GLOBAL RETROSPECTIVE REVIEW OF SEVERE ACUTE RESPIRATORY SYNDROME SARS COV-2 INFECTIONS IN NONDOMESTIC FELIDS: MARCH 2020-FEBRUARY 2021.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in nondomestic felids have been documented in North America, South America, Africa, Europe, and Asia. Between March 2020 and February 2021, at nine institutions across three continents, infection was confirmed in 16 tigers (Panthera tigris), 14 lions (Panthera leo), three snow leopards (Panthera uncia), one cougar (Puma concolor), and one Amur leopard cat (Prionailurus bengalensis euptilurus) ranging from 2 to 21 yr old (average, 10 yr). Infection was suspected in an additional 12 tigers, 4 lions, and 9 cougars. Clinical signs (in order of most to least common) included coughing, ocular and/or nasal discharge, wheezing, sneezing, decreased appetite, lethargy, diarrhea, and vomiting. Most felids recovered uneventfully, but one geriatric tiger with comorbidities developed severe dyspnea and neurologic signs necessitating euthanasia. Clinical signs lasted 1-19 d (average, 8 d); one tiger was asymptomatic. Infection was confirmed by various methods, including antigen tests and/or polymerase chain reaction (PCR) of nasal or oral swabs, tracheal wash, and feces, or virus isolation from feces or tracheal wash. Infection status and resolution were determined by testing nasal swabs from awake animals, fecal PCR, and observation of clinical signs. Shedding of fecal viral RNA was significantly longer than duration of clinical signs. Postinfection seropositivity was confirmed by four institutions including 11 felids (5 lions, 6 tigers). In most instances, asymptomatic or presymptomatic keepers were the presumed or confirmed source of infection, although in some instances the infection source remains uncertain. Almost all infections occurred despite using cloth facemasks and disposable gloves when in proximity to the felids and during food preparation. Although transmission may have occurred during momentary lapses in personal protective equipment compliance, it seems probable that cloth masks are insufficient at preventing transmission of SARS-CoV-2 from humans to nondomestic felids. Surgical or higher grade masks may be warranted when working with nondomestic felids.

Detection of SARS-CoV-2 clade B.1.2 in three snow leopards.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is one of seven coronaviruses known to infect humans. Different from other concerned coronavirus and influenza viruses, SARS-CoV-2 has a higher basic reproduction number and thus transmits more efficiently among hosts. Testing animals for SARS-CoV-2 may help decipher virus reservoirs, transmission and pathogenesis. Here, we report the first detection of SARS-CoV-2 in three snow leopards (Panthera uncia) in a zoo in Kentucky in 2020, the first year of the pandemic. Sequence analysis revealed that snow leopard SARS-CoV-2 strains were non-variant B.1.2 lineage and closely correlated with human strains. One snow leopard shed SARS-CoV-2 in faeces up to 4 weeks. Based on clinical signs and viral shedding periods and levels in the three snow leopards, animal-to-animal transmission events could not be excluded. Further testing of SARS-CoV-2 in animals is needed.

The Adrenal Cortisol Response to Increasing Ambient Temperature in Polar Bears (Ursus maritimus).

Our objective was to identify the upper ambient temperature threshold that triggers an increase in cortisol in response to increased thermoregulatory demands in polar bears. The results reported here include endocrine data collected over two years from 25 polar bears housed in 11 accredited zoological institutions across North America. The effects of ambient temperature, sex, age group (juvenile, adult, elderly), breeding season and humidity on fecal cortisol metabolite (FCM) concentrations (N = 8439 samples) were evaluated using linear mixed models. Ambient temperatures were placed into five different categories: <5 °C, 6−10 °C, 11−15 °C, 16−20 °C, and >20 °C. Ambient temperature and humidity had a significant (p < 0.05) effect on FCM concentrations with significant (p < 0.05) interactions of sex, age and breeding season. Once biotic factors were accounted for, there was a significant (p < 0.05) increase in FCM concentrations associated with ambient temperatures above 20 °C in adult polar bears. The implications of these findings for the management of both zoo and wild polar bears are discussed.

A Retrospective Study of Pathology in Bats Submitted to an Exotic and Zoo Animal Diagnostic Service in Georgia, USA (2008-2019).

