Nondomestic Felids Research Articles

ABCG2 Polymorphisms and Predictive Fluoroquinolone Phototoxicity in Nondomestic Felids

Fluoroquinolones are a widely used class of chemotherapeutics within veterinary medicine, prized for their broad-spectrum bactericidal activity. These drugs present a known risk of retinal phototoxicity in domestic cats (Felis catus); therefore, using lower doses and alternative antibiotic classes is encouraged in this species. This adverse drug effect of fluoroquinolones, and enrofloxacin specifically, has been determined to be species-specific in domestic felids. Four feline-specific missense variants in ABCG2 result in four amino acid changes (E159M, S279L, H283Q, and T644I) that are unique to the domestic cat compared with multiple other nonfeline mammalian species. These changes alter the ABCG2 protein involved with the cellular transmembrane transport of drugs, including fluoroquinolones, making the protein functionally defective in domestic cats. The predisposition to fluoroquinolone-mediated phototoxicity in nondomestic felids was explored in this study. At least eight nondomestic felids share the four ABCG2 missense variants with domestic cats, and eleven other felids shared at least three of the four domestic cat variants. Taken together, these results suggest the genetic potential for nondomestic felids to also experience fluoroquinolone-induced retinal phototoxicity; therefore, cautions similar to those for domestic cats should be followed for these drugs in the entire feline taxon.

Generation and cryopreservation of feline oviductal organoids

Next-generation in vitro culture model systems are needed to study the reproductive pathologies that affect domestic animals. These 3D culture models more closely mimic normal physiological function to allow a greater understanding of reproductive pathology and to trial therapeutics without the welfare concerns and the increased time and cost associated with live animal research. Recent advances with in vitro cell culture systems utilizing human and laboratory animal tissues have been reported, but implementation of these technologies in veterinary species has been slower. Organoids are a physiologically representative 3D cell culture system that can be maintained long-term. By combining organoid culture with cryopreservation, a long-term, experimental model can be available for year-round application, thus bypassing seasonality and reproductive tract availability restrictions. Here we report the generation and cryopreservation of feline oviductal organoids for the first time. Optimal culture medium for the generation of feline oviductal organoids was established, and organoids were successfully cryopreserved using three different freezing media with organoids from each treatment demonstrating comparable viability, growth rate, and protein expression after thawing and culture. Feline oviductal organoids may facilitate an in vivo-like environment that, in conjunction with co-culture for in vitro maturation and in vitro fertilization, may positively influence in vitro gamete and embryo development, embryo quality, and pregnancy rates after embryo transfer in domestic and nondomestic felids. Furthermore, readily available cryopreserved feline oviductal organoids will facilitate this co-culture, which is of particular importance to endangered felid breeding programs where tissue and gamete samples are often opportunistically obtained with little or no notice.

YERSINIA PSEUDOTUBERCULOSIS INFECTION IN LIONS (PANTHERA LEO) AT A ZOOLOGICAL PARK.

Two co-housed 17-yr-old male lions (Panthera leo) and one 15-yr-old female lion in an adjacent enclosure developed acute lethargy, depression, anorexia, and ataxia at a zoological park in central North Carolina, United States. One of the male lions and the female lion were found dead 5 and 4 d after the onset of clinical signs, respectively. The other male lion recovered without any clinical treatment. A third male lion housed with the female lion never developed clinical signs. Postmortem examination, microscopic evaluation, and bacterial culture of the liver from both deceased lions confirmed systemic Yersinia pseudotuberculosis infection. Susceptibility testing revealed resistance to amoxicillin-clavulanic acid and cefazolin. To investigate the extent of the outbreak, qualitative real-time polymerase chain reaction (PCR) for Y. pseudotuberculosis was performed on feces and substrate from 15 enclosures housing nondomestic felids and canids, resulting in a positive sample from one enclosure housing four asymptomatic lions. This enclosure was adjacent to housing of the deceased female lion. Enrofloxacin was administered to all animals in the vicinity at doses of 5 mg/kg in nondomestic felids and 10 mg/kg in nondomestic canids, orally q24h for 14 d. Repeated fecal PCR performed 1 wk after completing the antibiotic treatment protocol found no positive samples. The source of the infection was not identified despite PCR testing of environmental samples from all enclosures in the vicinity, the remains of a prey item fed out prior to the outbreak, and a single dead rodent found on grounds. No further clinical cases have occurred within the following year.

