenomegally especially in combination with other evaluations such as non-invasive fecal glucocorticoid analyses. Zoo Biol. 35:260-268, 2016.

Comparative serum fatty acid profiles of captive and free-ranging cheetahs (Acinonyx jubatus) in Namibia

Cheetahs (Acinonyx jubatus) are highly specialised large felids, currently listed as vulnerable on the IUCN red data list. In captivity, they are known to suffer from a range of chronic non-infectious diseases. Although low heterozygosity and the stress of captivity have been suggested as possible causal factors, recent studies have started to focus on the contribution of potential dietary factors in the pathogenesis of these diseases. Fatty acids are an important component of the diet, not only providing a source of metabolisable energy, but serving other important functions in hormone production, cellular signalling as well as providing structural components in biological membranes. To develop a better understanding of lipid metabolism in cheetahs, we compared the total serum fatty acid profiles of 35 captive cheetahs to those of 43 free-ranging individuals in Namibia using gas chromatography-mass spectrometry. The unsaturated fatty acid concentrations differed most remarkably between the groups, with all of the polyunsaturated and monounsaturated fatty acids, except arachidonic acid and hypogeic acid, detected at significantly lower concentrations in the serum of the free-ranging animals. The influence of age and sex on the individual fatty acid concentrations was less notable. This study represents the first evaluation of the serum fatty acids of free-ranging cheetahs, providing critical information on the normal fatty acid profiles of free-living, healthy individuals of this species. The results raise several important questions about the potential impact of dietary fatty acid composition on the health of cheetahs in captivity.

Reference intervals for selected serum biochemistry analytes in Cheetahs (Acinonyx jubatus)

Published haematologic and serum biochemistry reference intervals are very scarce for captive cheetahs and even more for free-ranging cheetahs. The current study was performed to establish reference intervals for selected serum biochemistry analytes in cheetahs. Baseline serum biochemistry analytes were analysed from 66 healthy Namibian cheetahs. Samples were collected from 30 captive cheetahs at the AfriCat Foundation and 36 free-ranging cheetahs from central Namibia. The effects of captivity-status, age, sex and haemolysis score on the tested serum analytes were investigated. The biochemistry analytes that were measured were sodium, potassium, magnesium, chloride, urea and creatinine. The 90% confidence interval of the reference limits was obtained using the non-parametric bootstrap method. Reference intervals were preferentially determined by the non-parametric method and were as follows: sodium (128 mmol/L - 166 mmol/L), potassium (3.9 mmol/L - 5.2 mmol/L), magnesium (0.8 mmol/L - 1.2 mmol/L), chloride (97 mmol/L - 130 mmol/L), urea (8.2 mmol/L - 25.1 mmol/L) and creatinine (88 µmol/L - 288 µmol/L). Reference intervals from the current study were compared with International Species Information System values for cheetahs and found to be narrower. Moreover, age, sex and haemolysis score had no significant effect on the serum analytes in this study. Separate reference intervals for captive and free-ranging cheetahs were also determined. Captive cheetahs had higher urea values, most likely due to dietary factors. This study is the first to establish reference intervals for serum biochemistry analytes in cheetahs according to international guidelines. These results can be used for future health and disease assessments in both captive and free-ranging cheetahs.Published haematologic and serum biochemistry reference intervals are very scarce for captive cheetahs and even more for free-ranging cheetahs. The current study was performed to establish reference intervals for selected serum biochemistry analytes in cheetahs. Baseline serum biochemistry analytes were analysed from 66 healthy Namibian cheetahs. Samples were collected from 30 captive cheetahs at the AfriCat Foundation and 36 free-ranging cheetahs from central Namibia. The effects of captivity-status, age, sex and haemolysis score on the tested serum analytes were investigated. The biochemistry analytes that were measured were sodium, potassium, magnesium, chloride, urea and creatinine. The 90% confidence interval of the reference limits was obtained using the non-parametric bootstrap method. Reference intervals were preferentially determined by the non-parametric method and were as follows: sodium (128 mmol/L – 166 mmol/L), potassium (3.9 mmol/L – 5.2 mmol/L), magnesium (0.8 mmol/L – 1.2 mmol/L), chloride (97 mmol/L – 130 mmol/L), urea (8.2 mmol/L – 25.1 mmol/L) and creatinine (88 µmol/L – 288 µmol/L). Reference intervals from the current study were compared with International Species Information System values for cheetahs and found to be narrower. Moreover, age, sex and haemolysis score had no significant effect on the serum analytes in this study. Separate reference intervals for captive and free-ranging cheetahs were also determined. Captive cheetahs had higher urea values, most likely due to dietary factors. This study is the first to establish reference intervals for serum biochemistry analytes in cheetahs according to international guidelines. These results can be used for future health and disease assessments in both captive and free-ranging cheetahs.

