Oral cavity squamous cell carcinomas in zoo-managed Goeldi's monkeys (Callimico goeldii).

BACKGROUND: Oral cavity squamous cell carcinomas (OCSCCs) are relatively common in multiple non-human primate species but are poorly documented in Goeldi's monkeys. METHODS: Four Goeldi's monkeys with OCSCC, from three zoological collections, underwent necropsy with cytology, histopathology, immunohistochemistry, and pan-herpesvirus PCR analysis. RESULTS: All animals were euthanised and exhibited poor-to-emaciated body condition. Three OCSCCs arose from the maxillary oral mucosa and a single OCSCC was primarily mandibular, with bone invasion evident in three cases. Histologically, one OCSCC in situ was diagnosed, whilst the rest were typically invasive OCSCCs. Neoplastic cells were immunopositive for pancytokeratin and E-cadherin. All examined cases were negative for regional lymph node (RLN) and/or distant metastases, cyclooxygenase-2 (COX-2) immunoexpression, and panherpesvirus PCR expression. CONCLUSIONS: OCSCCs in Goeldi's monkeys may be deeply invasive, but not readily metastatic. No herpesvirus-association or COX-2 expression was evident; the latter suggesting that NSAIDs are unlikely to be a viable chemotherapeutic treatment.

Cutaneous apocrine gland neoplasia in 16 captive African wild dogs (Lycaon pictus).

This retrospective study documents the occurrence of single and multiple cutaneous apocrine gland tumours (CATs) on the dorsal midline of 16 captive African wild dogs (AWDs, Lycaon pictus) derived from 161 submissions to diagnostic laboratories in South Africa, France and Germany between 1997 and 2022. Animals included in the study came from zoological institutions in South Africa (n = 2), France (n = 5) and Germany (n = 1) and ranged from 5 to 14 years of age. Fifteen affected animals were female (94%) and one was male. CATs presented as raised, hairless, multilobular, grey firm masses, consistently located along the dorsal midline. Apart from a single cutaneous apocrine adenoma and a cystadenoma occurring concurrently with two non-cystic adenocarcinomas, neoplasms were consistent with malignant cutaneous apocrine adenocarcinomas with lymphatic spread and visceral metastases. Advanced age and female sex were identified as risk factors. A genetic component or association with the increasing use of GnRH agonist contraceptives was suspected but could not be established. This study highlights the need for close clinical monitoring of AWDs over the age of 5 years for the development of CATs along the dorsal midline and supports early surgical intervention. More research is needed to determine the role of inbreeding, endocrine changes and husbandry factors that may play a role in the development of CATs on the dorsal midline of AWDs.

RETROSPECTIVE STUDY OF MORBIDITY AND MORTALITY OF CAPTIVE AFRICAN WILD DOGS (LYCAON PICTUS) HELD WITHIN UNITED KINGDOM ZOOLOGICAL INSTITUTIONS BETWEEN 2000 AND 2020.

The African wild dog (Lycaon pictus) is listed as Endangered by the International Union for Conservation of Nature and is part of captive breeding programs designed to support free-living populations and genetic diversity. This study's aim was to identify common causes of morbidity and mortality objectively in United Kingdom captive African wild dogs to inform management recommendations that will improve health and welfare and reduce disease prevalence. Data were gathered from 140 individual dogs housed in 10 institutions, with morbidity records for 122 individuals and 70 postmortem reports. Descriptive statistics including the Mann-Whitney U test and odds ratios were used to analyze morbidity and mortality across age and sex. The most common cause of death for African wild dogs, excluding those,< 7 d old, was trauma (23%), followed by geriatric (18%), degenerative (15%), and neoplastic (14%) conditions. The most common morbidity was also trauma (62%), of which 76% was caused by intraspecific aggression. Integumentary disease secondary to trauma was the most common morbidity by body system. Eight independent incidents of barbiturate toxicosis from consumption of contaminated carcasses, affecting 18 animals, were identified. Records for neonatal deaths were incomplete and conclusions limited; neonatal loss was estimated at 20.5%. Recommendations include research into factors affecting intraspecific aggression in captivity, operant conditioning for hand injection, provision of dietary carcasses from reputable sources, and improved record-keeping.

RENAL PATHOLOGY IN CAPTIVE ADULT ALAOTRAN GENTLE LEMURS (HAPALEMUR ALAOTRENSIS).

