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.

Mitochondrial Gene Diversity and Host Specificity of Isospora in Passerine Birds.

Isospora infections are common in both wild and captive passerine species. Many bird species have been shown to have co-evolved with a particular species of Isospora. Disease can range from subclinical to severe and fatal, making infection and transmission of this parasite a concern for birds under managed care, particularly in institutions housing endangered species for breeding and reintroduction purposes. Whether birds in mixed-species enclosures represent a risk factor for severe isosporiasis due to infection with non-host-adapted strains is of concern for institutions managing these populations. To begin answering this question, we sought to characterize the host-specificity of Isospora spp. in a large number of passerine birds via retrospective sequencing of mitochondrial gene cytochrome c oxidase subunit I (COI). Despite outliers, Isospora sequences largely grouped by host species and/or host family. Additional research is warranted into the degree of interspecies transmission and host-switching of Isospora parasites, and risk factors for the development of severe disease in passerine birds.

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.

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.

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).

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.

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.

Radiographic evaluation of cardiac size in four Falconiform species.

To establish reference values for the cardiac size during radiographic examination in 4 species of Falconiformes used for falconry, lateral and ventrodorsal radiographs were examined from healthy birds of 4 species: Harris' hawks (Parabuteo unicinctus) (n = 48), peregrine falcons (Falco peregrinus) (n = 35), saker falcons (Falco cherrug) (n = 19), and lanner falcons (Falco biarmicus) (n = 13). On the lateral view, ratios between the length of the heart from base to apex and total length of the carina were calculated. On the ventrodorsal view, ratios between the width of the heart at its widest point and the distance between the ribs at the same level and between the width of the coracoid immediately caudal to the humeral articular surface in the shoulder joint and width of the heart and the distance between the ribs were calculated. No differences were found between species in the ratio of length of the heart/length of the carina. The ratios of width of the heart/distance between ribs and width of the heart/coracoid width differed between hawks and falcons but did not differ between the 3 falcon species.