Molecular Detection of Feline Coronavirus in Captive Non-Domestic Felids from Zoological Facilities.

Simple SummaryNon-domestic felids are well-known threatened species, and are susceptible to several diseases that also affect domestic cats. Among viral infections, fatal outbreaks of feline infectious peritonitis, caused by a feline coronavirus, have been reported in captive settings. Considering the devastating effects that this pathogen could have in non-domestic felids, the aim of this study was to assess the prevalence of feline coronavirus in captive non-domestic felids from Northern Italy, since in the literature, this information is not currently available. The overall prevalence of feline coronavirus in captive non-domestic felids from Northern Italy was 7.9%. Results of the present study highlight the need of control programs for feline coronavirus infection to prevent pathogen introduction into a naïve group of animals, which may lead to devastating effects on animal welfare and conservation programs.Cases of feline infectious peritonitis (FIP), a disease with a high mortality rate caused by the feline coronavirus (FCoV), have been reported in non-domestic felids, highlighting the need for surveys of FCoV in these endangered species. With the aim of adding information on FCoV prevalence in captive non-domestic felids, samples (feces or rectal swabs and, when available, oral swabs, blood, and abdominal effusion) collected between 2019 and 2021 from 38 non-domestic felids from three different zoological facilities of Northern Italy were tested for evidence of FCoV infection via RT-qPCR. Three animals were found to be FCoV positive, showing an overall 7.9% FCoV prevalence ranging from 0% to 60%, according to the zoological facility. FCoV infection was detected in tiger cubs of the same litter, and all of them showed FCoV-positive oral swabs, with low viral loads, whereas in one animal, FCoV presence was also detected in rectal swabs at low FCoV copy numbers. Future studies should be carried out, including samplings from a higher number of captive non-domestic felids, in order to gain a deeper knowledge of FCoV epidemiology within these populations.

Detection of Multiple Hepatic Peribiliary Cysts in Captive Lions (Panthera leo)

Background: Hepatic lesions in non-domestic felids are poorly characterized. The present study reports multiple hepatic peribiliary cysts in 9 out of 32 lions (Panthera leo) at Bannerghatta Biological Park, Bengaluru. Methods: The animals were presented for necropsy after the history of clinical signs of lethargy, anorexia, weakness, debilitated body conditions and all animals are in old age (between 15 to 25 years old). Systematic necropsy with gross and histopathological examination was carried out. Result: Post-mortem examination grossly revealed multiple cysts in liver (varying in each case) with the cystic masses filled with clear fluid, sometimes mixed with bile. A diagnosis for the presence of spontaneous peribiliary cysts was made on the basis of gross and microscopic lesions. Histologically, the cysts were surrounded and composed of compact collagenous tissue. The inner cystic single layer resembled biliary mucosa and composed of columnar epithelial lining, while the submucosa was composed of connective tissue with loss of hepatic cord structure.

Endometrial hyperplasia and pyometra in captive lions (Panthera leo) and tigers (Panthera tigris).

Endometrial hyperplasia (EH) is a pathologic condition of the uterus with increased endometrial gland to stroma ratio compared to normal cyclic uterine proliferation. In domestic animals, EH often involves cystic distension of proliferating endometrial glands and may be concurrent with pyometra. In large captive nondomestic felids, an association between EH and pyometra is common; however, detailed species differences between the histological uterine findings in lions (Panthera leo) and tigers (Panthera tigris) and clinical manifestations have yet to be described. Uterine sections from 14 lions and 24 tigers with EH and/or pyometra were scored for several histological parameters and clinical histories were recorded. The percentage of endometrium affected by hyperplasia, endometrial gland to stroma ratio, and adenomyosis were significantly (P = .0385, P = .0008, and P = .0463, respectively) more severe in lions compared to tigers as univariate analytes. Although tubular complexity was not statistically significant (P = .3254), when combined as a proposed EH grading scheme, these 4 features confirmed lions had significantly (P = .0068) more severe EH compared to tigers. Endometrial hyperplasia severity significantly correlated with inflammation/pyometra severity when controlling for species (P = .0203). A significant correlation exists between pyometra-associated clinical sign severity and the presence of pyometra in tigers, (P = .0026) but not in lions (P = .1144). There was no statistical difference in the severity of clinical signs associated with pyometra between these species (P = .1986). This proposed grading scheme may have clinical utility in providing a more consistent and objective evaluation of EH in large captive felids.