Full medical histories from captive Alaotran gentle lemurs or Bandro (Hapalemur alaotrensis) > 1 yr old that died between 1990 and 2016 were requested from holding institutions. Eighty-six individuals died during the period analyzed. Full postmortem reports were received from 40 (46.5%) animals from 16 different institutions across Europe (15) and North America (1). Eighteen animals (45%) showed azotemia within three months of death, with accompanying histological renal lesions. Another 17 (42.5%) showed histological renal lesions, but no renal function assessment was carried out antemortem, or results were within normal limits. Only five animals (12.5%) showed no renal lesions. Of the 35 (87.5%) animals with histological renal lesions, 18 were females, and 17 were males, 11 were wild caught, and 24 were captive born. Twenty-seven animals were euthanized, seven were found dead, and in one case, no details were provided. Sixty-four blood samples from 22 animals were available. Azotemia was observed on average 407 d antemortem, with a case observed as early as 2,318 d antemortem. Twenty-nine urinalyses from 12 animals were carried out antemortem. All animals showed hematuria or proteinuria in at least one antemortem sample. A pH decrease from 8.5 to 5.0 was observed in two animals antemortem. Gross renal lesions most frequently reported were irregular surface (n = 14), abnormal shape (n = 12), and/or presence of cysts (n = 9). The most common histological lesions were interstitial nephritis (n = 25), interstitial fibrosis (n = 26), tubule dilation (n = 16), and glomerulosclerosis (n = 12). Development of additional diagnostic tools, standardization of ante- and postmortem diagnostic protocols, and further investigation into potential etiologies, such as diets offered in captivity and genetic factors, should be considered as the next steps for the veterinary management of this species in captivity.

A retrospective study of pathologic findings in cephalopods (extant subclasses: Coleoidea and Nautiloidea) under laboratory and aquarium management.

This retrospective study examines pathologic findings in 593 captive cephalopods (340 octopuses, 130 cuttlefish, 33 squid, and 90 nautiluses; 22 species in total) submitted to International Zoo Veterinary Group Pathology between May 2003 and August 2022. Common octopus, European common cuttlefish, hummingbird bobtail squid, and chambered nautilus were the most numerous species from the included orders of Octopoda, Sepiida, Sepiolida, and Nautilida, respectively. Commonly identified conditions included coccidiosis and renal dicyemid mesozoan infection in octopuses, amebiasis in squid, bacterial infections in cuttlefish, and idiopathic multisystemic inflammatory disease in nautiluses. Coccidiosis was most frequent in common octopuses, giant Pacific octopuses, and California 2-spot octopuses (present in 68.4%, 46.3%, and 23.8% of these species, respectively) and was the attributed cause of death in 32.3%, 36.0%, and 60.0% of such cases, respectively. Ulcerative dermatitis (UD) was common, affecting squid, cuttlefish, and octopuses, while many nautiluses exhibited black shell disease and/or UD. Notable differences in the prevalence of UD were detected between laboratory and aquaria-housed decapodiforms; 52.2% for laboratory squid versus 20.0% in aquaria; 51.3% in laboratory cuttlefish versus 11.0% in aquaria. All octopuses and nautiluses in the study were derived from aquaria. Semelparity-associated death in Coleoidea species was identified in 22.4% of octopuses, 11.5% of cuttlefish, and 6.1% of squid. This report aims to provide an overview and reassessment of species-specific disease patterns under aquarium and laboratory management as a starting point for future developments in husbandry and disease investigation.

Cowpox in zoo and wild animals in the United Kingdom.

Cowpox virus is considered to be a re-emerging zoonotic pathogen and a public health threat due to increasing numbers of cases in humans and animals in Europe over the past decade, including within the United Kingdom (UK). We present epidemiological data and diagnostic features of 27 recent, naturally occurring cowpox cases in zoo and wild animals across the UK, including the first reports of cowpox in two snow leopards (Panthera uncia), a Bengal tiger (Panthera tigris tigris), three Chilean pudus (Pudu puda), a Malayan tapir (Tapirus indicus) and a Eurasian otter (Lutra lutra), and the first reports of Orthopoxvirus infection in a lar gibbon (Hylobates lar), a Southern tamandua (Tamandua tetradactyla) and an aardvark (Orycteropus afer). This study provides a detailed overview of cowpox infections in a wide range of non-domestic animal species, presents a range of methods for diagnosis and demonstrates the value of retrospective analysis of pathology surveillance in revealing epidemiological links.

