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.

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.

HEALTH SCREENING OF THE EUROPEAN ENDANGERED SPECIES PROGRAM CAPTIVE POPULATION OF THE PINK PIGEON (NESOENAS MAYERI).

The population of the Mauritian pink pigeon (Nesoenas mayeri) fell to fewer than 20 individuals in the 1970s. Following intensive conservation efforts, the free-living population is now estimated to be 470 individuals. However, because of the population bottleneck the species remains at risk of extinction because of genetic loss and inbreeding depression. A European captive population was established in 1977 and a European Endangered Species Program (EEP) was formalized in 1992. As birds in the EEP captive population possess unique alleles not observed in the surviving free-living birds, the EEP management plan recommends transferring EEP birds to Mauritius to improve genetic diversity. Health screening of the current EEP population to identify circulating pathogens was performed. Forty-two birds from three collections in the United Kingdom and one in Jersey were screened for a wide range of pathogens, present clinically or subclinically, including important viruses, bacteria, protozoa, and helminths. Eleven birds tested positive for at least one pathogen: Trichomonas spp. (5), Yersinia kristensenii (2), Yersinia aleksiciae (1), coccidial oocysts (3), and strongyle ova (3). None of the positive birds showed overt signs of clinical disease, although two birds with Trichomonas spp. had suboptimal body condition. Genotyping of one Trichomonas gallinae sample revealed a type-C strain (low pathogenicity). The results from this screening will contribute towards a disease risk assessment, to create a pre-export protocol for translocation of captive EEP birds to Mauritius.

A RETROSPECTIVE REVIEW OF POST-METAMORPHIC MOUNTAIN CHICKEN FROG (LEPTODACTYLUS FALLAX) NECROPSY FINDINGS FROM EUROPEAN ZOOLOGICAL COLLECTIONS, 1998 TO 2018.

The mountain chicken frog (Leptodactylus fallax) is the largest endemic amphibian species in the Western Hemisphere. Since 1998, this critically endangered species has been maintained as a European Endangered Species Programme, but low breeding success and a high mortality rate threaten the sustainability of the captive frog population. In the current study, we analyzed gross and histopathologic postmortem information from 212 mountain chicken frogs that died in European zoological collections from 1998 to 2018. Thin body condition was the most commonly reported finding across all submissions, observed in 125 frogs. The gastrointestinal and urinary systems were reported to have the highest prevalence of pathologic findings on gross and histopathologic examination. Inflammatory disease was the most frequent diagnosis after histopathologic examination of relevant tissues, with intestinal inflammatory disease (n = 76) followed by tubulointerstitial nephritis (n = 26) being the most commonly reported. Neoplasia was reported in 42 of 212 (19.8%) frogs, all of which were adults. A defined cause of death, or reason for euthanasia, was proposed for 164 of 212 (77.4%) frogs, with inflammatory diseases processes (74 of 212; 34.9%) most commonly implicated. Intestinal adenocarcinoma, seemingly restricted to the colon, caused the deaths of 31 adult frogs. Further investigations to determine factors contributing to the high incidence of inflammatory disease processes and neoplasia are advocated to improve the health and sustainability of the captive mountain chicken frog population.

RETROSPECTIVE REVIEW OF MORTALITY IN CAPTIVE PINK PIGEONS (NESOENAS MAYERI) HOUSED IN EUROPEAN COLLECTIONS: 1977-2018.