Pathology records of bats submitted to the University of Georgia from managed care settings were reviewed to identify naturally occurring diseases. Fifty-nine cases were evaluated during an 11-year period (2008-2019), including representatives from four families: Pteropodidae (Yinpterochiroptera), Phyllostomidae, Vespertilionidae and Molossidae (Yangochiroptera). Pathology reports were reviewed to determine the primary pathological process resulting in death or the decision to euthanize. Cases were categorized as non-infectious (34/59; 58%), infectious/inflammatory (17/59; 29%) or undetermined due to advanced autolysis (8/59; 14%). Musculoskeletal diseases and reproductive losses were the most frequent pathological processes. Among the infectious processes identified, bacterial infections of the reproductive and haemolymphatic systems were most frequently observed. The first two reports of neoplasia in small flying foxes (Pteropus hypomelanus) are described. Bats under managed care present with a wide range of histopathological lesions. In this cohort, non-infectious disease processes were common.

REVIEW OF CANINE DISTEMPER VACCINATION USE AND SAFETY IN NORTH AMERICAN CAPTIVE LARGE FELIDS (PANTHERA SPP.) FROM 2000 TO 2017.

Data on canine distemper virus (CDV) vaccination were collected on 812 large felids (351 tigers, Panthera tigris; 220 lions, Panthera leo; 143 snow leopards, Panthera uncia; 50 leopards, Panthera pardus; and 48 jaguars, Panthera onca) from 48 institutions to assess vaccine use and safety. The documented individual vaccination events with multiple products numbered 2,846. Canarypox-vectored CDV vaccines were the most commonly used vaccines (96.3% of all vaccinations) and the Purevax® Ferret Distemper (PFD) vaccine was the most commonly used canarypox-vectored vaccine (91.0% of all vaccinations). Modified live virus (MLV) CDV vaccines were used for 3.7% of all vaccinations, and only in tigers, lions, and snow leopards. Adverse effects were reported after 0.5% (13 of 2,740) of the canarypox-vectored vaccinations and after 2.9% (3 of 104) of the MLV CDV vaccinations. This low complication rate suggests large felids may not be as sensitive to adverse effects of MLV CDV vaccines as other exotic carnivores. Serological data were available from 159 individuals (69 tigers, 31 lions, 31 snow leopards, 22 jaguars, and 6 Amur leopards, Panthera pardus orientalis) vaccinated with the PFD vaccine, and 66.0% of vaccinates seroconverted (defined as acquiring a titer ≥1: 24) at some point postvaccination: 24.3% after one vaccination, 55.8% after two vaccinations, 54.3% after three vaccinations, and 79.2% after four or more vaccinations. Among animals exhibiting seroconversion after the initial PFD vaccinations, 88.9% still had titers ≥12 mo and ≥24 mo after the last vaccination, and 87.5% had titers ≥1: 24 at ≥36 mo after the last vaccination. The study was unable to assess fully the safety of vaccination with either canarypox-vectored or MLV CDV vaccines during gestation because of the small number of animals vaccinated while pregnant (n = 6, all vaccinated with PFD).

Fatal Sarcocystis falcatula Infection in Three Penguins.

Sarcocystis falcatula is a well-known cause of fatal pneumonia in some birds, particularly Old World psittacines. Here we describe fatal sarcosystosis due to S. falcatula in 3 penguins (Family Spheniscidae) under managed care, including one African penguin (Spheniscus demersus), and two Southern rockhopper penguins (Eudyptes chrysocome). Randomly distributed foci of necrosis, inflammatory cell infiltrates, edema, and variable numbers of round to elongated protozoal schizonts were observed in sections of lung. Protozoal organisms exhibited strong immunoreactivity for Sarcocystis sp. antigen by immunohistochemistry. Apicomplexan and Sarcocystis genus-specific PCR assays and sequence analysis confirmed S. falcatula as the etiologic agent. These cases of fatal pneumonia attributed to S. falcatula expand the list of aberrant intermediate avian hosts, with particular implications for penguins.

ENCEPHALITOZOON CUNICULI INFECTION IN A BLACK-FOOTED FERRET (MUSTELA NIGRIPES) KIT.

