Vitamin D status in chimpanzees in human care: a Europe wide study.

While vitamin D deficiency is a public health concern in humans, comparatively little is known about vitamin D levels in non-human primates. Vitamin D plays a crucial role in overall health and its deficiency is associated with a range of disorders, including cardiovascular disease, which is a leading cause of death in great apes. Serum samples (n = 245) from chimpanzees (Pan troglodytes) housed at 32 European zoos were measured for 25-hydroxyvitamin D2, 25-hydroxyvitamin D3 and total 25-hydroxyvitamin D (25-OHD) using liquid chromatography and tandem mass spectrometry. Of these samples, 33.1% indicated inadequate vitamin D status, using the human reference interval (25-OHD < 50 nmol/L). The season of the year, health status of the animal, and the provision of daily outdoor access had a significant effect on vitamin D status. This is the first large-scale study on vitamin D status of non-human great apes in human care. Inadequate 25-OHD serum concentrations are widespread in the chimpanzee population in Europe and could be a risk factor for the development of idiopathic myocardial fibrosis, a major cause of mortality in this species, as well as other diseases. A review of husbandry and nutrition practices is recommended to ensure optimal vitamin D supply for these endangered animals.

Assessing the Educational Value of a Zoo Placement for Veterinary Students: A Report on Student Feedback and Perceptions.

Zoological medicine is an expanding field with limited practical training opportunities for veterinary students. Those training programs that do exist require significant financial and resource investment by both veterinary schools and the zoological organizations involved. This article summarizes the findings of a retrospective survey of students carried out to ascertain the educational value of a compulsory 5-day-long zoo clinical placement for final-year veterinary students. We aimed to explore the placement's potential impact on students' knowledge and attitudes toward zoological medicine and the role of modern zoos and conservation. Data were collected by means of an end-of-placement questionnaire (N = 200) and statistically analyzed for pre- versus post-placement changes and the effect of pre-placement interest and experience on student responses. Despite the placement's short time frame and lack of opportunity for in-depth comprehensive training in zoological medicine, students reported that the placement had a positive educational impact. More than 90% of students stated that their understanding about modern zoos was good or excellent at the end of the placement (compared with 35.0% before the placement), and 43.0% reported that the placement had a positive impact on their attitudes toward zoos. Students self-reported an increased understanding of the work of zoo clinicians, and there was a highly significant positive change in the students' reported opinions regarding wildlife conservation in general. We provide preliminary evidence to suggest that even short-duration but immersive zoo-based practical training has positive educational value for veterinary students.

Periodontal health, neutrophil activity and cardiovascular health in captive chimpanzees.

OBJECTIVE: To investigate the association of dental and cardiac disease in a cohort of captive chimpanzees DESIGN: 12 captive chimpanzees underwent periodontal and cardiac examinations under anaesthesia during a relocation to a new enclosure. Blood samples were taken for analysis of circulating markers of cardiac health, nutritional status and isolation of neutrophils for functional assays. They were then observed for three years for signs of heart disease. RESULTS: Although the chimpanzees displayed large quantities of supragingival plaque, they had low bleeding scores. Peripheral blood neutrophils responded to innate and adaptive immune stimuli. In the follow up period two animals died and post mortem confirmed heart disease. Levels of NT-proBNP were found to be high in chimpanzees that died from heart disease. CONCLUSIONS: Whilst there appeared to be a correlation between probing depth and age, there appeared to be no correlation between dental data and heart data in this cohort.

Avian anaesthesia related mortality and the associated risk factors in a UK zoological collection.

