Comparison of Estimated Wild Giant Anteater (Myrmecopahaga tridactyla Linnaeus, 1758) Diets with Commercial Diets for Insectivores: Implications for Anteater Health.

Using the stomach contents of 24 wild road-killed giant anteaters as proxies for their diet, we found that estimated wild diets were much lower in calcium (about ten times less) and phosphorus compared with manufactured feeds commonly fed to anteaters under human care. Indicators of soil consumption, such as ash, iron, and manganese were higher in the stomach contents than in either wild termites or manufactured diets, likely due to high levels of soil ingestion during feeding in the wild. Protein and fat levels in insects, stomach contents, and commercial diets all met carnivore recommendations. Both giant anteaters and tamanduas in managed care often develop hypercalcemia, perhaps because these taxa have an enhanced ability to retain calcium allowing them to survive on such low calcium diets. Results from this study indicate that, for anteaters in managed care, it is important to keep dietary calcium and vitamins D and K within recommended levels to prevent nutritional diseases such as hyper- and hypocalcemia and vitamin K deficiency.

Utilization of a zoo for mosquito (Diptera: Culicidae) diversity analysis, arboviral surveillance, and blood feeding patterns.

Zoos provide a unique opportunity to study mosquito feeding ecology as they represent areas where exotic animals, free-roaming native animals, humans, and mosquito habitats overlap. Therefore, these locations are a concern for arbovirus transmission to both valuable zoo animals and human visitors. We sampled mosquitoes in and around The Nashville Zoo at Grassmere in Tennessee, USA, over 4 months in 2020 using 4 mosquito trap methods and 12 sampling locations. Mosquitoes were identified to species, Culex mosquitoes were analyzed for arboviruses, and all engorged mosquitoes were preserved for host usage analysis. We captured over 9,000 mosquitoes representing 27 different species, including a new species record for Davidson County, TN (Culex nigripalpus Theobald). Minimum infection rates for West Nile virus (WNV) (Flaviviridae: Flavivirus), St. Louis encephalitis virus (Flaviviridae: Flavivirus), and Flanders virus (Hapavirus: Rhabdoviridae) were 0.79, 0, and 4.17, respectively. The collection of 100 engorged mosquitoes was dominated by Culex pipiens pipiens Linnaeus (38%), Culex erraticus Dyar and Knab (23%), and Culex pipiens pipiens-Culex pipiens quinquefasciatus hybrids (10%). Host DNA from 84 engorged mosquitoes was successfully matched to a variety of host species (n = 23), with just 8 species belonging to the zoo. Wild birds were the most frequently fed upon host, in particular northern cardinals (Cardinalis cardinalis L. Passeriformes: Cardinalidae), which are competent WNV reservoirs. Taken together, our results demonstrate the utility of zoos as sentinels for emerging pathogens, for studying wildlife and human risk of zoonotic diseases, and for assessing vector diversity.

West Nile Virus and Epizootic Hemorrhagic Disease Virus Co-Infection in a Novel Host at the Nashville Zoo.

On August 30, 2017, one of five bontebok in a mixed-species exhibit at the Nashville Zoo at Grassmere exhibited acute hind-limb ataxia and altered demeanor. Pathological examination demonstrated meningoencephalitis and spinal myelitis. Coinfection of West Nile virus (WNV) and epizootic hemorrhagic disease virus (EHDV) was revealed by quantitative real-time and traditional reverse transcription-polymerase chain reaction assays and virus isolation/whole genome sequencing from brain tissue, respectively. Whole genome sequencing was conducted for EHDV. Mosquito testing from September 19 to October 13, 2017, demonstrated a higher WNV infection rate in mosquitoes at the zoo compared with the rest of Nashville-Davidson County. EHDV is endemic in wild white-tailed deer (family Cervidae) in Tennessee, and the prevalence in wildlife depends on environmental influences. This case illustrates the potential susceptibility of exotic zoo animals to endemic domestic arthropod-borne viruses (arboviruses) and reinforces the importance of cooperative antemortem and postmortem surveillance strategies among human, wildlife, and domestic animal health agencies.

CAUSES OF MORTALITY AND COMORBIDITIES IN CAIMAN LIZARDS (DRACAENA GUIANENSIS) AT SIX ZOOLOGICAL INSTITUTIONS.