Demodex carolliae in a colony of Seba's short-tailed bats (Carollia perspicillata): clinical, pathological and parasitological findings.

Seba's short-tailed bats (Carollia perspicillata) are a frugivorous species native to Central and South America. Despite their importance as a reservoir for zoonotic pathogens and their popularity in zoological collection and as research models, there are relatively few reports on non-zoonotic diseases of bats. Mites of the genus Demodex are obligate commensals of the skin of a range of mammals, are highly host-specific and are not associated with clinical disease when present in low numbers. However, infestation with high numbers can result in severe or even fatal disease and substantially affect the well-being of the animals. The clinical, pathological and parasitological findings in 12 Seba's short-tailed bats with demodicosis from a colony kept at Munich Zoo Hellabrunn between 1992 and 2021 are described in this report. From 2002, skin lesions became apparent on the head, especially the periocular region, nose and ears, as well as the genital area of some animals. In advanced cases, skin changes were also present on the abdomen, back and extremities. Gross findings typically included alopecia and thickening of the skin, with the formation of papules, reflecting cystically dilated hair follicles containing myriads of demodecid mites. Histologically, lesions were characterized by a paucicellular lymphocytic dermatitis and folliculitis with perifollicular fibrosis, epidermal hyperplasia, orthokeratotic hyperkeratosis and disproportionately high numbers of intrafollicular arthropods. Demodex carolliae was identified morphologically by light, phase-contrast and electron microscopy. Further characterization was achieved by extraction of parasitic DNA and partial gene sequencing of two mitochondrial genes, 16S rDNA and cox1. This is the first clinicopathological description of generalized demodicosis in Seba's short-tailed bats and includes the first molecular characterization of D. carolliae with provision of a GenBank entry.

Case series: Lymphoid neoplasia in three elasmobranch species.

Elasmobranchs (sharks and rays) are charismatic cartilaginous fish, popular in public aquaria. Almost 200 shark and ray species are listed as threatened by the International Union for Conservation of Nature (IUCN), demonstrating the importance of captive breeding and research programmes. Limited studies investigate diseases of elasmobranchs in captive and free-living environments, and among available literature neoplasia is rarely reported, with even fewer cases of lymphoid neoplasia documented. This article outlines the first reports of lymphoid neoplasia in three elasmobranch species in which haematopoietic neoplasms have not been reported to date. It summarizes signalment, history and histopathologic findings in an undulate ray, Raja undulata (Lacepede), a common smooth-hound, Mustelus mustelus (Linnaeus) and a bat ray, Myliobatis californica (Gill). Lesions were confirmed in a wide range of tissues and evidence of lymphoid leukaemia was seen in two cases. This small-scale review demonstrates that lymphoid neoplasia should be considered as a differential diagnosis in elasmobranchs presenting with lethargy and anorexia and highlights the challenges of immunohistochemical work up.

Comparative Study of the Role of Interepithelial Mucosal Mast Cells in the Context of Intestinal Adenoma-Carcinoma Progression.

Mast cells (MCs) are crucial players in the relationship between the tumor microenvironment (TME) and cancer cells and have been shown to influence angiogenesis and progression of human colorectal cancer (CRC). However, the role of MCs in the TME is controversially discussed as either pro- or anti-tumorigenic. Genetically engineered mouse models (GEMMs) are the most frequently used in vivo models for human CRC research. In the murine intestine there are at least three different MC subtypes: interepithelial mucosal mast cells (ieMMCs), lamina proprial mucosal mast cells (lpMMCs) and connective tissue mast cells (CTMCs). Interepithelial mucosal mast cells (ieMMCs) in (pre-)neoplastic intestinal formalin-fixed paraffin-embedded (FFPE) specimens of mouse models (total lesions n = 274) and human patients (n = 104) were immunohistochemically identified and semiquantitatively scored. Scores were analyzed along the adenoma-carcinoma sequence in humans and 12 GEMMs of small and large intestinal cancer. The presence of ieMMCs was a common finding in intestinal adenomas and carcinomas in mice and humans. The number of ieMMCs decreased in the course of colonic adenoma-carcinoma sequence in both species (p < 0.001). However, this dynamic cellular state was not observed for small intestinal murine tumors. Furthermore, ieMMC scores were higher in GEMMs with altered Wnt signaling (active ß-catenin) than in GEMMs with altered MAPK signaling and wildtypes (WT). In conclusion, we hypothesize that, besides stromal MCs (lpMMCs/CTMCs), particularly the ieMMC subset is important for onset and progression of intestinal neoplasia and may interact with the adjacent neoplastic epithelial cells in dependence on the molecular environment. Moreover, our study indicates the need for adequate GEMMs for the investigation of the intestinal immunologic TME.