The Mauritian pink pigeon (Nesoenas mayeri) is vulnerable, with only 400 individuals remaining in the free-living population. A European captive population was established in 1977 and a European Endangered Species Program (EEP) in 1992. The EEP long-term management plan recommends integrating the EEP and free-living Mauritius populations through pigeon transfers. A retrospective mortality review of the captive population was performed as part of a disease risk assessment process and to inform infectious disease screening prior to exporting captive birds to Mauritius. Six hundred pink pigeons from 34 institutions died from 1977 to 2018. Each individual was categorized according to age at time of death. Records from 404 individuals were categorized according to cause of death. Neonatal mortality (39%) and juvenile mortality (10.8%) were most commonly caused by noninfectious diseases (52% and 54.4%, respectively), including parental neglect and failure to thrive in neonates and nutritional secondary hyperparathyroidism in juveniles. Trauma (43.1%) was the most common cause of mortality in adults, with significantly higher mortality in males from interspecific aggression and in females due to intraspecific aggression. Yersinia pseudotuberculosis, Mycobacterium avium, and Escherichia coli were the most common infectious causes of adult mortality, and E. coli was the most common infectious cause in neonates. The following infectious diseases were identified as priorities for pre-export disease risk analysis, though not all caused mortality: Y. pseudotuberculosis, M. avium, Trichomonas spp., Chlamydia psittaci, and Coccidia spp. Husbandry changes have been made over the years to mitigate many of the noninfectious causes of mortality. These include alterations to nest sites to reduce neonatal trauma and abandonment, ultraviolet light supplementation and diet optimization to reduce metabolic disorders, improving enclosure design to reduce impact trauma, allowing females rest periods during breeding season, and avoiding housing with certain species.

INHALATORY ISOFLURANE ANESTHESIA IN MOUNTAIN CHICKEN FROGS (LEPTODACTYLUS FALLAX).

One hundred and fourteen mountain chicken frogs were anesthetized, to place intracoelomic radiotracers. The animals were placed in a clear plastic bag that was filled with isoflurane 5% and oxygen. Loss of righting reflex occurred at 3.4 ± 2.3 min; loss of gular movements was observed at 7.6 ± 2.7 min. Intubation was carried out using a modified cuffed tube between 2.5 and 3.5 mm, at 7.6 ± 2.2 min from the beginning of the anesthesia. Manual intermittent positive pressure ventilation every 5 to 10 sec was initiated and maintained through the anesthesia. Isoflurane concentration was maintained at 2%. Loss of withdrawal reflex occurred at 10.6 ± 4.8 min, while loss of response to painful stimuli was noted at 11.1 ± 2.9 min. Surgery started at 16.9 ± 9.9 min; the procedure from incision to last suture took 8.2 ± 2.3 min. Total anesthesia time was 21 ± 6.4 min. Intermittent positive pressure ventilation was continued with room air until the animals recovered the righting reflex, which occurred at 40.4 ± 10.1 min.

DIVERSITY OF STAPHYLOCOCCAL SPECIES CULTURED FROM CAPTIVE LIVINGSTONE'S FRUIT BATS (PTEROPUS LIVINGSTONII) AND THEIR ENVIRONMENT.

Livingstone's fruit bats (Pteropus livingstonii) are critically endangered and a captive population has been established as part of the International Union for Conservation of Nature Species Action Plan. The largest colony, in Jersey Zoo, was sampled for staphylococcal carriage and at infection sites, as disease associated with staphylococci had previously been found. Staphylococci were cultured from swabs from 44 bats (skin, oropharynx, mouth ejecta, skin lesions) and from their enclosure. The isolates were identified by matrix-assisted laser desorption-ionization time of flight mass spectrometry; antimicrobial susceptibility testing was performed by disc diffusion and screening for mecA and mecC. Seventeen species of coagulase-negative staphylococci including Staphylococcus xylosus, S. kloosii, S. nepalensis, and S. simiae were isolated. Staphylococcus aureus was identified from both carriage and lesional sites. These findings suggest S. nepalensis may be part of the normal carriage flora of bats. Antimicrobial resistance rates were low and methicillin-resistant Staphylococcus aureus (MRSA) was not identified. Sampling of mouth ejecta for staphylococci may provide results representative for carriage sites.

Clinical and Pathological Aspects of Systemic Isospora Infection in Blue-crowned Laughing Thrushes (Garrulax courtoisi) at Jersey Zoo.