An understanding of the main causes of mortality in caiman lizards (Dracaena guianensis) under managed care is imperative to promote optimal husbandry, health, and welfare. A retrospective review of morbidity and mortality in caiman lizards from North American zoological institutions between 2005 and 2020 was conducted. Postmortem data, including gross necropsy and histopathology findings, were available for 32 caiman lizards (n = 12 subadults, n = 20 adults) from six zoological institutions. Necropsy reports were evaluated to collect general demographic data, categorize cause of death (accident/trauma, congenital/genetic, degenerative/geriatric, infectious, deposition disease, neoplastic, unknown, and multifactorial), and assess common comorbidities. Infectious disease was the most common cause of mortality in adult lizards (8/20; 40%) with amoebiasis and bacterial etiologies being overrepresented. Demise due to traumatic/accidental injury was the second most common cause of death in adult lizards (3/20;15%) and included blunt force trauma or suspected drowning. Infectious disease (4/12; 33.3%) and trauma/accidental injury (4/12; 33.3%) were also the most common causes of death in subadults. The most common comorbidities or other incidental findings identified during necropsy included trematode parasitism (15/32; 46.9%), arteriosclerosis (11/32; 34.4%), and adrenocortical hyperplasia (6/32; 18.8%). This retrospective review suggests that management practices to prevent and control infectious diseases and mitigate traumatic injury play a pivotal role in the long-term care and survival of caiman lizards in managed care.

COMPARISON OF TWO α2-ADRENERGIC AGONISTS ON URINE CONTAMINATION OF SEMEN COLLECTED BY ELECTROEJACULATION IN CAPTIVE AND SEMI-FREE-RANGING CHEETAH (ACINONYX JUBATUS).

Alpha2-adrenergic agonists are used to immobilize many veterinary species, but use has been infrequently linked to urine contamination of semen collected via electroejaculation. The objective of the study was to compare the α2-agonists medetomidine and dexmedetomidine on urine contamination of semen in anesthetized cheetahs (Acinonyx jubatus) during electroejaculation procedures. From 2009-2012, a retrospective medical record review revealed 21 anesthesia events in 12 adult male cheetahs. Animals were immobilized with combinations of Telazol® (2.33±0.43 mg/kg) and ketamine (2.38±1 mg/kg); Telazol (1.17±0.14 mg/kg), ketamine (1.17±0.14 mg/kg), and medetomidine (0.012±0.0017 mg/kg); or Telazol (1.59±0.1 mg/kg), ketamine (1.59±0.1 mg/kg) and dexmedetomidine (0.01±0.001 mg/kg). Semen was successfully collected in all animals; four animals anesthetized with medetomidine had urine contamination (P=0.037). Medetomidine may contribute to urine contamination; however, further investigation is needed to determine significance in cheetahs.

Retrospective analysis of mortalities in elephant shrews (Macroscelididae) and tree shrews (Tupaiidae) at the Smithsonian National Zoological Park, USA.

Investigations into the cause of mortality and other important findings at necropsy were made into two families of small mammals at the Smithsonian National Zoological Park (SNZP; USA). Necropsy reports from 1976 through 2008 were reviewed for all elephant shrews in family Macroscelididae (n = 118) and all tree shrews in family Tupaiidae (n = 90) that lived for greater than 30 days at the SNZP. Causes of mortality were classified by body system and etiology to identify prevalent diseases and trends across demographics for each family. In elephant shrews, gastrointestinal disease (n = 18) and respiratory disease (n = 22) were important causes of mortality with an increased prevalence of pneumonia in adult males. Trauma was a common cause of mortality in tree shrews (n = 22). Cryptococcosis was an important cause of mortality in both families (n = 8 elephant shrews; n = 13 tree shrews). Bacterial infections, often systemic at time of mortality, were also common (n = 16 elephant shrews; n = 17 tree shrews). Arteriosclerosis was a common comorbid pathology noted at necropsy in certain populations, seen only in Elephantulus rufescens in the family Macroscelididae (n = 22) and in only males in the family Tupaiidae (n = 11). Gongylonemiasis was seen commonly in tree shrews (n = 15), as a comorbid finding, or in 5 cases directly leading to mortality. Awareness of the prevalence of these diseases can help guide prevention and intervention strategies.

Embryonal rhabdomyosarcoma in a Rothschild's giraffe (Giraffa camelopardalis rothschildi).

Abstract: A 3-yr-old male Rothschild's giraffe (Giraffa camelopardalis rothschildi) presented for acute swelling caudomedial to the left parietal horn. Following initial diagnostics and supportive treatment, the mass was surgically resected and intralesional chemotherapy was administered. Despite treatment, the giraffe's condition worsened and euthanasia was performed. Gross necropsy revealed neoplastic invasion and destruction of underlying parietal bone, adjacent horn base, and sinuses, and metastases in the tracheobronchial and mandibular lymph nodes and lung. Histologically, the tumor was composed of packets of anaplastic round cells. Immunohistochemical studies further characterized the tumor as an embryonal rhabdomyosarcoma. This is the first reported case of rhabdomyosarcoma in a giraffe.