Somatic mutation rates scale with lifespan across mammals.

The rates and patterns of somatic mutation in normal tissues are largely unknown outside of humans1-7. Comparative analyses can shed light on the diversity of mutagenesis across species, and on long-standing hypotheses about the evolution of somatic mutation rates and their role in cancer and ageing. Here we performed whole-genome sequencing of 208 intestinal crypts from 56 individuals to study the landscape of somatic mutation across 16 mammalian species. We found that somatic mutagenesis was dominated by seemingly endogenous mutational processes in all species, including 5-methylcytosine deamination and oxidative damage. With some differences, mutational signatures in other species resembled those described in humans8, although the relative contribution of each signature varied across species. Notably, the somatic mutation rate per year varied greatly across species and exhibited a strong inverse relationship with species lifespan, with no other life-history trait studied showing a comparable association. Despite widely different life histories among the species we examined-including variation of around 30-fold in lifespan and around 40,000-fold in body mass-the somatic mutation burden at the end of lifespan varied only by a factor of around 3. These data unveil common mutational processes across mammals, and suggest that somatic mutation rates are evolutionarily constrained and may be a contributing factor in ageing.

FIVE YEARS OF PARTULA SNAIL PRE-EXPORT HEALTH SCREENING.

Between 2015 and 2019, a health screening was carried out annually on captive-bred Partula snails prior to export for reintroduction as part of an international effort to repopulate areas of French Polynesia, where the snails were extinct or critically endangered. In total, 129 separate tank populations of 12 different species were screened at ZSL London Zoo. Wet mounts and smears stained with modified Ziehl-Neelsen (MZN) of 535 fecal samples were examined, and 45% contained flagellated protozoa, and 35.5% had MZN-positive oocysts, measuring 3-5 µm in diameter. Smaller (2 µm) presumptive spores, MZN-positive bacilli, ciliated protozoa and nematodes were recorded less frequently. Fecal bacterial culture yielded mixed species, with a clear predominance of Myroides species (88.9% of samples). The MZN-positive oocysts (3-5 µm) were present in 6.5% of impression smears from the apices of 432 snails examined postmortem, plus acid-fast bacilli in a few cases, but no 2 µm spores. Mixed bacteria were cultured from coelomic swabs, with Myroides species again the most common (63.5%). Histologic examination was carried out on 292 snails. Autolysis affected almost 90% of those found dead but only 3.4% of euthanized snails. Histology commonly identified microsporidial sporocysts in the digestive gland and midgut epithelium of all but two species. Intracellular, extracytoplasmic Cryptosporidium-like organisms were also common in the midgut but were only observed when snails were fixed in 10% formalin (2017-2019), not ethanol. There were no clear pathologic changes associated with either organism. Pigmented hemocytic nodules were commonly observed, most frequently in the foot process; these were either age related or evidence of prior chronic inflammatory reaction and of low clinical significance. With no evidence of poor health and no significant organisms found, a total of 4,978 individuals representing 12 species were exported for reintroduction.

DEVELOPMENT AND EVALUATION OF A STANDARDIZED SYSTEM FOR THE ASSESSMENT OF LOCOMOTOR HEALTH IN ELEPHANTS UNDER HUMAN CARE.

