From July/2011 to June/2012, 31 green anaconda (Eunectes murinus) juveniles, progeny of a female anaconda purchased from Japan and added to the Ocean Park, Hong Kong collection in May/2011, died over a 12-month period. A novel paramyxovirus, named anaconda paramyxovirus (AnaPV), which belonged to the genus Ferlavirus, was isolated. In July/2015, one of the remaining two green anacondas died at the age of four, probably a result of prolonged incubation or latency of the AnaPV infection. In May/2024, a thorough examination on the ∼25-year-old green anaconda mother revealed multiple abnormalities, including grave anemia and intra-abdominal masses. The animal died shortly afterwards. The most important necropsy findings included an enlarged and unevenly firm pancreas with black pinpoint discolorations and thickened pancreatic duct, with histopathology findings suggestive of exocrine adenocarcinoma infiltrating into the duct and adjacent tissues and metastatic to the spleen; and severe membranous chronic and diffuse glomerulonephritis and severe acute renal tubular degeneration and necrosis. RT-PCR of the 179-bp partial L gene of AnaPV for the lung sample collected from the deceased anaconda mother was positive. Sequencing results showed that the sequence of the positive band was identical to that of AnaPV we previously published. The present study showed that AnaPV was capable of reactivation and causing infection in green anaconda after more than 10 years of latency. Further molecular surveillance studies in snakes of different species, genera and families, particularly in outbreaks due to unknown causes, would be important to discover additional members of the genus Ferlavirus.

Anencephaly is a deadly type of cephalic axial skeletal and neural disorder with a multifactorial aetiology that causes the failure of the rostral neuropore closure, compromising the formation of the neural folds, basicranium, and neurocranium. In cetaceans, there is only one report of this fetal abnormality, dated in late 1991, in a male stillborn Indo-Pacific bottlenose dolphin (Tursiops aduncus) and diagnosed using transabdominal ultrasonography on its mother that was kept under human care in the Ocean Park Corporation. After birth, physical and general radiographic examination showed kyphosis of the cervical and lordosis of the thoracic vertebrae, narrowed triangular skull base, thickening of an undersized maxilla, cranial vault defect including the absence of the bones constituting the roof of the cranial cavity. The stillborn was then fixed in formalin for future research. The preserved dolphin specimen was further investigated using different advanced radiological and imaging techniques postmortem, including 3D surface scanning (3DSS), computed tomography (CT), and magnetic resonance imaging (MRI). The scans were then used to conduct virtual necropsy (virtopsy) for detailed gross morphological analyses of the malformation. CT confirmed the total absence of the interparietal bone but also revealed the presence of greatly reduced other bones. The reduction of the parietal and occipital bone resulted in a large cranial vault defect instead of the interfrontal and fronto-occipital sutures. MRI showed the remaining of the optic and vestibulocochlear nerve which suggests the condition of human meroanencephaly. In summary, this study reported the importance of the use of advanced radiological and imaging tools in rare and complex malformations such as anencephaly in a stillborn cetacean. Although the malformation was diagnosed using prenatal transabdominal ultrasonography, it was later confirmed revealing new insights using virtopsy. Although ultrasound is an established method to monitor pregnancy, fetal growth and wellbeing, virtopsy provided a more accurate characterization of the bone and neural malformations postmortem. This example highlighted the importance of using virtopsy as a postmortem technique to understand the nature and characteristics of pathologies in cetaceans.

Reproduction of endangered wildlife, including elasmobranchs, is a fundamental mission of modern aquariums. Captive breeding programs necessitate artificial insemination to better utilize the limited stock in each facility. A cownose ray (Rhinoptera javanica) was successfully inseminated producing a live offspring. The semen was collected under chemical restraint, extended with a custom-made solution and kept chilled at 6°C for 24 hr. The quality of the semen was assessed at collection and just prior to insemination, noting color, volume, subjective sperm motility, sperm viability and concentration. Intrauterine insemination was carried out under chemical restraint. The monitoring of pregnancy was performed by serial ultrasound scans of the fetus assessing gilling and heartbeat. A healthy female pup was born after a gestation of 429 days (61 weeks and 2 days). Genetic microsatellite analysis confirmed that the pup was not a product of parthenogenesis and identified the donor male as the sire. This is the first report of a successful artificial insemination in an aplacental viviparous ray, suggesting these techniques can be applied to other species in this clade.

