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.

RISK FACTORS ASSOCIATED WITH YOLK SAC RETENTION IN CAPTIVE-BRED HUMBOLDT PENGUIN (SPHENISCUS HUMBOLDTI) CHICKS.

Multiple occurrences of yolk sac retention prompted a retrospective investigation in a recently formed colony of captive Humboldt penguins (Spheniscus humboldti). Necropsy reports of 141 parent-reared penguin chicks that died between January 2014 and December 2018 were reviewed for evidence of yolk sac retention, defined as the presence of a yolk sac at postmortem examination of a chick aged 7 d or greater, and analyzed by demographic and pathological variables for identification of risk factors. Fifty-nine (65%) chicks that died at age 7 d or greater had a retained yolk sac at postmortem examination, revealing that this was a common condition in penguins in this population. Chicks that retained their yolk sac were also more likely to present with minimal gut contents (P = 0.02), have a prominent bursa of Fabricius (P < 0.01), and be the first chick hatched of their clutch (P = 0.02). Parental experience and age were not predictive of yolk sac retention, but there was a trend for chicks with retained yolk sacs to present with a poorer body condition, reduced weight, and reduced crown-rump length compared to chicks without a retained yolk sac. Histopathological and bacteriological findings of retained yolk sacs were not significantly different from those of chicks under 7 d of age. Although likely to be multifactorial, the association between yolk sac retention and indicators of suboptimal feed intake and growth (empty gastrointestinal tract, poor body condition score, decreased crown-rump length, and decreased weight at death) is hypothesized to be a result of parental neglect, leading to starvation and absorption arrest of the yolk, as previously indicated in broiler chicks.

The past, present and future of hormonal contraceptive use in managed captive female tiger populations with a focus on the current use of deslorelin acetate.

Tigers (Panthera tigris spp.) are endangered in the wild; ensuring sustainable insurance populations requires careful planning within zoological collections. In captive situations, contraceptives are often used to control breeding and ensure genetically viable populations that contain manageable numbers of animals; reversible contraceptives are ideal because they offer flexibility for breeding management. Historically, synthetic progestins, such as melengestrol acetate implants, were used in female tigers, but these are associated with an increased risk of reproductive pathology and subsequent infertility. Recent management advice to ex-situ collections has been to transition to the use of gonadotropin-releasing hormone agonists, such as deslorelin acetate implants, which do not appear to have a similar risk of reproductive pathology but are associated with highly variable reversal times in exotic felids. Using data from 917 contraceptive records in female tigers captured by the Association of Zoos and Aquariums Reproductive Management Center and the European Association of Zoos and Aquaria Reproductive Management Group's joint Contraception Database and from supplementary surveys, this study reviews the changing use of contraceptives in captive female tigers. The aim was to describe the historical and current use of contraceptives and provide a comprehensive assessment on the use of deslorelin implants, including data on product protocols, efficacy, pathology, and reversibility. This study determined that current dose, frequency, reversibility, and anatomical placement sites of deslorelin implants are highly variable, indicating that specific, readily available, unified, evidence-based recommendations on the use of deslorelin would be useful for future contraceptive use in managed tiger populations.

Diagnosis and Treatment of Heavy Metal Toxicosis in Six Waldrapp Ibis (Geronticus eremita).

Six adult Waldrapp ibis (Geronticus eremita) were presented with heavy metal toxicosis secondary to paint chip ingestion after being placed in an indoor confinement enclosure because of a regional highly pathogenic avian influenza epornitic and government restrictions. Four of the ibis developed clinical disease signs between 45 and 64 days of confinement, including weakness, lethargy, inability to fly, low body condition, and bilateral wing droop while 2 birds appeared to remain normal during that period. Common clinicopathological findings included elevated plasma aspartate aminotransferase, creatine kinase, glutamate dehydrogenase, and bile acids values. Erythrocyte morphological changes included prominent hypochromasia, decreased size of polychromatophils with occasional cytoplasmic stippling, abnormal shapes, and D cells. Whole-body radiographic imaging revealed particulate radio-opaque material in the ventriculus of all affected birds. One bird died before chelation therapy could be instituted and heavy metal testing of the liver revealed increased concentrations of lead and zinc. Lead toxicosis was diagnosed in the 5 remaining birds by plasma lead analysis. These 5 birds were hospitalized for an average of 40 days and treated with sodium calcium edetate and fluid therapy, which resulted in resolution of the toxicosis. Plasma biochemistry, complete blood counts, and blood lead values were performed repeatedly on all 5 birds and were used to guide therapy and monitor treatment response. This case series emphasizes the importance of early contingency planning and reviews the treatment of lead toxicosis in birds with a focus on long-term clinical monitoring and hematology.