Although lameness is a common problem in elephants (Asian elephant [Elephas maximus] and African elephants Loxodonta africana and Loxodonta cyclotis) under human care, there has not been a standardized lameness assessment system to date. This study developed and evaluated a standardized system for the assessment of locomotion in elephants under human care regardless of husbandry system. In total, 72 elephants out of a possible 73 in the United Kingdom and Ireland were filmed from behind, from in front, and from both sides. Using a questionnaire and a select panel of elephant specialists, a zoo veterinarian, and a locomotion expert, a numerical rating scoring (NRS) system was proposed. Locomotion was scored on a 4-point scale with numerical values 0-4 corresponding to specific criteria as follows: 0 = clinically sound, 1 = stiffness, 2 = abnormal tracking, and 4 = reluctance to bear weight. The intra- and interobserver repeatability of five veterinary surgeons using this system was determined and compared with a visual analog scale (VAS) expressed as a 100-mm line. Overall intraobserver reliability was moderate (Cohen's kappa [κ] = 0.676) and interobserver reliability was fair (κ = 0.37) for the presence of lameness. Interobserver agreement improved from the first scoring to second scoring from slight agreement to fair agreement for stiffness and reluctance to bear weight. Abnormal tracking had moderate intraobserver agreement for both scoring sessions. There were wide widths of agreement for the VAS interobserver (67 mm); however, they were narrower for the intraobserver (33 mm). The developed NRS can be used on freely moving elephants to evaluate elephant locomotion, regardless of husbandry methods, and has been shown to be more reliable than a VAS.

Detection of Usutu virus infection in wild birds in the United Kingdom, 2020.

In August 2020, as part of a long-term disease surveillance programme, Usutu virus was detected in five Eurasian blackbirds (Turdus merula) and one house sparrow (Passer domesticus) from Greater London, England. This was initially detected by reverse transcription-PCR and was confirmed by virus isolation and by immunohistochemical detection of flavivirus in tissues. Phylogenetic analysis identified Usutu virus African 3.2 lineage, which is prevalent in the Netherlands and Belgium, suggesting a potential incursion from mainland Europe.

MYCOBACTERIAL DISEASE AND SUBSEQUENT DIAGNOSTIC INVESTIGATIONS IN A GROUP OF CAPTIVE PINNIPEDS IN NEW ZEALAND.

This case series includes a single case of disseminated tuberculous disease due to Mycobacterium pinnipedii in a New Zealand fur seal (Arctocephalus forsteri), which was being cared for by a zoo in New Zealand. The remaining five pinnipeds in the colony underwent extensive mycobacterial disease surveillance over the following 4 yr, involving a total of 26 anesthetic procedures and numerous diagnostic tests that included comparative intradermal tuberculin skin tests, mycobacterial antibody serology, respiratory and gastric lavages, and computed tomography (CT) scans. An additional case of chronic sinusitis due to Mycobacterium marinum and Pseudomonas aeruginosa was identified in a California sea lion (Zalophus californianus). Results from CT and the respiratory lavages were the most helpful antemortem diagnostic tests for active mycobacterial disease in this case series. Of the remaining four animals, two were euthanatized and two remain alive, and none of them had evidence of active mycobacterial disease. Further mycobacterial disease surveillance in staff and animals was performed, and no other case was identified. There are no validated mycobacterial surveillance tests available for pinnipeds and so it remains unknown whether the two surviving pinnipeds are truly negative or whether they have latent mycobacterial infection that could develop into active mycobacterial disease in the future. For this reason, increased levels of biosecurity and quarantine remain permanently in place for the pinniped colony.

POSTMORTEM FINDINGS IN EIGHT SPECIES OF CAPTIVE CAECILIAN (AMPHIBIA: GYMNOPHIONA) OVER A TEN-YEAR PERIOD.

Between July 2007 and June 2017 there were 86 deaths in the populations of eight caecilian species at the Zoological Society of London (ZSL) London Zoo. The mortality rate (deaths per animal-year at risk) ranged from 0.03 in the Congo caecilian (Herpele squalostoma) to 0.85 in Kaup's caecilian (Potomotyphlus kaupii). Among the 73 individuals examined post mortem, no cause of death or primary diagnosis could be established in 35 cases, but of the others the most common cause of death was dermatitis (22 cases). When all significant pathological findings were considered, skin lesions of varying types were again the commonest (56 cases), particularly among the aquatic species: Typhlonectes compressicauda (18 out of 21 cases), T. natans (8/10) and P. kaupii (12/14). Other common findings were poor gut-fill (35 cases), kidney and gastrointestinal lesions (10 cases each), generalized congestion (8 cases) and poor body condition (6 cases). This review adds to the growing body of knowledge regarding the presentations and causes of disease in captive caecilians.