A 47-day-old black-footed ferret (Mustela nigripes) kit was found dead in June 2016. Histologic examination revealed pyogranulomatous tubulointerstitial nephritis, pneumonia, and encephalitis, with intralesional microsporidia. Transmission electron microscopic examination showed microsporidia with ultrastructural characteristics consistent with Encephalitozoon spp. Polymerase chain reaction (PCR) and direct sequencing confirmed the presence of Encephalitozoon cuniculi genotype II. This organism has been reported in other Carnivora (i.e., canids, felids, mustelids, procyonids, otariids). In humans, it is generally described as an opportunistic pathogen in immunocompromised individuals. The source of infection in the quarantine facility remains unknown, although two groups of frozen feeder rat kidneys tested positive for E. cuniculi genotype II via PCR. Feeding whole prey to various zoo taxa carries some potential disease transmission risk.

CUTANEOUS T-CELL LYMPHOMA WITH LYMPH NODE METASTASIS IN AN ADULT ADDAX (ADDAX NASOMACULATUS).

A 13-yr-old male addax (Addax nasomaculatus) presented with locally extensive alopecia, slight erythema, and skin thickening on the medial aspect of the left rear leg between the stifle and tarsus. Cutaneous T-cell lymphoma was diagnosed after histopathology and immunohistochemical staining of representative skin-punch biopsies. No treatment was elected, and the addax was euthanized 3 yr later because of poor body condition, chronic dental disease, and confirmed spread of lymphoma to other cutaneous locations. Postmortem evaluation revealed spread to multiple lymph nodes but no further organ metastasis. Serologic testing on archived serum for bovine leukemia virus (BLV) revealed no evidence of exposure or infection. In cattle, cutaneous lymphoma is a sporadic form of lymphoma that is relatively rare, not typically associated with BLV infection, and occurs in young animals (<3 yr). This is the first report of cutaneous lymphoma in a nondomestic bovid.

ACUTE CLINICAL LEPTOSPIROSIS (GRIPPOTYPHOSA SEROVAR) IN AN ADULT DROMEDARY CAMEL (CAMELUS DROMEDARIUS).

A 9-yr-old castrated male dromedary camel (Camelus dromedarius) presented with lethargy and partial anorexia. A diagnostic examination revealed fever, and further workup revealed a neutrophilia, hyperfibrinogenemia, renal azotemia, and a rapid onset of a high Leptospira antibody titer during the acute clinical period (Grippotyphosa serovar). The camel responded clinically to antimicrobial treatment with ceftiofur crystalline free acid injections, but renal azotemia persisted, presumably secondary to chronic renal damage. Subsequent Leptospira polymerase chain reaction testing on urine samples obtained over the following 4 mo revealed no evidence of urinary shedding, so a persistent infection was unlikely. Although often mentioned as a potential cause of reproductive loss, well-documented case reports of clinical leptospirosis in camelids are very rare. In this case, native wildlife contamination of a small watering hole is suspected to have been the source of infection. In response to this experience, the camel and two conspecifics were prescribed a vaccination regimen using an inactivated pentavalent Leptospira vaccine licensed for cattle.

Ovariectomy due to a dermoid cyst in an orangutan (Pongo pygmaeus).

A large abdominal mass was identified during an elective preventative health examination in a 25-yr-old female hybrid orangutan (Pongo pygmaeus). Sonographically, the mass was fluid-filled and a presumptive diagnosis of a dermoid cyst or cystic teratoma of an ovary was made. Exploratory laparotomy, after assembly of a surgical team, confirmed that the 2.5-kg cystic mass was associated with the left ovary. Following ovariectomy, perioperative dissection of the mass revealed hair components, confirming the working diagnosis. Because the right ovary was slightly nodular and firmer than expected, and these germ cell tumors sometimes occur bilaterally, excision of the contralateral ovary was elected. Histopathology confirmed the left ovarian mass was a dermoid cyst; the right ovary contained a corpus hemorrhagicum but no evidence of neoplasia. Recovery was uneventful and the orangutan was prescribed hormone replacement therapy to mitigate potential problems associated with a chronic lack of estrogen and progesterone. This case report demonstrates the importance of elective examinations under anesthesia, even in well-trained great apes.

Abomasal impaction in captive bongo (Tragelaphus eurycerus).