Rapid urbanization exacerbates human-wildlife conflict, particularly affecting synanthropic species, such as rhesus macaques (Macaca mulatta) in Hong Kong, who frequently venture into urban areas. To mitigate negative human-macaque interactions, the Agriculture, Fisheries and Conservation Department of the Hong Kong Government implemented a multipronged approach, which includes a long-term contraceptive program, regular population surveys, and a ban on intentional feeding. In this study, we described the contraceptive program implemented since 2009, conducted systematic population surveys to examine population trends and analyzed data to evaluate the effectiveness of the program since its commencement. We also conducted population viability analysis (PVA) to predict population trends under different sterilization intensities to inform future contraceptive efforts. We sterilized 1,923 individuals endoscopically. We found that the macaque birth rate dropped from 59

IntroductionCrocodilians have significant ecological, conservational, and economic roles. They are also commonly raised for commercial purposes and kept as zoological specimens. Although ultrasonography has been used in zoological contexts for health assessments of crocodilians, published studies on a detailed ultrasonography protocol and ultrasonographic anatomy are lacking. This study aimed to establish a standardized ultrasonography protocol and pictorial reference of the ultrasonographic appearances of the coelomic organs of crocodilians.MethodsA total of 7 crocodilians comprising 4 different species were included in this study. The crocodilians were manually restrained and underwent a non-contrasted and contrasted computed tomography (CT) scan, followed by an ultrasonography (USG) examination. Ultrasound fusion imaging technique enabled greater confidence in establishing a clear organ localization and correlation between modalities by visualizing the same anatomy from the same view angle.ResultsThe heart, caudal vena cava, liver, fat body (steatotheca), spleen, stomach, duodenal loops, pancreas, kidneys, testes, ovaries and cloaca were visualized in all species. Longitudinal and transverse images of the coelomic structures were acquired when possible. The ultrasonographic characteristics of the coelomic organs, including transducer positioning, acoustic window and approach, shape, size, marginations, and echo pattern were documented.DiscussionThe findings of this study provided a useful ultrasonographic protocol and anatomical reference of the coelomic organs in crocodilians. Invaluable insights into the practicality and adequacy of ultrasonography in evaluating the coelomic structures of crocodilians as part of health assessment and disease diagnosis were also discussed.

The overarching goal of a preventative medicine program is to minimize the chances of health problems developing and to maximize the chances of detecting health problems early, in a manner that best benefits the animals and the organization. The traditional paradigms of animal welfare, stemming from the five freedoms and being progressively fleshed out to five domains, the 24/7 approach and so forth do not apply perfectly to zoological collections and less so to animals undergoing veterinary treatments. The physiology and behaviour of animals undergoing veterinary treatments, including therapeutic, quarantine and preventative medicine, are derailed from their normal states and their choices and comfort are de facto limited. A paradigm separating animal wellbeing from animal welfare is necessary to instil clarity of thought and to guide actions in regard to the welfare of animals under human care. Using such a model, preventative medicine programs emerge as a cornerstone of zoo and aquarium animal welfare, all the more if it incorporates modern veterinary and husbandry techniques, including operant conditioning.

The objectives of this study were to assess the serological response to rabies vaccination in Hong Kong macaques and provide evidence-based recommendations for the vaccination interval implemented by the Government of Hong Kong. An inactivated rabies vaccine was administered subcutaneously to captured macaques under a mass sterilization program in Hong Kong. Blood samples from the animals were collected in a 2015 field survey and stored in −80°C freezer. In 2021, the frozen sera from vaccinated animals were prepared and tested for antibodies against the rabies virus using a commercial blocking enzyme-linked immunosorbent assay (ELISA) test. Sixty-five samples were available from the vaccinated macaques that had received at least one dose of the vaccine between 2008 and 2015. The interval between the first vaccination and blood sampling ranged from 21 to 2,779 days (median: 990). Only five macaques had a second vaccination record at the sampling time, all with high antibody levels. Among the remaining macaques, 77% (46/60) were positive for rabies antibodies. No specific association was observed between the post-vaccination period and the antibody titer of these macaques, and no adverse reactions were reported. Although the precise level of protection against a potential challenge with the rabies virus cannot be ascertained, the vaccination elicited rabies antibodies in 87% (21/24) of the macaques tested within 2.5 years of their first vaccination. Our findings indicate the potential benefits of the current vaccination strategy to protect the population from rabies and consequential mandatory culling of all macaques if a natural infection occurs.