Based on a review of species mortalities, systemic Isospora species was identified as the primary cause of death in 22% (19 of 87) of blue-crowned laughing thrushes (BCLTs; Garrulax courtoisi) at the Jersey Zoo between 1997 and 2016. Fifty-eight percent of the affected birds were between 1 and 2 years old, and in 89% of cases, death occurred between August and December. Abnormal clinical findings in BCLTs with Isospora species infections included hepatomegaly and pectoral muscle myositis in 79% of the cases. The results of diagnostic blood testing in 90% of infected BCLTs 30 days before death were consistent with a severe leukocytosis with greater than 20% of mononuclear cells infected by merozoites. The most common lesions identified during gross necropsy examination were splenomegaly (100%), hepatomegaly (95%), and multifocal, raised, white foci in pectoral (84%) and heart (79%) muscle. Lymphohistiocytic inflammation was identified in the liver, heart, spleen, lung, striated muscle, and kidney tissue of birds with positive results for Isospora species. Merozoites were often observed in spleen, liver, pectoral muscle, and hearts of infected BCLTs. Polymerase chain reaction diagnostic testing that targeted the cytochrome c oxidase subunit, followed by Sanger sequencing, was used to confirm Isospora species in all 14 birds tested. Of samples tested, the highest genetic correlation was with GenBank accession number KT203397 (Isospora species JRB-2016 mitochondrion).

An exploratory investigation of echocardiographic parameters and the effects of posture on cardiac structure and function in the Livingstone's fruit bat (Pteropus livingstonii).

There is growing evidence that dilated cardiomyopathy may be a major cause of death in captive Livingstone's fruit bats (Pteropus livingstonii). Therefore, the primary aim of this prospective, exploratory study was to examine whether a systematic cardiac ultrasound protocol is feasible in this critically endangered species and to report basic measures of cardiac structure and function from a cohort of apparently healthy bats. A secondary aim was to test the effect posture (dorsal recumbency vs. roosting) has upon cardiac function in this species. Transthoracic echocardiograms, including 2D, Doppler, and tissue Doppler measures of cardiac structure and function were completed as part of routine health examinations for bats at a single center (n = 19). Bats were then grouped by age and disease status and the mean and range data reported for each group. In healthy adult bats, with the exception of a reduction in heart rate (P ≤ 0.05), right atrial systolic area (P ≤ 0.05), and right ventricular velocity during atrial contraction, there were no significant changes in cardiac structure or function in response to the roosting position. However, in the bats presenting with dilated cardiomyopathy the current data suggest that left ventricular ejection fraction is improved while roosting. Further work is required to confirm our initial findings, generate diagnostic reference intervals, and explore the causes of dilated cardiomyopathy in this species.

Development of a body condition score for the mountain chicken frog (Leptodactylus fallax).

The Critically Endangered mountain chicken frog (Leptodactylus fallax) has undergone drastic population decline due to habitat loss, hunting, invasive species, and chytridiomycosis. In response, several partner institutions initiated a conservation breeding program. It is important to maintain the captive population in good health. Therefore the program partners have recommended establishment of protocols for health examination of the species, including body condition assessment. Visual body condition scoring is a useful means to assess body condition in zoo animals for which regular bodyweight measurements are impractical or associated with capture-related stress. In this study, the authors developed a visual body condition score for the mountain chicken frog based on an ordinal categorical scale from 1 to 5 (1 = lowest body condition, 5 = highest body condition) using anatomical features that vary with total body energy reserves. Veterinary staff, animal managers, keepers, researchers, and students subsequently used the body condition score to assign scores to 98 mountain chicken frogs (41 male, 57 female) aged between 8 months and 12 years housed in five zoos in the UK and Jersey between February and March 2016. Body condition scores showed moderate (rho = 0.54; males) to strong (rho = 0.6; females) correlation with the scaled mass index, an objective measure of total energy reserves. The majority of pairwise comparisons between scores showed slight to substantial intra-observer agreement (93.8%) and slight to almost perfect inter-observer agreement (97.2%). Cases of poor agreement were likely due to limited observer experience working with the species.

Successful treatment of infertility in a female Sumatran orangutan Pongo abelii.

In 2011, a female Sumatran orangutan housed at Durrell Wildlife Conservation Trust became infertile following a massive antepartum hemorrhage in labor and the delivery of a stillborn infant. The placenta was infected with Pantoea sp. Hysterosalpingography (HSG) revealed blocked fallopian tubes, and pressurized fallopian tube perfusion was used to reverse the tubal occlusion. She subsequently conceived and following an intensive training program, we were able to measure umbilical artery waveform analysis for fetal well-being and placental localization to exclude placenta previa, which could complicate pregnancy and lead to catastrophic hemorrhage. The female went on to deliver a healthy offspring. We suggest that these techniques should be considered for other infertile females in the global captive population.