CHOLELITHIASIS IN CAPTIVE MOUNTAIN CHICKEN FROGS (LEPTODACTYLUS FALLAX): DIAGNOSTIC IMAGING AND HISTOPATHOLOGICAL FEATURES.

The mountain chicken frog (Leptodactylus fallax) is a critically endangered species highly reliant on ex situ conservation programs. In captivity, cholelithiasis has been reported during clinical examinations using diagnostic imaging and observed during postmortem examinations. Some individuals have presented with nonspecific clinical signs potentially associated with this condition, but little is known about its clinical relevance. A retrospective evaluation of ultrasonographic (n = 139) and radiographic (n = 156) images and histopathology samples (n = 32) obtained between 2014 and 2020 from 133 individuals was performed. An ultrasound scoring system was developed to evaluate changes in the gallbladder, with 38% (53/139) of the images showing abnormal contents. Gallbladder distension appeared associated with these findings (generalized estimating equation model, P < 0.001). In contrast, radiography proved to have low overall sensitivity (48%) when compared to ultrasonography for identifying abnormal gallbladder contents. A weak level of agreement (Cohen's kappa = 0.535) was observed between the imaging modalities. Histologically, cholecystitis was present in 86% (12/14) of the individuals, thickening of the gallbladder wall in 71% (10/14), and intrahepatic cholangitis in 90% (18/20). There was no evidence of cholestasis in any of the affected individuals. A significant difference was observed in the hepatic melanomacrophage density between animals with and without cholelithiasis (Welch two-sample t test, P < 0.001). This study provides an overview on the use of diagnostic imaging modalities to evaluate cholelithiasis and proposes a convenient ultrasound score to standardize monitoring of the condition in L. fallax. It is also the first systematic review of histopathological changes associated with cholelithiasis in this species.

Avian Malaria in Penguins: Diagnostics and Future Direction in the Context of Climate Change.

Avian malaria is caused by infection with haemoprotozoa of the genus Plasmodium. Infection is endemic in large parts of the world and is typically subclinical in birds that are native to these regions. Several penguin species have evolved in non-endemic regions without the selective pressure that these parasites exert and are highly susceptible to infection when transplanted to endemic regions, for example, in the context of zoological collections or rehabilitation centers. Avian malaria in penguins typically causes acute mortality without premonitory signs, or less commonly, nonspecific signs of morbidity, followed by mortality. Additionally, infection is reported in wild penguins, though the significance of these infections remains equivocal. As global temperatures continue to increase, avian malaria is likely to pose a continued and further threat to conservation efforts in captive environments. Intra vitam diagnosis currently relies on the evaluation of blood smears and molecular methods. The former is unreliable in penguins, as the acute clinical course typically does not allow the development of parasitemia. This absence of parasitemia also makes speciation challenging. Current molecular methods typically target the Cytochrome B or 18s subunit and have proven variably sensitive and specific. Reliable intra vitam diagnosis of avian malaria and further information about the causative agents at a species level would be very valuable in understanding the epidemiology and likely future course of avian malaria infection in penguins, and in particular, the implications avian malaria may have for conservation efforts. This paper provides an overview of malaria in penguins, discusses its changing impact on management and conservation, offers a summary of current diagnostics, and suggests future direction for the development of diagnostic tests. The latter will be key in understanding and managing this disease.

Toxoplasmosis in Zoo Animals: A Retrospective Pathology Review of 126 Cases.