Non-invasive assessment of adrenocortical activity as a measure of stress in giraffe (Giraffa camelopardalis)

BackgroundNumbers of giraffes are declining rapidly in their native habitat. As giraffe research and conservation efforts increase, the demand for more complete measures of the impact of conservation interventions and the effects of captive environments on animal health and welfare have risen. We compared the ability of six different enzyme immunoassays to quantify changes in fecal glucocorticoid metabolites (FGM) resulting from three sources: adrenocorticotropic hormone stimulation test, transport, and time of day that samples were collected.ResultsTwo male giraffes underwent ACTH injections; all six assays detected FGM increases following injection for Giraffe 1, while only three assays detected FGM increases following injection for Giraffe 2. Consistent with other ruminant species, the two 11-oxoetiocholanolone assays (one for 11,17-dioxoandrostanes and the other for 3α,11-oxo metabolites) measured the most pronounced and prolonged elevation of FGM, while an assay for 3β,11β-diol detected peaks of smaller magnitude and duration. Both of the 11-oxoetiocholanolone assays detected significant FGM increases after transport in Giraffes 3–7, and preliminary data suggest FGM detected by the assay for 11,17-dioxoandrostanes may differ across time of day.ConclusionsWe conclude the assay for 11,17-dioxoandrostanes is the most sensitive assay tested for FGM in giraffes and the assay for FGM with a 5β-3α-ol-11-one structure is also effective. 11-oxoetiocholanolone enzyme immunoassays have now been demonstrated to be successful in a wide variety of ruminant species, providing indirect evidence that 5β-reduction may be a common metabolic pathway for glucocorticoids in ruminants. As FGM peaks were detected in at least some giraffes using all assays tested, giraffes appear to excrete a wide variety of different FGM. The assays validated here will provide a valuable tool for research on the health, welfare, and conservation of giraffes.

Measuring Faecal Epi-Androsterone as an Indicator of Gonadal Activity in Spotted Hyenas (Crocuta crocuta)

Enzyme immunoassays (EIA) that measure faecal testosterone metabolites (fTM) are useful tools to monitor gonadal activity. The aim of this study was to validate an “in-house” epiandrosterone EIA to monitor fTM in spotted hyenas. FTM were characterised in a male and a female hyena that each received an injection of 3H-testosterone. High-performance liquid chromatography (HPLC) analyses revealed a cluster of highly polar enzyme-hydrolysable hormone metabolite conjugates. We performed hydrolysis using β-glucuronidase to deconjugate metabolites and improve sensitivity of the assay. Because β-glucuronidase from Helix pomatia has been reported to bias testosterone measurements in some species, we compared the enzymatic activity of the commonly used β-glucuronidase extracted from H. pomatia with the same enzyme from Escherichia coli. Our results showed that β-glucuronidases from both sources produced similar results from spotted hyena faeces. We therefore hydrolysed samples with H. pomatia enzymes. HPLC analyses also demonstrated that following hydrolysis the epiandrosterone EIA measured significant amounts of immunoreactive metabolites corresponding to radiolabelled metabolites in both sexes. Additionally, HPLC and GC-MS analyses confirmed the presence of epiandrosterone in faeces of spotted hyenas. The biological relevance of the epiandrosterone EIA was validated by demonstrating (1) a significant increase in fTM levels in response to a testosterone injection within 16 h, (2) no biological responsiveness to an adrenocorticotropic hormone (ACTH) injection and (3) significant differences in fTM levels between juvenile males and adult immigrant males in a free-ranging wild population. Our results clearly demonstrate that the epiandrosterone EIA is a reliable non-invasive method to monitor gonadal activity in spotted hyenas.

Interspecific hybridization between greater kudu and nyala

Abstract Hybridization of wildlife species, even in the absence of introgression, is of concern due to wasted reproductive effort and a reduction in productivity. In this study we detail an accidental mating between a female nyala (Tragelaphus angasii) and a male greater kudu (T. strepsiceros). The hybrid was phenotypically nyala and was identified as such based on mitochondrial DNA. Further genetic analysis based on nine microsatellite markers, chromosome number and chromosome morphology however, confirmed its status as an F1 hybrid. Results obtained from a reproductive potential assessment indicated that this animal does not have the potential to breed successfully and can be considered as sterile.