OBJECTIVE: To analyse avian anaesthesia-related mortality in a UK zoological collection over a 5-year period and identify risk factors for mortality. STUDY DESIGN: Retrospective cohort study. ANIMALS: A total of 135 individual birds across 37 species, anaesthetized during 206 events in a UK zoological collection between 1 January 2014 and 30 June 2019 (inclusive). METHODS: Anaesthesia records were reviewed and variables such as age, body condition, weight, sex, duration of anaesthesia and health status were collated. Anaesthesia-related mortality was defined as those deaths occurring during anaesthesia and up to 7 days postanaesthesia. Outcome was analysed using multivariable conditional logistic regression. Overall mortality was defined and included birds euthanised during anaesthesia for non-anaesthesia related reasons. Data were summarised as median (range). A value of p < 0.05 was considered significant. Relative risks and 95% confidence intervals (95% CI) were calculated for the association between risk factors and anaesthetic death where a statistically significant difference was found. RESULTS: The overall mortality rate was 10.19% (95% CI = 6.06-14.3%), while anaesthesia-related mortality was 3.88% (95% CI = 1.69-7.51%). Birds with an abnormal health status had a 15.53-fold (95% CI = 1.95-123.63) increased risk of death compared with those with a normal health status. The duration of anaesthesia was also a statistically significant risk factor (p = 0.021) in the univariable analysis, but not when combined with health status. No other variables were associated with anaesthesia-related mortality. CONCLUSIONS AND CLINICAL RELEVANCE: Abnormal health status and longer anaesthetic procedures were associated with a significantly increased risk of anaesthesia-related death in this population of birds. It is recommended that anaesthetic duration is minimized, and pre-existing diseases are diagnosed where possible prior to general anaesthesia of birds. Anaesthetizing healthy birds was associated with a low risk of mortality.

Evaluation of the agreement of two oscillometric blood pressure devices with invasive blood pressure in anaesthetized chimpanzees (Pan troglodytes).

OBJECTIVE: To evaluate the agreement of two noninvasive blood pressure devices: a human device with the cuff placed on the wrist (Omron R1) and a veterinary device with the cuff placed on the upper brachium (Surgivet Advisor Vital Signs Monitor) with invasive blood pressure (IBP) measurement in anaesthetized chimpanzees. STUDY DESIGN: Prospective clinical study. ANIMALS: A convenience sample of 11 adult chimpanzees undergoing anaesthesia for translocation and routine health checks. METHODS: Systolic (SAP) and diastolic arterial pressures (DAP) were continuously recorded via a transducer connected to a femoral artery cannula, and at 5 minute intervals from the two oscillometric devices. Agreement was explored using Bland-Altman analysis and bias defined as the mean difference between the two measurement methods. Spearman correlation coefficients were calculated. Significance was set at p < 0.05. RESULTS: Bias and standard deviation for the Surgivet compared with IBP were 8.6 ± 18 for SAP and 8.4 ± 9.9 for DAP, showing a significant underestimation of both variables. Limits of agreement (LOA) were from -27 to 44 for SAP and from -11 to 28 for DAP. Correlation coefficients between the Surgivet and IBP values were 0.86 for SAP and 0.85 for DAP (p < 0.0001). Bias and standard deviation for the Omron compared with the IBP were -21 ± 25 for SAP and -18 ± 15 for DAP, showing a significant overestimation of both variables. LOA were from -70 to -28 for SAP and from -47 to 11 for DAP. Spearman correlation coefficients between the Omron and IBP values were 0.64 for SAP and 0.72 for DAP (p < 0.0001). CONCLUSIONS AND CLINICAL RELEVANCE: Although neither device met all the criteria for device validation, the Surgivet presented better agreement with IBP values than the Omron in adult anaesthetized chimpanzees.

PHYSIOLOGICAL AND ANESTHETIC EFFECTS OF HAND INJECTION VERSUS DARTING TO INDUCE ANESTHESIA IN CHIMPANZEES (PAN TROGLODYTES).