Toxoplasma gondii is an extremely successful zoonotic protozoan parasite that has been demonstrated in a wide range of endo- and poikilothermic species. Although infection is widespread amongst domestic animals, overt disease other than abortion in small ruminants is sporadic. This survey evaluates toxoplasmosis in zoo animals based on a systematic review of pathology archive material (n = 33,506 submissions) over a 16-year study period. A total of 126 submissions, deriving from 32 zoos, two educational facilities and two private owners, were included in the study, based on gross lesions, cytological, histological and immunohistological diagnosis of toxoplasmosis. Clinical history, signalment, annual distribution and post-mortem findings were evaluated. A total of 31 species (mammalian 97%/avian 3%) were represented in the study material. Ring-tailed lemurs, slender tailed meerkats, Pallas' cats, and squirrel monkeys were most affected. An unusual outbreak occurred in Asian small-clawed otters, in which toxoplasmosis has not been reported to date. Clinically, animals over 12 months of age presented with non-specific symptoms (anorexia, weight loss, lethargy, debilitation), neurological, gastrointestinal or respiratory signs and sudden death. Systemic disease predominated, with a propensity for encephalitis in meerkats and Pallas' cats and systemic disease involving lymphoid tissues in ring-tailed lemurs. Cases in the UK occurred year-round, with species-specific peaks and increases between August and November. This study reinforces the importance of toxoplasmosis as a significant cause of sporadic and epizootic mortalities in a wide range of zoo animals. Feral cat control is crucial to reduce infection pressure.

Imaging visuospatial memory in temporal lobe epilepsy-Results of an fMRI study.

PURPOSE: Impairment of cognitive functions is commonly observed in temporal lobe epilepsy (TLE). The aim of this study was to assess visuospatial memory functions and memory-related networks using an adapted version of Roland's Hometown Walking (RHWT) functional MRI (fMRI) task in patients with TLE. METHODS: We used fMRI to study activation patterns based on a visuospatial memory paradigm in 32 TLE patients (9 right; 23 left) and also within subgroups of lesional and non-lesional TLE. To test for performance, a correlational analysis of fMRI activation patterns and out-of-scanner neuropsychological visuospatial memory testing was performed. Additionally, we assessed memory-related networks using functional connectivity (FC). RESULTS: Greater contralateral than ipsilateral mesiotemporal (parahippocampal gyrus/hippocampus) activation was observed in left (n = 23)/right (n = 9) TLE. In lesional left TLE (n = 17), significant activations were seen in right more than left mesiotemporal areas (parahippocampal gyrus), while non-lesional left TLE patients (n = 6) showed significant bilateral (left>right) activations in mesiotemporal structures (parahippocampal gyrus). In left TLE, visuospatial cognitive testing correlated with fMRI activations in left (parahippocampal gyrus) and right mesiotemporal structures (hippocampus), characterized by greater fMRI activation being associated with better memory scores. In right TLE, higher scores in visuospatial memory testing were associated with greater fMRI activations in left and right insular regions. FC patterns of memory-related networks differ in right and left TLE. CONCLUSION: While TLE in general leads to asymmetrical mesiotemporal activation, lesion-induced and non-lesional TLE patients reveal different memory fMRI activation patterns. In right TLE, insular regions try to compensate for impaired right mesiotemporal structures during the performance of visuospatial tasks. Underlying functional visuospatial memory networks differ in right and left TLE.

Computer-assisted mitotic count using a deep learning-based algorithm improves interobserver reproducibility and accuracy.

The mitotic count (MC) is an important histological parameter for prognostication of malignant neoplasms. However, it has inter- and intraobserver discrepancies due to difficulties in selecting the region of interest (MC-ROI) and in identifying or classifying mitotic figures (MFs). Recent progress in the field of artificial intelligence has allowed the development of high-performance algorithms that may improve standardization of the MC. As algorithmic predictions are not flawless, computer-assisted review by pathologists may ensure reliability. In the present study, we compared partial (MC-ROI preselection) and full (additional visualization of MF candidates and display of algorithmic confidence values) computer-assisted MC analysis to the routine (unaided) MC analysis by 23 pathologists for whole-slide images of 50 canine cutaneous mast cell tumors (ccMCTs). Algorithmic predictions aimed to assist pathologists in detecting mitotic hotspot locations, reducing omission of MFs, and improving classification against imposters. The interobserver consistency for the MC significantly increased with computer assistance (interobserver correlation coefficient, ICC = 0.92) compared to the unaided approach (ICC = 0.70). Classification into prognostic stratifications had a higher accuracy with computer assistance. The algorithmically preselected hotspot MC-ROIs had a consistently higher MCs than the manually selected MC-ROIs. Compared to a ground truth (developed with immunohistochemistry for phosphohistone H3), pathologist performance in detecting individual MF was augmented when using computer assistance (F1-score of 0.68 increased to 0.79) with a reduction in false negatives by 38%. The results of this study demonstrate that computer assistance may lead to more reproducible and accurate MCs in ccMCTs.