FEMORAL HEAD RESECTION IN TWO LIVINGSTONE'S FRUIT BATS (PTEROPUS LIVINGSTONII).

Two Livingstone's fruit bats (Pteropus livingstonii) presented with a unilateral partial paresis of the hind limbs. Radiographs revealed luxation of the coxofemoral joint and degenerative joint disease in the right coxofemoral joint in one case. The second case presented with recurrent luxation of the coxofemoral joint with osteoarthrosis of the femoral head. Clinical findings in both cases led to a decision to perform a femoral head resection. The performed surgery led to the recovery of normal function of the limb without any complications in both cases.

UTERINE RUPTURE AND CESAREAN SURGERY IN THREE RIO CAUCA CAECILIANS (TYPHLONECTES NATANS).

A uterine rupture of unknown etiology during gestation causing the death in a Rio Cauca caecilian ( Typhlonectes natans ) and successful anesthesia using tricaine methanesulfonate and cesarean section in three occasions in two other specimens because of suspected dystocia are described. One of the surgeries was performed at an early stage of embryo development, thereby preventing the survival of the neonates.

SEVOFLURANE ANESTHESIA IN LIVINGSTONE'S FRUIT BATS ( PTEROPUS LIVINGSTONII).

Fourteen captive Livingstone's fruit bats ( Pteropus livingstonii) were anesthetized for routine veterinary health checks, including echocardiography, using sevoflurane. In addition, three specimens suffering from cardiac disease and a pregnant specimen were anesthetized for clinical assessment. No anesthetic complications were observed in any of the specimens. Significant differences in the core body temperature were found between the esophageal and rectal measurements. A significant decrease in blood glucose was noted through the anesthesia, suspected to be related to an extended fasting period prior to the procedure.

MEDICAL MANAGEMENT OF DILATED CARDIOMYOPATHY IN LIVINGSTONE FRUIT BATS ( PTEROPUS LIVINGSTONII).

Eleven cases of dilated cardiomyopathy have been diagnosed and treated in captive Livingstone fruit bats ( Pteropus livingstonii) in the United Kingdom over the past 7 yr. All but one case received treatment with a diuretic plus an angiotensin-converting enzyme inhibitor (ACEI), and, or pimobendan. One case is still under treatment with pimobendan alone, following diagnosis before onset of clinical signs. Diuretic treatment consisted of furosemide at a dose rate of 0.5-5 mg/kg, one to three times daily, and, or spironolactone at a dose rate of 1-4 mg/kg, once or twice daily. When used, the ACEI imidapril was given at a dose rate of 0.24-0.38 mg/kg q 24 hr, and pimobendan at a dose rate of 0.2-0.5 mg/kg bid. This report is intended to provide anyone seeking to medically manage heart failure in Pteropus species, particularly P. livingstonii, with a review of drugs and doses that have been used.

RADIOGRAPHIC CARDIAC SILHOUETTE MEASUREMENT IN CAPTIVE LIVINGSTONE'S FRUIT BATS (PTEROPUS LIVINGSTONII).

Cardiomyopathies have been increasingly noted in the captive population of Livingstone's fruit bat ( Pteropus livingstonii ). The aim of this study was to produce a set of repeatable quantitative reference measurements that could be used to assess the cardiac size during radiographic examination of this species. Ventro-dorsal and lateral radiographs (n = 129) from a total of 42 individual Livingstone's fruit bats were examined. The control group radiographs (n = 102) consisted of 34 healthy individuals. Radiographic measurements were taken of structures within the thorax and then converted into ratios. These ratios from radiographs (n = 27) were also calculated for eight individuals with diagnosed cardiomyopathy. Vertebral Heart Scores (VHS) were calculated from right lateral radiographs and compared between the two groups. From all the data, only the width of the cardiac silhouette to the width of the thorax (the W : T ratio) in the ventro-dorsal view and the VHS were found to be significantly different between both groups (P < 0.05). The group with cardiomyopathies had a mean W : T ratio of 0.59 (±0.005) and a VHS of 9.77 (±0.89), while a mean W : T ratio of 0.54 (±0.004) and a VHS of 8.71 (±0.93) was established for healthy specimens.