Fatal abomasal impaction, often combined with omasal impaction, was diagnosed in 11 bongo (Tragelaphus eurycerus) from five different zoologic collections in the United States between 1981 and 2009. Nine of 11 cases occurred in young females (10 mo-7 yr old) and typical clinical signs prior to diagnosis or death included partial or complete anorexia, dehydration, and scant fecal production. Although the clinical histories in several of the earlier cases are incomplete, clinical signs were known to begin shortly after an anesthetic event in five of 11 bongo (45%). Pedigree analysis indicates that affected bongo were descendants of multiple founders and not from a single family line, suggesting that the development of abomasal impaction is not a strictly inheritable trait. Treatment, when attempted, was variable and included abomasotomy and removal of impacted ingesta, drug therapy (prokinetic drugs, nonsteroidal anti-inflammatories, antimicrobials), fluid therapy, and administration of oral lubricants or intralesional stool softeners. Based on the outcomes in the cases presented here, the prognosis for bongo with abomasal impaction is considered poor to grave.

PCR detection of ranavirus in adult anurans from the Louisville Zoological Garden.

Ranaviruses are known to cause mortality in a variety of anuran species and have the potential to significantly impact wild and captive frog populations. In this study, 16 captive frogs and toads from the Louisville Zoological Garden were examined for the presence of ranavirus; this group included 14 Cope's grey tree frogs (Hyla chrysoscelis), an American toad (Bufo americanus), and a southern toad (Bufo terrestris). All animals were wild caught and were evaluated via polymerase chain reaction (PCR), while animals that died were also assessed via histologic study to understand the role of ranaviral disease in these specimens. Of the animals that died, 82% were positive for ranavirus via PCR. Multiple swab samples collected over time from live tree frogs were positive for ranavirus via PCR. These findings reveal that ranaviral infection in captive adult anurans may occur without clinical signs or consistent histopathologic lesions.

Presumptive benzocaine-induced methemoglobinemia in a slender-tailed meerkat (Suricata suricatta).

An 8-yr-old castrated male slender-tailed meerkat (Suricata suricatta) was anesthetized for physical examination and dental prophylaxis. To facilitate intubation, two short bursts of benzocaine spray were applied topically to the glottis. Shortly thereafter, the meerkat developed a muddy, blue-gray mucous membrane color and low oxygen saturation readings measured via pulse oximetry. Despite positive pressure ventilation and treatment with doxapram, the cyanosis and hypoxemia did not improve. Blood collected during the procedure was noticeably dark brown and a clinical diagnosis of methemoglobinemia was made. Because of persistent cyanosis and prolonged recovery, the meerkat was anesthetized a second time to facilitate treatment for methemoglobinemia via a slow intravenous bolus of methylene blue and subcutaneously administered dextrose. Within 20 min, the tongue and gingival color normalized. This is the first report of methemoglobinemia in this species. Although it is commonly used in small animal practice and in humans undergoing certain endoscopic procedures, and present in numerous over-the-counter preparations, the risk of topical benzocaine inducing methemoglobinemia is well described. Administration of topical benzocaine in all mammalian species, particularly small patients, should be done with caution. If it is utilized in zoo practice, clinicians are encouraged to administer benzocaine judiciously to avoid accidental overdose, and be familiar with the signs of methemoglobinemia and its treatment.

Management of chronic vaginal prolapse in an eastern bongo (Tragelaphus eurycerus isaaci).

A 4.5-yr-old multiparous female eastern bongo (Tragelaphus eurycerus isaaci) presented with a prolapsed vagina 4 mo after dystocia and vaginal extraction of a large calf. The prolapse was corrected via manual reduction and vulvoplasty (Caslick operation). A melengesterol acetate contraceptive implant was placed and the bongo was asymptomatic for 6 yr until vaginal prolapse recurrence. The vaginal prolapse recurred four times over a 2-yr span and was managed with repeat Caslick procedures and several epidural injections using 95% grain alcohol. Complications secondary to long-term progestin implant usage, acquired urovagina, as well as perineal atony from the alcohol epidurals are believed to have contributed to prolapse recurrence. Ovariohysterectomy and vaginoplasty ultimately were elected and were curative. According to a survey conducted in response to this case, obstetrical issues and female reproductive tract problems appear to occur sporadically in captive bongo but are not uncommon.