A geriatric female giant panda developed grave signs of illness and was diagnosed with suspected hepatobiliary tract obstruction or other severe hepatic disease such as advanced cholangiohepatitis. The giant panda was euthanized and post mortem computed tomography was performed prior to necropsy. Common bile duct obstruction at the major duodenal papilla by a mineral attenuating calculus causing dilatation of common bile and gallbladder with concurrent multiple areas of liver abscess were detected by postmortem computed tomography. These were confirmed with gross necropsy. This is the first case report of common bile duct obstruction by mineral calculus with concurrent severe cholangiohepatitis in a giant panda.

Background Vessel collision induces blunt and sharp force traumas to aquatic animals and is a leading anthropogenic impact affecting cetaceans worldwide. Vessel collision is an important threat affecting vulnerable coastal cetaceans such as the Indo-Pacific humpback dolphins ( Sousa chinensis ) which reside in coastal waters of Hong Kong amongst heavy marine traffic. Case presentation A severely injured subadult S. chinensis was sighted in the waters off southwestern Hong Kong with four gaping incision wounds on its dorsum. It was in poor body condition and seemed unable to use the fluke effectively. The deepest wound located at the caudal peduncle near the base of the fluke and exposed the underlying fractured caudal vertebrae. The dolphin was monitored in the field over three weeks and eventually captured for medical intervention as veterinary assessment indicated progressive and life-threatening deterioration. During rehabilitation, the dolphin demonstrated initial signs of improvement over the first 36 hours as supported by diagnostic tests but then deteriorated rapidly. It was humanely euthanised after three days of rehabilitation. Postmortem investigation was carried out using virtopsy (postmortem computed tomography and magnetic resonance imaging) and conventional necropsy, with special attention to the traumatic musculoskeletal injuries caused by vessel collision and also revealed acute gastrointestinal compromise and respiratory disease that further hampered the rehabilitation. Conclusion In cetaceans, the prognosis for recovery from injuries caused by vessel collision depends on the extent, location, and gravity of the injuries (i.e., superficial, deep, penetrating, blunt vs. sharp, fresh vs. septic), as well as the health status of the individual and its ability to respond to the insult. Injuries extending deep into the vertebral column may lead to delayed death and associated welfare issues. The prognosis of this case was likely poor given the severity and location of the injuries, but the attempted rehabilitation and postmortem investigation provided valuable insights for clinical management if similar cases are encountered in the future. Being able to non-invasively assess and document traumatic injuries and other pathologies, diagnostic imaging is particularly useful in the clinical assessment and postmortem investigation (virtopsy) of cases with vessel-induced injuries.

Background: The Sunda pangolin, Manis javanica Desmarest, 1822, is a critically endangered species of pangolin that occurs from Indonesia to southern China. Knowledge of the biology and ecology of M. javanica is limited, however there have been previous reports of parasites, including nematodes, protozoans, ticks, and a cestode. Methods: An illegal shipment of 88 M. javanica carcasses, originally collected from wild populations throughout southeast Asia, were intercepted by Hong Kong border authorities (AFCD) and confiscated in 2018. Results: During necropsy, two different types of parasites were collected from four infected pangolins. The parasites were identified as the nematode Gendrespirura cf. zschokkei (Meyer, 1896) Chabaud 1958, which were embedded in the stomach wall, and the acanthocephalan, Oligacanthorhynchidae sp., collected from the intestine. Morphological descriptions and molecular characterization for each parasite type is provided. Conclusions: In addition, an updated list of parasites from pangolins, incorporating current taxonomic identifications and publications is presented.

