DIAGNOSTIC IMAGING AND OROTRACHEAL INTUBATION IN CLINICALLY HEALTHY WILD SUNDA PANGOLINS (MANIS JAVANICA) IN SINGAPORE.

Pangolins are amongst the most overexploited species in the world and all eight species of pangolins are threatened with extinction. These animals are rare in zoological collections and often suffer high mortality rates in captivity. Maintaining healthy populations in captivity has become more important with the declining populations in the wild, but knowledge of veterinary care of these animals is limited. Interpreting radiography and ultrasonography images in a patient can be challenging without knowledge of normal findings. The Wildlife Healthcare and Research Center (WHRC) at Mandai Wildlife Reserve (MWR) admits an average of 25 Sunda pangolins (Manis javanica) annually, which is a Critically Endangered species native to Singapore. All the pangolins are triaged on admission and anesthetized for a health assessment before release into the wild. Endotracheal intubation using an otoscope and stylet is a novel technique in the species that has been developed and is commonly performed with these pangolins. A retrospective study was done on 20 clinically healthy wild pangolins to determine normal ultrasonography and radiography findings in the species. Notable findings include the presence of radio-opaque particles in the stomachs of all pangolins, the presence of free fluid cranial to the left kidney (13/20), a spleen with multifocal hypoechoic regions (6/20), and open epiphyseal plates of long bones even in large individuals weighing as heavy as 6.8 kg. Ultrasonographic images and measurements of kidney, spleen, and adrenal gland sizes as well as intestinal, gallbladder, and urinary bladder wall thickness were also described. These diagnostic imaging findings can advance the veterinary care of captive and wild pangolins.

MANAGEMENT OF ENTAMOEBA INVADENS IN THE HERPETOLOGICAL COLLECTION AT THE SINGAPORE ZOO.

Amebiasis caused by Entamoeba invadens is an important disease in reptile collections, causing severe morbidity and mortality. Surveillance of the parasite at the Singapore Zoo was carried out over a 4-yr period by PCR testing on reptiles that presented with lethargy and enteritis for disease investigation. Asymptomatic reptiles sharing the same enclosures as positive individuals were also tested as part of outbreak investigation. Animals in the collection that tested positive for the parasite were treated with metronidazole at various doses, with the addition of paromomycin for two cases, until a negative PCR test result was obtained at the end of the treatment course. A total of 97 samples from 49 individuals across 19 species of reptiles were obtained, of which 24 samples (24.7%) from 19 animals were positive for E. invadens. Of these positive samples, 11 samples were for disease investigation, eight samples for outbreak surveillance, and five samples for treatment monitoring. Treatment was initiated for 10 animals, four of which were showing clinical signs of disease. The parasite was cleared in nine of these 10 animals (90%), with eight animals receiving metronidazole as a sole therapeutic agent. A total of nine animals died of the disease, four of which (44.4%) presented dead or died within 24 h of presentation. Necrotizing enteritis was a consistent postmortem finding resulting in gastrointestinal perforation in two cases, and coelomic adhesions and hepatic trophozoites were each seen in five animals. The results suggest that the management of Entamoeba epizootics in the collection requires prompt outbreak investigation. Diagnosis of the disease with advanced diagnostic tools like PCR, endoscopy, and ultrasonography and treatment with metronidazole in both symptomatic and asymptomatic animals may reduce mortalities during an outbreak.

MANAGEMENT OF A FATAL OUTBREAK OF STRONGYLOIDIASIS IN A CAPTIVE POPULATION OF PANTHER CHAMELEONS (FURCIFER PARDALIS) WITH IVERMECTIN.

An outbreak of the nematode Strongyloides sp. occurred in a population of 18 male and 29 female panther chameleons (Furcifer pardalis) at the Singapore Zoo. The parasite was first detected in one individual during routine microscopic examination of feces using the direct examination and magnesium sulfate flotation methods. The parasite was later found to have a closest match (98.96%) with Strongyloides sp. Okayama by DNA sequencing. Over a period of 6 mon, 97.9% (46/47) of the panther chameleons tested positive for the parasite, and 25.5% (12/47) of the animals died due to the disease. All the animals that died were female. Of the positive tests, magnesium sulfate flotation identified the parasite 98.1% (105/107) of the time, compared to direct fecal microscopy, which identified the parasite only 43.9% (47/107) of the time. Parasite eggs were detected in 100% (105/105) of the positive magnesium sulfate flotation tests but only 66.0% (31/47) of the positive direct fecal microscopy tests. Parasite larvae were detected in 61.7% (29/47) of the positive direct fecal microscopy tests but only 9.5% (10/105) of the magnesium sulfate flotation tests. Treatments with fenbendazole and pyrantel pamoate at published doses were ineffective at eliminating the parasite. Ivermectin (0.2 mg/kg PO q2wk for two doses) was successful at treating the parasite, with all animals testing negative for the parasite at the end of the treatment course without any observed adverse reactions. However, complete eradication of the parasite could not be achieved, as Strongyloides sp. could still be detected in the population on routine coproscopy intermittently over 3 yr. There were no further mortalities due to the disease with prompt treatment with ivermectin. Strongyloidiasis may cause high morbidity in panther chameleons, but severe disease leading to mortality can be prevented with the use of ivermectin.