FERLAVIRUS-RELATED DEATHS IN A COLLECTION OF VIPERID SNAKES.

Between June and October 2013, 26 snakes of six viperid species kept in two adjoining rooms died ( n = 16) or were euthanized on medical (1) or welfare grounds (9). Two were from the main zoo collection, but the other 24 had been imported and quarantined for a minimum of 6 mo. Four of those that died and the single snake euthanized on medical grounds showed minor signs of respiratory disease prior to death, and five were weak, lethargic, and/or poor feeders. Frequent postmortem findings among all snakes were poor body condition (18) and respiratory disease (13). Seventeen cases were examined histologically, and pneumonia, sometimes with air sacculitis and/or tracheitis, was present in 15 individuals. Lung samples from 24 snakes were ferlavirus polymerase chain reaction (PCR) positive, and one of the two snakes for which only liver was available was also positive. The negative liver sample was from a snake that died of sepsis following anesthesia for surgical removal of a spindle cell sarcoma. Correlation with antemortem PCR testing of glottal and cloacal swabs in five cases was poor (sensitivity = 40%). Immunohistochemistry (IHC) for ferlaviruses on the tissues of 13 PCR-positive cases showed positive labeling in 7 only. Tissues samples from 22 ferlavirus PCR-positive snakes were examined for Chlamydia species by PCR, and 9 were positive, although DNA sequencing only confirmed two of three tested as Chlamydia pneumoniae. Immunohistochemistry for Chlamydia pneumoniae of seven cases (two Chlamydiales PCR positive, one of which was sequenced as C. pneumoniae, plus five negative) confirmed the Chlamydia PCR results. These two Chlamydiales PCR and IHC positive snakes were ferlavirus PCR positive, but IHC negative suggesting that, even though a ferlavirus was the predominant cause of the outbreak, in a few cases death may have been due to chlamydiosis with ferlavirus present, but not acting as the primary pathogen.

Retrospective study of mortality in Asiatic lions (Panthera leo persica) in the European breeding population between 2000 and 2014.

Although the European population of Asiatic lions (Panthera leo persica) has been managed under the European Endangered Species Program (EEP) since 1990, little is known about the health status of the population. This study was designed to characterize mortality for this population through examination of the studbook and other records on 392 Asiatic lions living in the EEP between 2000 and 2014. A total of 270 animals died during the period with 80% of them being under 1 year old. The mortality rate for under 1 year olds was 54%, while the odds of survival of cubs within a litter increased if the dam had had litters previously. Survival to reproductive age was 44%. Post-mortem reports were requested and the cause of death was obtained for 133 animals. Trauma inflicted by a conspecific and lack of care were common causes of death (26% and 22%, respectively) and were also responsible for most of the neonatal mortalities. Congenital defects were responsible for 9% of deaths, although the true prevalence is likely underestimated. A common necropsy protocol for all Asiatic lion collections is needed to facilitate future studies. Zoo Biol. 36:66-73, 2017. © 2017 Wiley Periodicals, Inc.

THE IMPACT OF ELEPHANT ENDOTHELIOTROPIC HERPESVIRUS ON THE CAPTIVE ASIAN ELEPHANT (ELEPHAS MAXIMUS) POPULATION OF THE UNITED KINGDOM AND IRELAND (1995-2013).