In 2015, nearly 4000 critically endangered Palawan forest turtles (Siebenrockiella leytensis) were confiscated on their native island of Palawan in the Philippines after being illegally harvested for the international wildlife trade. Local conservation biologists and an international team of veterinary and husbandry personnel evaluated, treated, and repatriated the majority of turtles (88%) over a 3-mo period. Common pathologic findings included ophthalmic, dermatologic, musculoskeletal, and gastrointestinal lesions, including keratitis, osteomyelitis of the shell and digits, pododermatitis, and colonic nematodiasis. Hemogram results indicated severe leukocytosis in many individuals. Specimens for genetic analysis and molecular diagnostics were archived, and several intact carcasses were established as museum specimens. International collaboration may be required to ensure the confiscation and survival of illegally traded endangered wildlife, with ongoing efforts toward enhancing the law enforcement, husbandry, and veterinary capacity of range country personnel.

Rabies is a fatal zoonotic disease that can affect all mammals. Following the directives of the rabies ordinance of the Government of Hong Kong, all wild macaques captured under an ongoing sterilization program (since 2000) were vaccinated against rabies. The main objective of this study was to assess the serological response to rabies vaccination in the population of Hong Kong macaques. An inactivated rabies vaccine was subcutaneously administered to captured macaques under anesthesia. In a 2015 field survey, blood samples from the animals were collected and stored in -80℃ freezer. In July 2021, all frozen sera from vaccinated animals were prepared and tested for antibodies against rabies virus using a commercial enzyme-linked immunosorbent assay (ELISA) test. The test results were dichotomized at the recommended cut-off point of the test kit. Sixty-five samples from the vaccinated macaques were available for this study. All of these animals had received at least one dose of vaccine (1 vaccination) between 2008 and 2015. The interval between the 1 vaccination and blood sampling dates ranged from 21 to 2,779 days. Only five of the 65 macaques had a second vaccination record at the time of sampling; all five had high antibody levels. Among the remaining macaques, 77% (46/60) were positive for rabies antibodies. No specific association was observed between the post-vaccination period and the antibody titer of these macaques and no adverse reactions to vaccination were reported. The current vaccination strategy in Hong Kong macaques appears to effectively elicit rabies antibodies in a high proportion of macaque populations in the wild (78-87%). However, reaching the precise level of protection against a potential challenge with the virus should further be investigated.

In addition to human cases, cases of COVID-19 in captive animals and pets are increasingly reported. This raises the concern for two-way COVID-19 transmission between humans and animals. Here, we developed a SARS-CoV-2 nucleocapsid protein-based competitive enzyme-linked immunosorbent assay (cELISA) for serodiagnosis of COVID-19 which can theoretically be used in virtually all kinds of animals. We used 187 serum samples from patients with/without COVID-19, laboratory animals immunized with inactive SARS-CoV-2 virions, COVID-19-negative animals, and animals seropositive to other betacoronaviruses. A cut-off percent inhibition value of 22.345% was determined and the analytical sensitivity and specificity were found to be 1:64–1:256 and 93.9%, respectively. Evaluation on its diagnostic performance using 155 serum samples from COVID-19-negative animals and COVID-19 human patients showed a diagnostic sensitivity and specificity of 80.8% and 100%, respectively. The cELISA can be incorporated into routine blood testing of farmed/captive animals for COVID-19 surveillance.

A 13-year-old Bornean orangutan diagnosed with life threatening Streptococcus pyogenes broncho-pneumonia was kept in a state of deep sedation for 20 days via continuous intra-venous (IV) infusion of zolazepam -tiletamine and IV haloperidol to allow consistent IV administration of ceftazidime and gatifloxacine. The use of long-term deep sedation allowed carrying out a particularly demanding treatment not generally associated with zoological patients. The treatment was ultimately successful.

We disclose a peculiar rotational propulsion mechanism of Ray sperms enabled by its unusual heterogeneous dual helixes with a rigid spiral head and a soft tail, named Heterogeneous Dual Helixes (HDH) model for short. Different from the conventional beating propulsion of sperm, the propulsion of Ray sperms is from both the rotational motion of the soft helical tail and the rigid spiral head. Such heterogeneous dual helical propulsion style provides the Ray sperm with high adaptability in viscous solutions along with advantages in linearity, straightness, and bidirectional motion. This HDH model is further corroborated by a miniature swimming robot actuated via a rigid spiral head and a soft tail, which demonstrates similar superiorities over conventional ones in terms of adaptability and efficiency under the same power input. Such findings expand our knowledge on microorganisms' motion, motivate further studies on natural fertilization, and inspire engineering designs.