Enterococcus casseliflavus infection in a captive Southern Cassowary (Casuarius casuarius): clinical and post-mortem findings.

An adult 22-year-old, male southern cassowary (Casuarius casuarius) presented for lethargy, dysorexia and soft feces. Clinical findings under chemical immobilization were unremarkable except for heterophilic toxic changes on blood smear, reduced albumin/globulin ratio and potentially elevated liver parameters. The animal was treated for suspected hepatobiliary insufficiency and received supportive treatment with daily subcutaneous fluids and medication and was monitored with a quality-of-life assessment. It was eventually euthanized after further deterioration. Post-mortem examination revealed vegetative valvular endocarditis, bile duct obstruction, cholangiohepatitis and splenitis with intralesional Enterococcus casseliflavus isolated. This is a first documented case of E. casseliflavus infection in a bird with multiorgan involvement.

Systemic and Cardiac Amyloidosis in Captive Celebes Crested Macaques (Macacanigra).

Systemic amyloidosis has been described in many animals and the most common form is reactive systemic AA amyloidosis. However, cardiac amyloidosis leading to heart failure is rare in animals. We now describe systemic and cardiac amyloidosis in two captive endangered Celebes crested macaques (Macaca nigra) at the Singapore Zoo. Both animals were geriatric and had chronic morbidities. Physical examination, radiography and ultrasonography revealed cardiac arrhythmia, pleural effusion, pulmonary oedema and ascites, consistent with cardiac failure. Amyloidosis was suspected and confirmed as type AA by immunohistochemistry.

Fatal Chryseobacterium indologenes infection in a captive red-shanked Douc langur (Pygathrix nemaeus).

We report a case of fatal Chryseobacterium indologenes infection in a captive juvenile red-shanked Douc langur in Singapore Zoo. The animal was treated for suspected melioidosis but died within 48 h. Chryseobacterium indolegenes was isolated from the liver and should be included as a differential for bacterial infections in the tropics.

Management of Entamoeba histolytica in the non-human primates at the Singapore Zoo.

Amebic dysentery caused by Entamoeba histolytica accounts for significant morbidity in the non-human primates (NHP) at the Singapore Zoo. This includes the animals in the collection as well as a sizeable free-roaming wild crab-eating macaque (Macaca fascicularis) population. The disease is of great concern because of its zoonotic potential. Passive surveillance, both ante and post-mortem, of NHP displaying clinical symptoms and active surveillance of NHP assessed to be at a higher risk of infection were carried out via fecal real-time polymerase chain reaction (PCR) testing for 4 years. Treatment of the disease with 25 mg/kg metronidazole BID for 10 days followed by 15 mg/kg paromomycin BID for 7 days achieved good clinical resolution in most cases that tested positive. Three diseased NHP with severe clinical signs of weight loss, lethargy, and diarrhea were anesthetized for veterinary diagnostic investigation. Mesenteric lymphadenopathy was consistently seen on ultrasound examination in these severe cases of entamoebiasis. Two animals eventually died of severe chronic enteritis due to the disease. The eradication of entamoebiasis in the NHP at the Singapore Zoo may be complicated by the maintenance of a disease reservoir in wildlife, but a combination of timely treatment and efforts at maintaining biosecurity can help manage the disease in the collection.

Treatments and outcomes of severe hemorrhagic enteritis in three eastern bongos (Tragelpahus eurycerus isaacii) at the Singapore Zoo.

Three eastern bongos (Tragelaphus eurycerus isaaci) presented acutely with hemorrhagic diarrhea at the Singapore Zoo, thought to be caused by a mouldy batch of hay. Repeated fecal tests were negative of parasites and common gastrointestinal bacteria including salmonella and campylobacter. The diarrhea resolved for all individuals after a week of leaf-only diet. However, 2 individuals developed signs of colic. Both animals were anesthetized for examination including blood tests and imaging studies. The findings were consistent of gastrointestinal ileus and a possible impaction. With intensive treatment involving repeated sedations for fluid therapy administration and treatments for gastrointestinal impaction, one individual eventually made a full recovery, but the other individual died due to septic peritonitis secondary to a rupture in the spiral colon. Persistent supportive therapy may be vital in treating severe gastrointestinal disease in this species.

Pyelonephritis and Cystic Endometrial Hyperplasia in a Captive Sunda Pangolin (Manis javanica).

The Sunda pangolin (Manis javanica) is one of the most trafficked animal species globally, and is listed as Critically Endangered by the IUCN. There is limited information on reproductive biology or pathology of this species. We now document the clinical and pathological features of pyelonephritis and cystic endometrial hyperplasia in one of these animals. Ultrasonographic examination revealed pathological changes in the kidneys and uterus. On histopathological examination, there was marked interstitial infiltration of macrophages, neutrophils and lymphocytes in kidney tissue, fibrinonecrotic ureteritis and mild endometrial hyperplasia. This first report of these urogenital lesions in this species will be valuable for the conduct of health and reproductive assessments of the Sunda pangolin, which inform conservation and ex-situ management of this species.