METHOD COMPARISON FOR MEASUREMENT OF SYMMETRIC DIMETHYLARGININE IN TIGERS (PANTHERA TIGRIS).

Renal disease is well documented in nondomestic felids and is monitored and diagnosed by serum concentration of blood urea nitrogen, creatinine, and phosphorous. Symmetric dimethylarginine (SDMA) has proven to be an earlier and more sensitive biomarker for the assessment of glomerular filtration rate. Although SDMA is commonly measured in nondomestic felids, information concerning the validity of the assay is lacking. The purpose of the study was to perform a method comparison between high-throughput immunoassay and the reference method, liquid chromatography-tandem mass spectrometry (LC-MS/MS), to quantify SDMA concentrations in tiger blood samples. Concentrations of SDMA were measured for 81 individual tiger samples. The SDMA immunoassay demonstrated excellent correlation to the LC-MS/MS reference method. A Passing and Bablok linear regression analysis had a slope of 1.03 (95% CI, 0.99-1.11), an intercept of 1.64 (95% CI, 0.46-2.34), and a Pearson R= 0.99. The mean bias was 1.53 µg/dl (95% CI, 0.63-2.42 µg/dl), and the limit of agreement was ±7.96 µg/dl. The degree of bias is within established acceptance criteria of 1-3 µg/dl for the immunoassay. Although this study provides good evidence of the utility of the immunoassay to measure SDMA in tiger serum and plasma, further assay validation is recommended.

DETECTION OF VECTOR-BORNE INFECTIONS IN LIONS AND TIGERS AT TWO ZOOS IN TENNESSEE AND OKLAHOMA, USA.

Protozoal and bacterial vector-borne infections are frequently diagnosed in domestic felids. However, with the exception of Mycoplasma haemofelis and Cytauxzoon felis, their occurrence in managed nondomestic felids housed in the United States is largely unknown. Following a case in February 2020 of fulminant cytauxzoonosis in an African lion (Panthera leo), EDTA-whole blood samples were collected opportunistically from February 2020 through June 2020 from 34 adult tigers (Panthera tigris) and eight adult African lions from the same sanctuary in eastern Tennessee as well as 14 adult tigers from a zoo in southern Oklahoma. Samples were analyzed for Cytauxzoon felis, Bartonella spp., hemotropic Mycoplasma, Rickettsia spp., Anaplasma spp., Ehrlichia spp., Babesia spp., and Hepatozoon spp. DNA by PCR amplification. All animals were asymptomatic at the time of collection. None of the Oklahoma animals were positive for vector-borne organisms, but these pathogens were detected in tigers at the Tennessee facility, including Cytauxzoon felis (11.8%), "Candidatus Mycoplasma haemominutum" (5.9%), and Ehrlichia ewingii (2.9%). During the study period, two animals developed clinical signs of cytauxzoonosis and were assessed for vector-borne infections as part of their diagnostic evaluation. This study documents the presence of tick-borne diseases in managed nondomestic felids in the southeastern United States and underscores that ectoparasite control measures should be practiced to minimize exposure of carnivores in managed care.

Magnetic Resonance Imaging in 50 Captive Non-domestic Felids - Technique and Imaging Diagnoses.

Magnetic resonance imaging (MRI) is the recognized gold standard for diagnostic imaging of the central nervous system in human and veterinary patients. Information on the use of this modality and possible imaging abnormalities in captive non-domestic felids is currently limited to individual case reports or small case series. This retrospective study provides information on technique and imaging findings in a cohort of cases undergoing MRI at an academic Veterinary Medical Center. The University of Tennessee College of Veterinary Medicine MRI database was searched for non-domestic felids undergoing MRI of the brain or spine from 2008 to 2021. Medical record data were recorded, and MRI studies were reviewed. Fifty animals met the inclusion criteria. The most common brain diseases were Chiari-like malformation (n = 8) and inflammatory conditions (n = 8). Other abnormalities included pituitary lesions (n = 5), brain atrophy (n = 2), and one each of metabolic and traumatic conditions. Fourteen animals had a normal brain MRI study. The most common spinal abnormality was intervertebral disc disease (n = 7). Other disorders included vertebral dysplasia (n = 2), presumptive ischemic myelopathy (n = 1), subdural ossification causing spinal cord compression (n = 1), and multiple myeloma (n = 1). Spinal cord swelling of undetermined cause was suspected in two animals, and seven patients had a normal MRI study of the spine. MRI is a valuable tool in the diagnostic workup of non-domestic felids with presumptive neurologic disease.