Great ape anesthesia is reported to carry a significant risk. Therefore, techniques aiming to reduce stress and increase welfare, such as hand injection of anesthesia induction agents, have received considerable attention in zoo, laboratory, and captive wildlife environments. However, there is little evidence to support the superiority of such techniques. To investigate this issue, anesthesia records of healthy zoo-housed chimpanzees (Pan troglodytes) between 2012 and 2017 in which the animal was either darted or hand injected were analyzed (n = 50). Sex, age, induction, muscle relaxation, and overall anesthesia quality as well as recovery ratings, heart rate, systolic, mean and diastolic blood pressure, respiratory rate, end-tidal CO2, oxygen saturation (SpO2), and body temperature were analyzed. Chimpanzees that were darted showed statistically significantly higher heart rate, SpO2, and body temperature than those that were hand injected. It was found that darted chimpanzees were also significantly more likely to have poorer perianesthetic muscle relaxation and overall anesthesia rating scores. This study provides further evidence that the use of hand injection can reduce factors associated with stress and improve the quality of chimpanzee anesthesia.

An Exploration of the Value of Elective Health Checks in UK Zoo-Housed Gibbons.

Elective health checks form an important part of the preventative healthcare of many zoo-housed animals. These procedures are not without risk or financial expenditure, meaning careful cost-benefit analysis is required when determining the frequency and intensity with which they are implemented. This study evaluated the value of elective health checks (n = 74) carried out on 33 gibbons at a single UK zoological collection from 2011 to 2018. Data were categorised by health check type, animal age, clinical findings and outcome. Univariable binary logistic regression and multivariable modelling were used to identify factors associated with the likelihood of actionable (clinically significant) outcomes. In total, 51.35% of all elective health checks resulted in an actionable outcome. Elderly heath checks had 13.64 times greater odds of an actionable outcome and 34 times greater odds of a significant radiographic finding, when compared to routine (non-elderly) health checks. Our findings suggest that 75% wild longevity is a suitable threshold for identifying elderly captive gibbons and increasing health check frequency. Whilst further work is needed to ascertain whether these findings can be extrapolated to other collections and/or species, this study demonstrates how the analysis of clinical data can aid in the implementation of an effective and evidence-based preventative healthcare plan.

Discovery of os cordis in the cardiac skeleton of chimpanzees (Pan troglodytes).

Cardiovascular diseases, especially idiopathic myocardial fibrosis, is one of the most significant causes of morbidity and mortality in captive great apes. This study compared the structure and morphology of 16 hearts from chimpanzees (Pan troglodytes) which were either healthy or affected by myocardial fibrosis using X-ray microtomography. In four hearts, a single, hyperdense structure was detected within the right fibrous trigone of the cardiac skeleton. High resolution scans and histopathology revealed trabecular bones in two cases, hyaline cartilage in another case and a focus of mineralised fibro-cartilaginous metaplasia with endochondral ossification in the last case. Four other animals presented with multiple foci of ectopic calcification within the walls of the great vessels. All hearts affected by marked myocardial fibrosis presented with bone or cartilage formation, and increased collagen levels in tissues adjacent to the bone/cartilage, while unaffected hearts did not present with os cordis or cartilago cordis. The presence of an os cordis has been described in some ruminants, camelids, and otters, but never in great apes. This novel research indicates that an os cordis and cartilago cordis is present in some chimpanzees, particularly those affected by myocardial fibrosis, and could influence the risk of cardiac arrhythmias and sudden death.

Comparison of 25-hydroxyvitamin D concentration in chimpanzee dried blood spots and serum.

BACKGROUND: Dried blood spots (DBS) are used in human medicine to measure total 25-hydroxyvitamin D (25-OHD) in the blood. However, this easy and affordable sampling technique has not been evaluated in primates to measure vitamin D concentrations. OBJECTIVES: We aimed to compare 25-OHD measurements in chimpanzee serum at two different laboratories and determine the precision and accuracy of the DBS method by comparing DBS and serum results. METHODS: Blood samples from 17 captive chimpanzees were collected, and 25-OHD3 and 25-OHD2 were measured in serum at two accredited laboratories using liquid chromatography-tandem mass spectrometry. The same analytes were measured on DBS cards, and results were compared with that of serum. Data were assessed using the Spearman correlation, Deming regression, and Bland-Altman analyses. RESULTS: The correlation coefficient between the two measurements in serum was rs  = .51 (P = .04), and the mean bias was -1.25 ± 14.83. When comparing 25-OHD concentrations measured in DBS and serum at the same laboratory, the rs was 0.7 (P = .002), and the mean bias was 1.42 ± 14.58. Estimated intra-assay and inter-assay coefficients of variation for DBS results were 6% and 12.6%, respectively. CONCLUSIONS: Although substantial analytical variability was found in 25-OHD measurements regardless of the sample type, the identification of both constant and proportional error and wider limits of agreement with the DBS technique makes the interpretation of DBS results challenging, especially for values close to clinical cut-off points. The DBS and serum methods were not interchangeable, and further studies are needed to validate DBS samples for vitamin D measurements in chimpanzees.