Spontaneous neoplasia in four captive greater hedgehog tenrecs (Setifer setosus).

Little information is available about diseases and pathology of species within the family Tenrecidae, including the greater hedgehog tenrec (Setifer setosus), a Madagascan insectivore. This report summarizes necropsy and histopathologic findings of neoplasia in four captive greater hedgehog tenrecs. Although only four animals are included in this report, neoplasia seems to be a common and significant source of morbidity and mortality in greater hedgehog tenrecs. Types of neoplasia identified include a thyroid follicular-solid carcinoma, two urinary bladder transitional cell carcinomas, uterine endometrial polyps, and multicentric B-cell lymphoma. Due to small sample size, no etiology could be determined, but genetics, viral infection, pesticide treatment, nutrition, or other environmental factors might contribute to the development of neoplasia in this species. This is the first report of neoplasia in greater hedgehog tenrecs.

Sticktight flea (Echidnophaga gallinacea) infestation in a Victoria crowned pigeon (Goura victoria).

A 12-yr-old female Victoria crowned pigeon (Goura victoria), acquired from a private aviculturalist, was diagnosed with a flea infestation during a quarantine examination. The fleas were embedded around the face and throat and were identified as sticktight fleas (Echidnophaga gallinacea). Despite the sticktight fleas' worldwide distribution and broad host range, there is a paucity of reports on flea infestations and their treatment in zoo and exotic pet birds. Although this parasite has the potential to induce morbidity and mortality, no feather loss, localized dermatitis, or anemia was noted in response to the ectoparasitism. The infestation was treated with manual removal of fleas combined with topical malathion dusting and environmental treatment. Subsequent recheck exams did not reveal any fleas on this pigeon or on any of the other birds housed in the same room. This case illustrates the importance of quarantine procedures for newly acquired birds as part of responsible captive management of a large, multispecies bird collection.

Application of assays for the diagnosis of toxoplasmosis in a colony of woolly monkeys (Lagothrix lagotricha).

Toxoplasma gondii infection is a common cause of morbidity and mortality in New World primate species. Clinical abnormalities associated with toxoplasmosis can be nonspecific, making it difficult to make a definitive antemortem diagnosis and initiate appropriate treatment. Toxoplasmosis in New World primates can have a rapid clinical course, which may lessen the diagnostic utility of antemortem tests. However, while there are a variety of T. gondii serum antibody tests and T. gondii polymerase chain reaction (PCR) assays available that are not species specific, these assays have not been comparatively applied to New World primate cases. Woolly monkeys (Lagothrix lagotricha), a species of New World primate, are highly susceptible to fatal toxoplasmosis. Archived serum samples from 15 living and deceased woolly monkeys housed at the Louisville Zoological Garden (Louisville, Kentucky) were tested for T. gondii antibodies by a commercially available latex agglutination kit, a commercially available indirect hemagglutination kit, and the modified agglutination test. In addition, aliquots of the sera were assayed for T. gondii DNA using a PCR assay. Both woolly monkeys that died of disseminated toxoplasmosis were positive in all four assays, indicating that each could be used to aid in the diagnosis of toxoplasmosis in this species. We suspect that these assays have applications to other species of New World primates.

High incidence of lymphoid neoplasia in a colony of Egyptian spiny-tailed lizards (Uromastyx aegyptius).

Hematopoietic malignancies are the most commonly reported neoplasms in lizards, occurring sporadically as in other reptiles. An unusually high incidence of lymphoid neoplasia occurred in a collection of Egyptian spiny-tailed lizards (Uromastyx aegyptius) from 1993-2001. Eight of 15 lizards necropsied at the Louisville Zoological Garden (53%) had multicentric lymphoma. Immunohistochemistry was not useful in characterizing the lineage of normal or neoplastic lymphocytes. By light and electron microscopy (EM), the neoplasms had plasmacytoid morphologic features suggesting B-cell origin, although some tumors also had a primitive lymphoblast component. A concurrent leukemic blood profile was identified in seven of the cases (88%). All were adult animals and no sex predilection was observed. No exposure to exogenous carcinogens was observed. Some of the lizards were unrelated, so hereditary factors were unlikely. Although examination by EM and viral isolation performed on archived tissues and plasma failed to detect viruses, an infectious etiology still warrants consideration.