HIGH PREVALENCE OF INTESTINAL ADENOCARCINOMA IN A CAPTIVE POPULATION OF AMAZON MILK FROG (TRACHYCEPHALUS RESINIFICTRIX).

: A series of eight cases of intestinal adenocarcinoma in Amazon milk frog (Trachycephalus resinifictrix) is described. All cases presented with signs of inappetence and weight loss, and evidence of large intestinal distention on gross postmortem, with six of the eight cases showing a grossly visible large intestinal mass. Histologic examination identified the mass as an intestinal adenocarcinoma in all cases. No specific etiologic agent could be identified. This is the first report of neoplasia in the Amazon milk frog, and the first reported series of amphibian gastrointestinal neoplasia.

DIAGNOSIS AND MANAGEMENT OF BENIGN PROSTATIC HYPERPLASIA IN A PIED TAMARIN (SAGUINUS BICOLOR).

An intact male pied tamarin (Saguinus bicolor) presented with a hunched posture while moving, dysuria, pollakiuria, and hematuria. After diagnostic imaging assessment and prostate biopsy, benign prostatic hyperplasia was diagnosed. Treatments with delmadinone acetate and osaterone caused clinical signs and hematuria to resolve temporarily for a variable period of time. Because of frequent recurrence, elective surgical castration was performed, leading to resolution of the clinical signs.

Evaluation of the phenol red thread tear test in falconiformes.

Falconiformes are active searchers and hunters that require visual precision to catch their prey and survive in the wild. Despite this, ocular disease is likely to be underdiagnosed in these species, at least in part because of limited proven diagnostic methods and lack of published scientific data. Tear film deficiency is recognized as an important ocular surface disease in dogs but has not been well evaluated in birds. To evaluate the phenol red thread (PRT) tear test as an alternative method to the Schirmer tear test (STT) for determining tear production in Falconiformes, we assessed the PRT tear test twice for each eye in 21 birds from the genus Falco. The mean PRT test values for the right (OD) and left (OS) eyes were OD=30.2±4.6 mm/15 s and OS=29.1±3.7 mm/15 s, with an overall PRT test value for both eyes (OU) of 30.6±4.2 mm/15 s. Good reproducibility was seen with the PRT test as shown by the strong positive correlation between the first and second tests in the birds. The PRT test method provides repeatable results that are easy to obtain, easy to read, and achieved under the same conditions as the STT.

Histopathological characterization and grading of chronic enterocolitis in Sulawesi crested macaques (Macaca nigra).

Sulawesi crested macaques (Macaca nigra) (SCMs) are critically endangered and frequently suffer from chronic intestinal disease in captivity. Often, despite routine diagnostic investigations and confirmation of intestinal inflammation, an aetiology cannot be identified, leading to a non-specific categorization as chronic enterocolitis rather than an aetiological diagnosis. This study evaluates the histological features of gastrointestinal tissues from 23 SCMs, comparing animals with a clinical history suggestive of chronic enterocolitis (n = 14) with those without gastrointestinal clinical signs (n = 9). Tissues were graded according to the Nancy index (NI), a scoring system used in human medicine to evaluate disease activity in ulcerative colitis, a common form of human inflammatory bowel disease (IBD). Additionally, inflammatory cells in the colonic lamina propria were visually identified by type, counted and subsequently compared between diseased and control animals. Moderate to severe lymphoplasmacytic inflammation and structural changes were most common in the colons of affected SCMs, whereas histopathological changes were absent or mild in all examined small intestine (n = 17) and stomach (n = 11) tissues. The colonic NI had a significant positive correlation with clinical disease severity and 57% (n = 8) of animals with clinical signs had a NI grade of ≥2, consistent with moderate to severe, active IBD. Half of SCMs with recurrent rectal prolapse (n = 6) had a NI grade of 0, suggesting that intestinal inflammation is not always part of this condition's pathogenesis. The numbers of colonic lymphocytes, plasma cells, neutrophils, macrophages and total leucocytes were significantly higher in diseased animals. This study validated the use of the NI in SCMs, enabling a more standardized histopathological evaluation of the colon in this species.