DURATION OF ANTIGEN SHEDDING AND DEVELOPMENT OF ANTIBODY TITERS IN MALAYAN TIGERS (PANTHERA TIGRIS JACKSONI) NATURALLY INFECTED WITH SARS-CoV-2.

Natural infection of three captive Malayan tigers (Panthera tigris jacksoni) with SARS-CoV-2 caused mild to moderate symptoms of lethargy, anorexia, and coughing. Each tiger was longitudinally sampled opportunistically via consciously obtained oral, nasal, and/or fecal samples during and after resolution of clinical signs, until 2 wk of negative results were obtained. Persistent shedding of SARS-CoV-2 genetic material was detected via reverse transcription-polymerase chain reaction in feces up to 29 d after initial onset of clinical signs, but not in nasal or oral samples. Tigers became resistant to behavioral training to obtain nasal samples but tolerated longitudinal oral sampling. Serum was obtained from two tigers, and antibody titers revealed a robust antibody response within 9 d of onset of clinical signs, which was sustained for at least 3 mon. The tigers were infected despite the use of masks and gloves by husbandry personnel. No known cause of the outbreak was identified, despite extensive investigational efforts by the regional health department. No forward cross-species transmission was observed in primates housed in nearby enclosures. The increasing regularity of reports of SARS-CoV-2 infection in nondomestic felids warrants further investigations into shedding and immunity.

A RETROSPECTIVE STUDY OF BRAIN LESIONS IN CAPTIVE NONDOMESTIC FELIDS.

This retrospective study identified and characterized brain lesions in captive nondomestic felids from a large cat sanctuary. Necropsy reports from January 2002 through December 2018 were examined, and gross images and microscopic slides were reviewed from individual cats, where available. In total, 255 cats met the following inclusion criteria: complete necropsy report available, brain examined grossly or microscopically, and age of >1 mon. Of the 255 cats, 49 cats (19%) were determined to have brain lesions. Eleven different felid species, as well as one captive-bred hybrid (liger), were included in the study, with tigers (Panthera tigris) (55%) and lions (Panthera leo) (18%) being the most common species. Lesions were grouped into six etiologic categories: neoplastic (32%), vascular (26%), inflammatory or infectious (20%), congenital (9%), idiopathic (7%), and metabolic (6%). Not included in these categorized lesions were previously undescribed amphophilic globules in the cerebral cortex of many cats with and without other brain lesions; these were in 95% of lion and 93% of tiger brains where the cerebral cortex was available for histologic examination. These globules were not associated with clinical disease. The histopathologic and gross brain changes documented in this study provide insight into specific diseases and pathologic processes that affect the brains of captive large cat populations.

Prevalence and type of ocular disease in a population of aged captive nondomestic felids.

Report of prevalence and type of ocular disease in a captive population of nondomestic felids. Medical records of 202 cats from 1993 to 2018 were reviewed. Species, age at diagnosis, sex, ocular examination abnormalities, systemic/physical examination abnormalities, type of examination (visual, sedated, or anesthetized), ocular structures affected, other diagnostics, therapy, and resolution of ocular disease were recorded. A total of 202 nondomestic felids including 18 different species (bobcat, caracal, cougar, Fishing cat, Geoffroy's cat, jaguar, jungle cat, leopard, leopard cat, liger, lion, lynx, ocelot, Sand cat, Savannah cat, serval, snow leopard, and tiger) from a rescue facility were evaluated. Forty-six ocular lesions were diagnosed in 33 (16.3%) cats from 8 different species (bobcat, caracal, cougar, leopard, lion, ocelot, serval, and tiger) with a mean age of 16±5.9years at time of diagnosis. Ocular lesions included corneal disease (37%) (ulcerations, perforations, keratitis, corneal scars), cataracts (23.9%), hyphema (8.7%), lens luxation (6.5%), retinal detachment (6.5%), uveitis (4.3%), conjunctival disease (4.3%), retinal degeneration (2.1%), glaucoma (2.1%), and optic neuritis (2.1%). Therapies included medical (topical antibiotics, anti-inflammatories, serum, etc.) and/or surgical management (enucleation, intracapsular lens extraction, corneoconjunctival transposition, and corneal burr debridement). To the authors' knowledge, this is the first report of the prevalence of ocular disease in a population of captive nondomestic felids. It is difficult to diagnose and treat ocular disease in nondomestic cats due to challenges related to handling, diagnostics, and therapeutics in nondomestic species. Ocular disease seen in this population is similar to that found in domestic cat populations.