Elephant endotheliotropic herpesvirus (EEHV) is one of the most devastating infections and causes of mortality in captive Asian elephant ( Elephas maximus ) populations. Eight confirmed fatal EEHV cases have occurred since 1995 within the captive Asian elephant population of the United Kingdom and Ireland. This report aims to review the impact of EEHV on the captive Asian elephant population in the United Kingdom and Ireland, document and compare fatal cases, and recommend a framework of monitoring within the United Kingdom and Ireland to increase the success of treatment of EEHV hemorrhagic disease (EEHV HD) in the future. Six zoologic institutions (which include zoos, safari parks, and wildlife parks) that currently house or have previously housed a captive Asian elephant group were included in this report. Medical records and postmortem results were collected from four of these institutions for each confirmed fatal case. EEHV HD was found to be responsible for 29.6% of fatalities in Asian elephants born in captivity in the United Kingdom and Ireland between 1995 and 2013. Following a review of all the cases, it is shown that although clinical signs may be associated with specific EEHV species, the swiftness of disease progression means that most body tissues are impacted 1-6 days following the presentation of visible clinical signs and treatment is less likely to succeed. Therefore, EEHV monitoring should consist of conducting regular polymerase chain reaction analysis of whole blood samples from at-risk, young Asian elephants aged 1-8 yr in order for subclinical viremia to be identified early and treatment to be started before the appearance of visible clinical signs.

A novel antigen capture ELISA for the specific detection of IgG antibodies to elephant endotheliotropic herpes virus.

BACKGROUND: Elephants are classified as critically endangered animals by the International Union for Conservation of Species (IUCN). Elephant endotheliotropic herpesvirus (EEHV) poses a large threat to breeding programs of captive Asian elephants by causing fatal haemorrhagic disease. EEHV infection is detected by PCR in samples from both clinically ill and asymptomatic elephants with an active infection, whereas latent carriers can be distinguished exclusively via serological assays. To date, identification of latent carriers has been challenging, since there are no serological assays capable of detecting seropositive elephants. RESULTS: Here we describe a novel ELISA that specifically detects EEHV antibodies circulating in Asian elephant plasma/serum. Approximately 80 % of PCR positive elephants display EEHV-specific antibodies. Monitoring three Asian elephant herds from European zoos revealed that the serostatus of elephants within a herd varied from non-detectable to high titers. The antibody titers showed typical herpes-like rise-and-fall patterns in time which occur in all seropositive animals in the herd more or less simultaneously. CONCLUSIONS: This study shows that the developed ELISA is suitable to detect antibodies specific to EEHV. It allows study of EEHV seroprevalence in Asian elephants. Results confirm that EEHV prevalence among Asian elephants (whether captive-born or wild-caught) is high.

Longitudinal Improvements in Zoo-Housed Elephant Welfare: A Case Study at ZSL Whipsnade Zoo.

Over the last two decades, criticisms were raised regarding the welfare experienced by elephants in European and North American zoos. Concerns regarding the welfare of zoo-housed elephants in the UK and Europe were consolidated in the publication of several key reports, and media interest peaked. Throughout this study we aim to outline the behavioural measures of welfare observed in the current group of Asian elephants (Elephas maximus) at Zoological Society of London (ZSL) Whipsnade Zoo, using key welfare indicators for this species and comparing them to previous published work. Following the instigation of a species-specific research programme, empirical behavioural data were available to quantify any developments in care and welfare. The collection of behavioural information revealed that individuals in our study group engage in low levels of stereotypic behaviour, have formed and maintain strong associations with one another and display a high proportion of engagement in lying rest. We outline that by applying simple, low-cost methods of behavioural data collection and analysis, it is possible to collect evidence that allows us to evaluate individual level welfare. This facilitates the adoption of an evidence-based approach to zoo management as well as demonstrating compliance with updated legislation for this species.

Successful management of Heinz body hemolytic anemia associated with leek (Allium ampeloprasum) ingestion in a South American coati (Nasua nasua).