Bridging the Species Gap: Morphological and Molecular Comparison of Feline and Human Intestinal Carcinomas.

Limited availability of in vivo experimental models for invasive colorectal cancer (CRC) including metastasis and high tumor budding activity is a major problem in colorectal cancer research. In order to compare feline and human intestinal carcinomas, tumors of 49 cats were histologically subtyped, graded and further characterized according to the human WHO classification. Subsequently, feline tumors were compared to a cohort of 1004 human CRC cases. Feline intestinal tumors closely resembled the human phenotype on a histomorphological level. In both species, adenocarcinoma not otherwise specified (ANOS) was the most common WHO subtype. In cats, the second most common subtype of the colon (36.4%), serrated adenocarcinoma (SAC), was overrepresented compared to human CRC (8.7%). Mucinous adenocarcinoma (MAC) was the second most common subtype of the small intestine (12.5%). Intriguingly, feline carcinomas, particularly small intestinal, were generally of high tumor budding (Bd) status (Bd3), which is designated an independent prognostic key factor in human CRC. We also investigated the relevance of feline CTNNB1 exon 2 alterations by Sanger sequencing. In four cases of feline colonic malignancies (3 ANOS, 1 SAC), somatic missense mutations of feline CTNNB1 (p.D32G, p.D32N, p.G34R, and p.S37F) were detected, indicating that mutational alterations of the WNT/ß-catenin signaling pathway potentially play an essential role in feline intestinal tumorigenesis comparable to humans and dogs. These results indicate that spontaneous intestinal tumors of cats constitute a useful but so far underutilized model for human CRC. Our study provides a solid foundation for advanced comparative oncology studies and emphasizes the need for further (molecular) characterization of feline intestinal carcinomas.

Histopathological Characterization of Colitis in Captive Western Lowland Gorillas (Gorilla gorilla ssp gorilla).

In captive gorillas, ulcerative colitis is an important cause of morbidity and mortality with no established definitive aetiopathogenesis. The aim of the study was to characterize histopathologically colonic lesions in captive western lowland gorillas (Gorilla gorilla ssp gorilla) and to apply the Nancy index, a disease activity scoring system for ulcerative colitis in humans. Colon samples from 21 animals were evaluated on the basis of histopathological characteristics for the diagnosis of inflammatory bowel disease in humans and divided into acute or chronic changes. The most common acute changes included the presence of neutrophils in the lamina propria (17/18; 94%), mucosal and submucosal oedema (12/18; 67%) and crypt abscesses (8/18; 44%). The most common chronic changes were lamina proprial lymphoplasmacytic infiltrates (17/18; 94%) and crypt dilation or distortion (6/18; 33%). Based on the Nancy index, 4/21 (19%) cases were grade 4 (the highest grade), 2/21 (10%) were grade 3, 11/21 (52%) were grade 2 and 4/21 (19%) cases were grade 0. The colonic changes were comparable to the acute phase of ulcerative colitis in humans. No unifying aetiopathogenesis could be identified. The Nancy index proved to be a valuable tool for the standardization of disease grading and established a basis for future studies of gorilla colitis.

Cryptococcus Infection in Captive Callitrichids in the United Kingdom.

Cryptococcosis is widely reported in North America and Australia but considered rare in the UK. Disease is mainly caused by Cryptococcus neoformans and Cryptococcus gattii and affects animals and humans. Cases of cryptococcosis have been described in non-human primates, including a few in the Callitrichidae family. Six captive callitrichids from five zoological facilities in the UK were diagnosed with cryptococcosis on post-mortem examination over a 13-year period. Histological examination revealed intralesional yeast bodies consistent with Cryptococcus spp in lung, brain, lymph nodes, larynx, salivary gland and ears. C. neoformans was confirmed in two cases by culture and by culture and polymerase chain reaction (28S rRNA gene), respectively. This case series is the first report of Cryptococcus spp in captive callitrichids in the UK and reinforces the need to include this fungal disease in the differential diagnosis of sick callitrichids in zoo settings.

A novel dicistrovirus in a captive red squirrel (Sciurus vulgaris).