A RETROSPECTIVE STUDY OF NEOPLASIA IN NONDOMESTIC FELIDS IN HUMAN CARE, WITH A COMPARATIVE LITERATURE REVIEW.

This retrospective study of neoplasia in nondomestic felids in human care presents the cases diagnosed at Northwest ZooPath (NWZP), Monroe, Washington, from 1998 to 2017 in conjunction with a scoping literature review. The 554 neoplasms identified in 20 species in the NWZP archive were combined with the 984 neoplasms identified in those same species in the published literature. Some of the cases identified in the literature were from the NWZP archive. Based on this review, mammary adenocarcinoma (183/1,483, 12.3%), lymphoma (89/1,483, 6.0%), squamous cell carcinoma (85/1,483, 5.7%), pheochromocytoma (57/1,483, 3.8%), and thyroid adenoma (57/1,483, 3.8%) are the most frequently reported neoplasms in nondomestic felids in human care. Apparent species predilections for neoplasia include mammary adenocarcinoma in tigers, jaguars, lions, and jungle cats; lymphoma in lions and tigers; squamous cell carcinoma in snow leopards; pheochromocytoma in clouded leopards; ovarian adenocarcinoma in jaguars; cholangiocarcinoma in lions and tigers; multiple myeloma in tigers; bronchoalveolar adenocarcinoma in cougars and lions; hemangiosarcoma, hepatocellular carcinoma, and gastrointestinal adenocarcinoma in lions; mesothelioma in clouded leopards, lions, and tigers; myelolipoma and cutaneous mast cell tumor in cheetahs; soft tissue sarcomas in tigers; and transitional cell carcinoma of the urinary bladder in fishing cats.

COMPARISON OF BLOOD SYMMETRIC DIMETHYLARGININE AND CREATININE AS ENDOGENOUS MARKERS OF KIDNEY FUNCTION IN CAPTIVE TIGERS (PANTHERA TIGRIS).

Chronic kidney disease (CKD) is a common cause of morbidity and mortality in captive tigers (Panthera tigris). Blood creatinine (Cr) and blood urea nitrogen measurements are inexpensive and common biomarkers used to evaluate renal function. However, several limitations have been reported regarding their sensitivity and interindividual variability. Symmetric dimethylarginine (SDMA) has been suggested to be a more sensitive biomarker that is less affected by extrarenal factors and has a strong correlation with glomerular filtration rate and blood Cr in several species. This project aimed to identify the usefulness of SDMA as an endogenous marker of kidney function in captive tigers. The hypothesis of this study is that increased circulating SDMA is positively associated with increased blood Cr. SDMA and Cr were measured in 65 banked samples (serum and plasma) from 30 individual captive tigers. The samples were collected over a 38-y period and stored at -21°C. SDMA and Cr concentrations were determined using the commercially available SDMA test and enzymatic colorimetric methods, respectively. SDMA had a significant positive association with Cr (for every 1 unit increase of log SDMA, Cr increased by 82%, P = 0.0002). Age and subspecies influenced Cr but not SDMA concentrations. In one animal, blood SDMA increased above the ZIMS reported range. approximately 3.6 mo before Cr increased. SDMA is currently indicated for the diagnosis of CKD in domestic felids and seems also promising in nondomestic felids. Further prospective studies might improve the understanding of the performance of this biomarker.

FELINE CORONAVIRUS AND FELINE INFECTIOUS PERITONITIS IN NONDOMESTIC FELID SPECIES.