OBJECTIVE: To describe the diagnosis, management, and outcome of Heinz body hemolytic anemia in a South American coati (Nasua nasua) secondary to suspected leek (Allium ampeloprasum) toxicosis. CASE SUMMARY: A South American coati presented with Heinz body hemolytic anemia following addition of leeks to its diet for 2-5 days prior to initial presentation. Administration of a whole blood transfusion from an animal of the same species (conspecific) and supportive care resulted in immediate improvement in clinical signs. Normal behavior fully returned within 6 days of transfusion. Hematological evidence of anemia resolved by 4 weeks and there were no significant features of oxidative injury present by 8 weeks following initial presentation. NEW INFORMATION PROVIDED: This is the first reported case of Heinz body hemolytic anemia, suspected leek toxicosis, and administration of a blood transfusion in this species.

Isolation and characterisation of Vibrio cholerae from fish examined postmortem at ZSL London Zoo between 2014 and 2018.

BACKGROUND: When suspect Vibrio cholerae were cultured from fish at ZSL London Zoo, investigations were carried out to determine whether they were possible causes of cholera. METHODS: Bacterial culture was carried out on fish examined postmortem and colonies were identified using standard techniques including the API 20NE biochemical test kits. Suspect isolates were submitted to the Public Health England laboratory for additional testing. Separately, a number of fish were submitted for routine histopathology. RESULTS: On 13 occasions between 2014 and 2018, suspected V cholerae were cultured from individuals of eight different freshwater fish species. Archived cultures for eight of these (from six different fish species) were investigated and seven isolates (from five fish species) were confirmed as V cholerae, but all were non-O1, non-O139 strains. Whole-genome sequencing showed that the five fish species had unique V cholerae multilocus sequence types (three isolates from Aphanius danfordii were identical), all of which were genetically distant from human isolates. CONCLUSIONS: There was no evidence that these isolates could cause cholera. Histopathological changes consistent with vibriosis were seen in several fish, suggesting that V cholerae were causing the disease, but there were also concurrent infections or predisposing stress factors.

Culicoides species composition and molecular identification of host blood meals at two zoos in the UK.

BACKGROUND: Culicoides biting midges are biological vectors of arboviruses including bluetongue virus (BTV), Schmallenberg virus (SBV) and African horse sickness virus (AHSV). Zoos are home to a wide range of 'at risk' exotic and native species of animals. These animals have a high value both in monetary terms, conservation significance and breeding potential. To understand the risk these viruses pose to zoo animals, it is necessary to characterise the Culicoides fauna at zoos and determine which potential vector species are feeding on which hosts. METHODS: Light-suction traps were used at two UK zoos: the Zoological Society of London (ZSL) London Zoo (LZ) and ZSL Whipsnade Zoo (WZ). Traps were run one night each week from June 2014 to June 2015. Culicoides were morphologically identified to the species level and any blood-fed Culicoides were processed for blood-meal analysis. DNA from blood meals was extracted and amplified using previously published primers. Sequencing was then carried out to determine the host species. RESULTS: A total of 11,648 Culicoides were trapped and identified (n = 5880 from ZSL WZ; n = 5768 from ZSL LZ), constituting 25 different species. The six putative vectors of BTV, SBV and AHSV in northern Europe were found at both zoos and made up the majority of the total catch (n = 10,701). A total of 31 host sequences were obtained from blood-fed Culicoides. Culicoides obsoletus/C. scoticus, Culicoides dewulfi, Culicoides parroti and Culicoides punctatus were found to be biting a wide range of mammals including Bactrian camels, Indian rhinoceros, Asian elephants and humans, with Culicoides obsoletus/C. scoticus also biting Darwin's rhea. The bird-biting species, Culicoides achrayi, was found to be feeding on blackbirds, blue tits, magpies and carrion crows. CONCLUSIONS: To our knowledge, this is the first study to directly confirm blood-feeding of Culicoides on exotic zoo animals in the UK and shows that they are able to utilise a wide range of exotic as well as native host species. Due to the susceptibility of some zoo animals to Culicoides-borne arboviruses, this study demonstrates that in the event of an outbreak of one of these viruses in the UK, preventative and mitigating measures would need to be taken.