Dicistroviruses are single-stranded RNA viruses in the family Dicistroviridae. The viruses have mainly been detected in arthropods and are the cause of several devastating diseases in many of these species such as honeybees. Increasingly, dicistroviruses have also been detected in both mammalian and avian species in faeces, blood and liver, but with unconfirmed pathology. Here, we report a novel dicistrovirus detected in the intestinal content of a captive red squirrel with enteritis along with the disease history, pathology and genomic characterisation of the virus. Virus particle morphology resembled those of picornaviruses with a diameter of 28-32 nm but failed to be detected using a mammalian/avian pan viral microarray. Next-generation sequencing confirmed a dicistrovirus having a typical dicistrovirus genome organization, but with the polyprotein 1 being shorter by about 100 amino acids, compared to that of other dicistroviruses. Phylogenetic analysis of ORF1 and ORF2 sequences clustered the virus with two yet unassigned dicistroviruses detected in Gorilla gorilla and a freshwater arthropod and likely to be designated to a new genus. Our data further highlights the ever-growing diversity of dicistroviruses, but the clinical significance of the virus in mammalian species and particularly red squirrels has yet to be established.

EARLY-ONSET LEUKOENCEPHALOMYELOPATHY AND POLYNEUROPATHY IN EASTERN QUOLLS (DASYURUS VIVERRINUS) IN THE EUROPEAN CAPTIVE POPULATION.

Leukoencephalomyelopathy (LEM) is suggested to be an age-related degenerative condition in geriatric Eastern quolls (Dasyurus viverrinus), manifesting in animals greater than 3.5 yr of age. This case series describes four LEM cases from two zoologic collections; three in nongeriatric animals, with one only 1 yr of age, and details advanced diagnostic investigation, including magnetic resonance imaging, cerebrospinal fluid analysis, and electrodiagnostic studies, not previously reported in Eastern quolls. Animals presented clinically with forelimb proprioceptive deficits and hindlimb and lumbar muscle hypotrophy, which were not noted in previous reports, in addition to hindlimb ataxia. Blindness and emaciation, which have been reported previously, were not seen. Disease progression was variable, and time from first clinical signs to euthanasia ranged from 46 days to over 2 yr. Histopathologic findings in the central nervous system were typical of those in previous LEM cases; concomitant polyneuropathy was observed in two quolls. Our findings suggest that age-related degeneration may not be the only cause of LEM in Eastern quolls. Because all quolls were related, a familial component cannot be excluded. LEM should be further investigated for its potential impact on future captive breeding programs, and our findings suggest that daily quality-of-life assessment should guide euthanasia of affected animals.

A RETROSPECTIVE STUDY OF MORBIDITY AND MORTALITY IDENTIFIED AT POSTMORTEM EXAMINATION OF CAPTIVE LANGURS (TRACHYPITHECUS SPP) FROM SIX UNITED KINGDOM ZOOLOGICAL INSTITUTIONS: A 19-YEAR REVIEW.

Langurs are Asian primates belonging to the Colobinae subfamily. Langur populations are declining, with most species categorized as threatened by the International Union for Conservation of Nature. Investigation into the threats to population viability and sustainability would be beneficial but there is limited literature available on common diseases or causes of death in these species, either in captive or free-ranging settings. This study aimed to evaluate the most common causes of morbidity and mortality in Trachypithecus species submitted for postmortem examination by six United Kingdom zoological institutions between 2001 and 2020, to inform best practice husbandry guidelines. Necropsy and histopathology reports from 88 individuals of Trachypithecus species from six zoological organizations in the United Kingdom were analyzed. Species included Javan langurs (Trachypithecus auratus; n = 35), dusky langurs (Trachypithecus obscurus; n = 28), François' langurs (Trachypithecus francoisi; n = 16), purple-faced langurs (Trachypithecus vetulus; n = 4), silvered langurs (Trachypithecus cristatus; n = 4), and Phayre's langur (Trachypithecus phayrei; n = 1). Morbidities and causes of death were recorded. Gastrointestinal diseases and systemic infections were the leading causes of death (27.4% and 21.0% of cases where cause of death was known, respectively); linear foreign bodies were the most common cause of death. Interstitial pneumonia was frequently observed secondary to systemic infection. Heart abnormalities, anthracosis, and hemosiderosis were common but not directly associated with mortality. Further investigation is necessary to assess the importance of these conditions and whether they predispose to other diseases. This study provides a baseline for future research evaluating captive and free-ranging langur health and highlights husbandry practices that may decrease morbidity in these species.