DIFFUSE IDIOPATHIC SKELETAL HYPEROSTOSIS IN CAPTIVE GORILLAS (GORILLA SPP.): APPEARANCES AND DIAGNOSIS.

Diffuse idiopathic skeletal hyperostosis (DISH) is a disorder of unknown cause, in which new bone forms in soft tissues attached to the skeleton. Originally described in humans, in whom it is quite common, it is usually asymptomatic. New bone may completely bridge across joints, especially in the spine. However, it can be difficult to distinguish from diseases such as spondyloarthritis and spondylosis. With safer and increased use of radiography in diagnosis, the unfamiliar skeletal changes of asymptomatic DISH may now be coincidentally revealed during investigation of other disorders and result in misdiagnosis and unnecessary treatment. There have been case reports of its occurrence in great apes, but this is the first study to illustrate its appearances in a series of 11 skeletons of western and eastern lowland gorillas (Gorilla gorilla gorilla and Gorilla beringei graueri) from zoos in Europe and the United States. The study combines a review of available clinical and postmortem records with examination of the skeletons and radiologic investigation, such as computed tomography (CT). The results indicate that the disorder is probably common in older (>30 yr) captive gorillas, but that it is asymptomatic. It was not symptomatic during life in any of these animals. Several cases had unexpected features, such as extensive involvement of the thorax and extra-articular sacroiliac and tibiofibular joint fusions that are not typical in humans. By illustrating these skeletons, the study should aid differentiation of DISH from spondylosis (syn spondylosis deformans) and spondyloarhritis. It illustrates those features that are atypical of human DISH. CT scanning is valuable in such cases for examining diagnostically important areas such as sacroiliac joints. Increased awareness of DISH should help with understanding its cause, both in gorillas and humans.

Idiopathic Myocardial Fibrosis in Captive Chimpanzees (Pan troglodytes).

Cardiovascular disorders and predominantly idiopathic myocardial fibrosis are frequently associated with mortality among zoo-housed chimpanzees (Pan troglodytes). Formalin-fixed whole hearts of deceased chimpanzees housed in zoos (n = 33) and an African sanctuary (n = 2) underwent detailed macroscopic and histopathologic examination using a standardized protocol. Archived histological slides from the hearts of 23 additional African sanctuary-housed chimpanzees were also examined. Myocardial fibrosis (MF) was identified in 30 of 33 (91%) of the zoo-housed chimpanzees but none of the 25 sanctuary-housed chimpanzees. MF was shown to be characterized by both interstitial and replacement fibrosis. Immunophenotyping demonstrated that the fibrotic lesions were accompanied by the increased presence of macrophages, alpha smooth muscle actin-positive myofibroblasts, and a minimal to mild T-cell-dominant leukocyte infiltration. There was no convincing evidence of cardiotropic viral infection or suggestion that diabetes mellitus or vitamin E or selenium deficiency were associated with the presence of the lesion. However, serum vitamin D concentrations among zoo-housed chimpanzees were found to be lower in seasons of low ultraviolet light levels.

MEDIASTINAL LYMPHOMA AND CHYLOTHORAX IN A STRIPED SKUNK (MEPHITIS MEPHITIS).