Slow lorises are enigmatic animal that represent the only venomous primate lineage. Their defensive secretions have received little attention. In this study we determined the full length sequence of the protein secreted by their unique brachial glands. The full length sequences displayed homology to the main allergenic protein present in cat dander. We thus compared the molecular features of the slow loris brachial gland protein and the cat dander allergen protein, showing remarkable similarities between them. Thus we postulate that allergenic proteins play a role in the slow loris defensive arsenal. These results shed light on these neglected, novel animals.

Here we report on the infection of captive crested geckos Correlophus ciliatus Guichenot (Reptilia: Diplodactylidae), with adults of the ascaridoid nematode, Hexametra angusticaecoides Chabaud & Brygoo, 1960 (Ascarididae). A population of captive crested geckoes became ill and died within a short period of time. Nematodes were recovered from the crested geckoes examined from within the coelomic cavity, penetrating various organs and migrating through subcutaneous tissues, as well as emerging through the geckos' skin. One gecko was treated with levamisole following surgical excision of nematodes from under the skin; this gecko survived. The potential source of the nematode infection in the captive geckoes is discussed. It is most likely that wild-caught Madagascan mossy geckoes, Uroplatus sikorae Boettger (Reptilia: Gekkonidae), introduced the infection to the colony. Molecular sequences of the nematodes are the first produced for the members of this genus. A redescription of the species and its genetic characterization based on the internal transcribed spacer sequence data is provided, suggesting some of the morphological criteria that have been used in the past to distinguish between Hexametra spp. may have been intraspecific morphological variations.

Basic ecological understanding is important for effective management of introduced species. If the species is rare or threatened in its native ranges, ecological knowledge gained from its introduced ranges may offer useful information for conservation. We radio-tracked 12 adult Physignathus cocincinus in Hong Kong, where it is introduced, to investigate their home range, movements, and habitat use. The home range of all P. cocincinus covered the stream, but 66% of relocations occur >5 m away from the stream. Movements did not differ between sexes and seasons. Females stayed at a longer distance from the stream than males. Lizards preferred woodland and concrete structures over orchards. For microhabitats, they preferred wider streams, greater height, and denser canopy cover. This infers the high association of this species with streams and riparian forests, which may be crucial for the establishment of introduced populations. To effectively manage the introduced populations through eradication efforts, areas away from streams (5-100 m) needs to be covered.

Reproductive hormones in serum concentrations of progesterone, estradiol, and testosterone in female Indo-Pacific bottlenose dolphins (Tursiops aduncus, n = 12) housed in Ocean Park Hong Kong were investigated in the present study. Results showed that, onset of puberty of captive Indo-Pacific bottlenose dolphins was at 5 years while sexual maturity was at 6. Average serum progesterone concentrations in non-pregnant sexually mature individuals was 0.33 (0.25-0.97) ng/mL (interquartile), significantly higher than in immature ones 0.26 (0.25-0.38) ng/mL. This study found significant difference in serum estradiol concentrations between individuals at the onset of puberty (9.5 ± 1.7 pg/mL, ±SD) and not (below detection limit 9 pg/mL). A slightly seasonal breeding pattern, with progesterone values tend to be higher from February to October (0.38 [0.25-1.07] ng/mL) was inferred. During pregnancy, serum progesterone concentrations range from 10.54 ± 8.74 ng/mL (indexed month post-conception [IMPC] 0) to 25.49 ± 12.06 ng/mL (IMPC 2), and display a bimodal pattern with 2 peaks in early- (25.49 ± 12.06 ng/mL, IMPC 2) and late-pregnancy (21.71 ± 10.25 ng/mL, IMPC 12), respectively. Serum estradiol concentrations can seldom be detected in early-pregnancy and increase constantly in mid- (9.45 ± 1.83 pg/mL) and late-pregnancy (11.88 ± 3.81 pg/mL), with a spike (15.45 ± 6.78 pg/mL) 1 month prior to delivery. Serum testosterone concentrations elevate significantly in IMPC 7 (0.36 ± 0.10 ng/mL) compared to other months (0.16 ± 0.10 ng/mL) of the year. The present study provides normal concentration profiles for some reproductive hormones in female Indo-Pacific bottlenose dolphins and can contribute to the breeding monitoring of this species. Also, our study would shed further light on the reproductive physiology of small cetaceans.