Feline coronavirus (FCoV) is reported worldwide and known to cause disease in domestic and nondomestic felid species. Although FCoV often results in mild to inapparent disease, a small subset of cats succumb to the fatal, systemic disease feline infectious peritonitis (FIP). An outbreak of FIP in Cheetahs (Acinonyx jubatus) in a zoological collection demonstrated the devastating effect of FCoV introduction into a naïve group of animals. In addition to cheetahs, FIP has been described in European wildcats (Felis silvestris), a tiger (Panthera tigris), a mountain lion (Puma concolor), and lion (Panthera leo). This paper reviews the reported cases of FIP in nondomestic felid species and highlights the surveys of FCoV in populations of nondomestic felids.

Anthropogenic Infection of Cats during the 2020 COVID-19 Pandemic.

COVID-19 is a severe acute respiratory syndrome (SARS) caused by a new coronavirus (CoV), SARS-CoV-2, which is closely related to SARS-CoV that jumped the animal–human species barrier and caused a disease outbreak in 2003. SARS-CoV-2 is a betacoronavirus that was first described in 2019, unrelated to the commonly occurring feline coronavirus (FCoV) that is an alphacoronavirus associated with feline infectious peritonitis (FIP). SARS-CoV-2 is highly contagious and has spread globally within a few months, resulting in the current pandemic. Felids have been shown to be susceptible to SARS-CoV-2 infection. Particularly in the Western world, many people live in very close contact with their pet cats, and natural infections of cats in COVID-19-positive households have been described in several countries. In this review, the European Advisory Board on Cat Diseases (ABCD), a scientifically independent board of experts in feline medicine from 11 European Countries, discusses the current status of SARS-CoV infections in cats. The review examines the host range of SARS-CoV-2 and human-to-animal transmissions, including infections in domestic and non-domestic felids, as well as mink-to-human/-cat transmission. It summarises current data on SARS-CoV-2 prevalence in domestic cats and the results of experimental infections of cats and provides expert opinions on the clinical relevance and prevention of SARS-CoV-2 infection in cats.

Taxonomic Distribution of Neoplasia Among Non-Domestic Felid Species Under Managed Care.

Simple SummaryNeoplasia in nondomestic felids is common, and frequently malignant. However, few studies include large sample sizes of non-Panthera felids. Jaguars are reported to potentially have genetic mutations that predispose them to cancer, but studied populations are limited to North American zoos. By including animals from USA, Mexico, Colombia, Peru, and Brazil, the present study was able to include animals with widely varying genetic backgrounds, diets, and management. This study found that jaguars, lions, tigers and leopards are at a much higher risk of developing cancer than small cats. It also documented that the most common site for neoplasm development is the reproductive tract, followed by the respiratory system and then blood and lymphatic systems. These data provide support for thorough investigation of suspicious lesions to enable early detection of cancer.As evidenced by numerous case reports from zoos, neoplasia in felids is common, but most reports are limited to Panthera species in North America or Europe. In order to obtain a wider epidemiologic understanding of neoplasia distribution, necropsy records at seven facilities (USA, Mexico, Colombia, Peru, and Brazil) were evaluated. In contrast to others, this study population (195 cases, 16 species), included many non-Panthera felids. Overall neoplasia prevalence was 28.2% (55/195). Panthera species had a higher prevalence of neoplasia than non-Panthera species (52.5%; vs. 13.0%). Lions (66.7%), jaguars (55.0%), and tigers (31.3%) had the highest species-specific prevalence of neoplasia. Neoplasms in Panthera species were more frequently malignant than in non-Panthera (86.1% vs. 55.6%). The systems most commonly affected were the reproductive, hematolymphoid, and respiratory. The range of management conditions and more varied genetic backgrounds support a robust taxonomic pattern and suggest that the reported propensity for neoplasia in jaguars may have a genetic basis at a taxonomic level higher than species, as lions and tigers also have high prevalence. Given the high prevalence of neoplasia and high likelihood of malignancy, routine medical exams in all nondomestic felids, but Panthera species in particular, should include thorough assessments of any clinical signs of neoplasia.

THE EFFECTS OF PROCEDURE DURATION AND ATIPAMEZOLE ADMINISTRATION ON HYPERKALEMIA IN TIGERS (PANTHERA TIGRIS) AND LIONS (PANTHERA LEO) ANESTHETIZED WITH α-2 AGONISTS.