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.

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.

COMPARISON OF ISOFLURANE AND SEVOFLURANE FOR SHORT-TERM ANESTHESIA IN MEERKATS (SURICATA SURICATTA)-ARE THERE BENEFITS THAT OUTWEIGH COSTS?

Meerkats ( Suricata suricatta ) are routinely anesthetized with isoflurane in zoo and field settings. Twenty healthy adult meerkats of mixed age and sex held in the Zoological Society of London's collection were anesthetized with 4% isoflurane by face mask for routine health examinations. The procedure was repeated 5 mo later in the same group of animals utilizing sevoflurane at 5% for induction, and again 3 mo later with sevoflurane at 6.5% for induction to approximate equipotency with isoflurane. The speed and quality of induction and recovery were compared between the two volatile anesthetic agents. There was no statistically significant difference in the speed of induction across any of the anesthetic regimes. There was a significant difference in recovery times between isoflurane and 6.5% sevoflurane (427 ± 218 and 253 ± 65 sec, respectively [mean ± SD]). Under the conditions of this study, sevoflurane at 6.5% induction dose resulted in better quality induction and recovery than sevoflurane at 5% induction or isoflurane. The mean heart and respiratory rates during anesthesia were higher using 5% sevoflurane for induction but there was no significant difference in either rate between isoflurane and sevoflurane used at a 6.5% induction dose. This study suggests that sevoflurane at a dose of 6.5% for induction and 4% for maintenance is a safe and effective anesthetic agent in healthy adult meerkats. Rapid return to normal behavior after anesthesia is important in all zoo species but particularly so in animals with a complex social and hierarchical structure such as meerkats. For this species, the advantage afforded by the speed of recovery with sevoflurane may offset the cost in certain circumstances.

Analysis of biochemical markers of bone metabolism in Asian elephants (Elephas maximus).

Two human enzyme immunoassays (EIA) and one radioimmunoassay (RIA) were validated and used to measure osteocalcin (OC), bone alkaline phosphatase (BAP), and the cross-linked telopeptide domain of type I collagen (ICTP), in serum from Asian elephants (Elephas maximus). Sera from four adult females sampled on 7 consecutive days were also analyzed to assess the existence and magnitude of intraindividual day-to-day variability of the serum concentration of these markers. Sample dilution curves were parallel with assay standard curves, which demonstrated that excellent cross reactivity existed between assay antibodies and elephants marker antigens. Statistically significant inverse correlations were found between age and concentrations of all three markers: BAP, r = -0.862 (P < 0.01); OC, r = -0.788 (P < 0.002); and ICTP, r = -0.848 (P < 0.01). Strong positive correlations were found between BAP and OC (r = 0.797, P < 0.01), OC and ICTP (r = 0.860, P < 0.01), and between BAP and ICTP (r = 0.958, P < 0.01). No statistically significant intraindividual variability was found over 7 days in the four adult females for any of the markers assessed (OC: P = 0.089; ICTP: P = 0.642; BAP: P = 0.146; n=4 in each case). The overall coefficient of variability observed in this group of animals was 10.3%, 7.4%, and 5.5% for OC, BAP, and ICTP, respectively. These results suggest a potential role for biochemical markers of bone turnover in monitoring skeletal health and bone disease in Asian elephants.