Tumors are infrequently reported in skunks, with only a few case reports published in the literature. Chylothorax associated with mediastinal lymphoma was diagnosed in a captive 7-yr-old male striped skunk ( Mephitis mephitis ). The animal presented with anorexia and apathy. Supportive care and prednisolone improved the animal's clinical status for 2 wk preceding its death. Histopathology supported the clinical findings, and the tumor was classified as a mediastinal non-Hodgkin lymphoma, stage 2b, which has not been documented in the literature.

Urolithiasis in a captive group of Tammar wallabies (Macropus eugenii).

Urolithiasis is a well-known disease of the urogenital system in domestic animals, and it has also been described in captive and free-ranging wildlife. This article reports 15 cases of urolithiasis in a captive group of Tammar wallabies (Macropus eugenii) between 2004 and 2011. The analyzed stones were composed of pure calcium carbonate (n = 5), calcium carbonate with traces of calcium phosphate (n = 6), carbonate apatite (n = 2), and carbonate apatite mixed with calcium oxalate (n = 2). In 12 out of 15 cases uroliths were situated only in the renal pelvis; in two cases they were found in the renal pelvis and the ureter; while in one case in the ureter only. No common infectious agents were identified either by microbiological or histopathological methods. Although the exact cause remains unknown, the repetitive occurrence of calcium carbonate urolithiasis suggests husbandry-related causes. To the best of the authors' knowledge, this is the first report on recurrent appearance of urolithiasis in a captive group of Tammar wallabies.

Osteoblastic osteosarcoma in a Grey Mouse Lemur (Microcebus murinus) - short communication.

The Grey Mouse Lemur (Microcebus murinus) is a nocturnal lemur species that lives only in Madagascar. It is one of the most abundant lemur species and its native populations are not endangered, but animals belonging to this species are rarely exhibited in zoos. While tumours are quite frequently described in other primates, there are very few publications about neoplasia in lemurs. In this case report we describe a mandibular osteoblastic osteosarcoma in a Grey Mouse Lemur (Microcebus murinus). To the best of the authors' knowledge, this is the first scientific article describing osteosarcoma in a prosimian and also reporting a tumour in the mandible in this taxon.

Novel adenoviruses and herpesviruses detected in bats.

Samples from native Hungarian or captive bats were tested by PCR for the presence of adenoviruses and herpesviruses. Two novel adenoviruses from a common noctule (Nyctalus noctula) and a greater horseshoe (Rhinolophus ferrum-equinum) bat were detected. In captive Egyptian fruit bats (Rousettus aegyptiacus), DNA from two novel herpesviruses was demonstrated. Phylogenetic analysis facilitated provisional taxonomic placement of the newly detected viruses. Such analysis and the existence of unique, shared early proteins (E3 and E4) suggest that canine adenoviruses may have originated in vespertilinoid bats.

Detection of a novel bat gammaherpesvirus in Hungary.

This paper describes the detection of a novel herpesvirus in a Serotine bat (Eptesicus serotinus) in Hungary. The rescued animal showed signs of icterus and anorexia and died within a day, in spite of immediate supportive therapy. Autopsy confirmed the clinical picture by the major lesions observed in the liver. Histopathology revealed vacuolar degeneration in the hepatocytes and leukocytosis in the sinusoidal lumina. By electron microscopy, hydropic degeneration and apoptotic cells with a pycnotic nucleus were found in the liver. Bacteriological examinations gave negative results. As part of a routine screening project, detection of adeno- and herpesviruses from homogenised samples of the liver, lungs and small intestines was attempted by nested polymerase chain reaction (PCR) assays. The adenovirus PCR ended with negative results. The herpesvirus PCR resulted in an amplification product of specific size. The nucleotide sequence of the amplicon was determined and analysed by homology search and phylogenetic analysis. A novel herpesvirus was identified, which seemed to be most closely related to members of the genus Rhadinovirus within the subfamily Gammaherpesvirinae. The causative role of the detected rhadinovirus in the fatal condition of the Serotine bat could not be proven, but it is most likely that reactivation from a latent infection allowed the detection of the virus by PCR.