A retrospective analysis of 40 extended (>2 hr) anesthetic events in eight lions (Panthera leo) and 32 tigers (Panthera tigris) was performed using a hierarchical linear growth curve model to assess the effects of anesthetic time, α-2 adrenoreceptor agonist dosages, administration of atipamezole, and biochemical parameters on rising plasma K+ concentrations. Hyperkalemia was first noted at a mean time of 187 min (range: 131-226 min), with time under anesthesia as a statistically significant predictor of K+ concentration (P < 0.0001). A significant two-way interaction between time and atipamezole administration (P = 0.0082) for rising K+ concentrations was demonstrated, indicating that administration of atipamezole can mitigate the rise in K+ concentrations. Administration of atipamezole beyond 150 min of anesthetic time was less effective in reducing K+ concentrations than if administered earlier. Electrocardiographic abnormalities were noted in eight animals, including three hyperkalemic individuals. Lions developed significantly greater plasma K+ concentrations than tigers (P = 0.0009) during anesthesia. No biochemical parameter was identified as a significant indicator of which individuals will develop hyperkalemia. Clinicians anesthetizing any large nondomestic felid should monitor electrolytes regularly during anesthetic events; consider early, partial- to full-dose reversal of α-2 agonists; and be prepared to correct potentially life-threatening electrocardiographic abnormalities resulting from hyperkalemia.

Oral Lesions in Captive Nondomestic Felids With a Focus on Odontogenic Lesions.

Odontogenic lesions are well described in domestic cats, but published literature describing these lesions in nondomestic felids is limited. This study reports oral lesions in 109 captive, non-domestic felids. Ten cases of odontogenic lesions were diagnosed, including 9 with fibromatous epulis of periodontal ligament origin (FEPLO) and one odontogenic cyst in a cougar. FEPLO was common in lions. FEPLO did not recur after surgical removal in any of the 3 cases for which follow-up information was available. Increased occurrences of oral papillomas in snow leopards and eosinophilic granulomas in tigers were identified, which is consistent with the reported literature. With the exception of oral papillomas in snow leopards and FEPLO in lions, the spectrum of oral lesions in nondomestic felids was similar to what is reported in domestic cats, with squamous cell carcinoma being the most common oral malignancy, and stomatitis/gingivitis/glossitis accounting for approximately one third of all cases. Rare diagnoses with one case each included hemangioma, fibrosarcoma, melanoma, cleft palate, and glossal amyloidosis.

SARS-COV-2 INFECTION AND LONGITUDINAL FECAL SCREENING IN MALAYAN TIGERS (PANTHERA TIGRIS JACKSONI), AMUR TIGERS (PANTHERA TIGRIS ALTAICA ), AND AFRICAN LIONS (PANTHERA LEO KRUGERI) AT THE BRONX ZOO, NEW YORK, USA.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) emerged as the cause of a global pandemic in 2019-2020. In March 2020, New York City became the epicenter in the United States for the pandemic. On 27 March 2020, a Malayan tiger (Panthera tigris jacksoni) at the Bronx Zoo in New York City developed a cough and wheezing with subsequent inappetence. Over the next week, an additional Malayan tiger and two Amur tigers (Panthera tigris altaica) in the same building and three lions (Panthera leo krugeri) in a separate building also became ill. The index case was anesthetized for diagnostic workup. Physical examination and bloodwork results were unremarkable. Thoracic radiography and ultrasonography revealed a bronchial pattern with peribronchial cuffing and mild lung consolidation with alveolar-interstitial syndrome, respectively. SARS-CoV-2 RNA was identified by real-time, reverse transcriptase PCR (rRT-PCR) on oropharyngeal and nasal swabs and tracheal wash fluid. Cytologic examination of tracheal wash fluid revealed necrosis, and viral RNA was detected in necrotic cells by in situ hybridization, confirming virus-associated tissue damage. SARS-CoV-2 was isolated from the tracheal wash fluid of the index case, as well as the feces from one Amur tiger and one lion. Fecal viral RNA shedding was confirmed in all seven clinical cases and an asymptomatic Amur tiger. Respiratory signs abated within 1-5 days for most animals, although they persisted intermittently for 16 days in the index case. Fecal RNA shedding persisted for as long as 35 days beyond cessation of respiratory signs. This case series describes the clinical presentation, diagnostic evaluation, and management of tigers and lions infected with SARS-CoV-2 and describes the duration of viral RNA fecal shedding in these cases. This report documents the first known natural transmission of SARS-CoV-2 from humans to nondomestic felids.