Quantifying visual acuity of Terrapene carolina triunguis utilizing optokinetic response.

OBJECTIVE: Quantify visual acuity of a semi-aquatic turtle species, Terrapene carolina triunguis (three-toed box turtles), utilizing optokinetic response/reflex/nystagmus. METHODS: Ten turtles were placed on a custom platform and an image of white and black gratings of varying sized widths was projected onto a white screen in front of the turtles. Optokinetic response (OKR) was observed through a web camera as well as physically by an observer. The grating sizes were decreased until OKR could not be elicited. The size of grating was recorded and was used to calculate visual acuity. RESULTS: The average visual acuity was 0.26 cycle per degree (cpd) with the highest recorded value being 0.43 cpd and lowest being 0.15 cpd. Neither sex nor weight were significantly associated with visual acuity (p = .24 and .98, respectively). CONCLUSIONS: Visual acuity of these semi-aquatic turtles was much lower than previously reported visual acuities of aquatic turtles. This could be due to differences in refractive indices between water and air, behavioral adaptations for the different species and/or method of obtaining visual acuity.

Veterinarians' perceptions of COVID-19 pandemic-related influences on veterinary telehealth and on pet owners' attitudes toward cats and dogs.

OBJECTIVE: To gather and evaluate veterinarians' perspectives about the impacts of the COVID-19 pandemic on the use of veterinary telehealth and on cat owners' versus dog owners' attitudes toward transmission of the SARS-CoV-2 virus from their pets. SAMPLE: 93 respondent veterinarians (47 in primary care practice and 46 in specialty practice). PROCEDURES: An online survey was conducted between June 15 and July 15, 2020, and included 21 questions concerning demographics, use of telehealth before and after the onset of the pandemic (before March 15, 2020, and between March 15 and June 15, 2020, respectively), changes in caseloads, and perception of clients' concerns about potential for transmission of the SARS-CoV-2 virus from pets. Reported zip codes informed the collection of census data. RESULTS: The level of poverty was significantly lower in zip code areas for respondents who reported telehealth services were (vs were not) offered before the pandemic. The percentage of respondents who reported their practice offered telehealth services increased from 12% (11/93) before the pandemic to 38% (35/93) between March 15 and June 15, 2020. Although most respondents reported owner-expressed concerns over SARS-CoV-2 virus transmission from their pets, most also reported increased caseloads, seeing newly adopted pets, and few discussions of surrender of pets for reasons related to the SARS-CoV-2 virus. CONCLUSIONS AND CLINICAL RELEVANCE: Findings indicated that caseloads increased and telehealth services expanded during the pandemic but that there was no evidence of differences in respondent-reported owner concern for SARS-CoV-2 virus transmission from cats versus dogs.

ANALYSIS OF HISTORICAL MEDICAL RECORDS OF CALIFORNIA CONDORS ( GYMNOGYPS CALIFORNIANUS) ADMITTED FOR LEAD EXPOSURE TO THE LOS ANGELES ZOO AND BOTANICAL GARDENS BETWEEN 1997 AND 2012: A CASE SERIES STUDY.

Lead toxicosis remains the primary cause of death in wild populations of California condors ( Gymnogyps californianus). Many condors require medical intervention with lead chelation therapy, among other conservation measures, to survive in the wild. An analysis of historical medical records of California condors admitted for lead exposure to the Los Angeles Zoo and Botanical Gardens (LA Zoo) between 1997 and 2012 was performed to investigate clinical presentation, radiographic findings, and treatment along with the potential impact of these factors on recovery and successful release back into the wild. Of 100 individual condors presented to the LA Zoo for suspected lead toxicosis during this period, 84 condors had records for initial laboratory blood lead levels. For these 84 condors (40 [47.6%] females and 44 [52.4%] males), 277 initial laboratory blood lead levels in total were recorded because of repeated admissions. Thirty-two (38%) condors were admitted once to the zoo and 62% were admitted two or more times. Clinical signs were not observed in 87.5% of the condors admitted with median blood lead concentrations of 26 µg/dl. Of the radiographs taken on initial presentation, 65% did not show evidence of gastrointestinal metallic foreign bodies. Various treatments protocols with edetatum calcium disodium, dimercaptosuccinic acid, and lactated Ringer's solution were documented in the medical records. Of the 277 admissions, 154 admissions had a recorded outcome posttreatment of which 140 (91%) admissions were released back to the wild. This study contributes to a better understanding of how intervention and therapeutic approaches have been essential for the recovery, release, and sustainability of these birds as a wild population. Consistency in data collection of California condors admitted for diagnosis and treatment of lead toxicosis is needed to better assess the impacts of medical interventions.

Glucocorticoid measurement in plasma, urates, and feathers from California condors (Gymnogyps californianus) in response to a human-induced stressor.

Vertebrates respond to stressful stimuli with the secretion of glucocorticoid (GC) hormones, such as corticosterone (CORT), and measurements of these hormones in wild species can provide insight into physiological responses to environmental and human-induced stressors. California condors (Gymnogyps californianus) are a critically endangered and intensively managed avian species for which information on GC response to stress is lacking. Here we evaluated a commercially available I125 double antibody radioimmunoassay (RIA) and an enzyme-linked immunosorbent assay (ELISA) kit for measurement of CORT and GC metabolites (GCM) in California condor plasma, urate, and feather samples. The precision and accuracy of the RIA assay outperformed the ELISA for CORT and GCM measurements, and CORT and GCM values were not comparable between the two assays for any sample type. RIA measurements of total CORT in condor plasma collected from 41 condors within 15 minutes of a handling stressor were highly variable (median = 70 ng/mL, range = 1-189 ng/mL) and significantly different between wild and captive condors (p = 0.02, two-tailed t-test, n = 10 wild and 11 captive). Urate GCM levels (median = 620 ng/g dry wt., range = 0.74-7200 ng/g dry wt., n = 216) significantly increased within 2 hr of the acute handling stressor (p = 0.032, n = 11 condors, one-tailed paired t-test), while feather section CORT concentrations (median = 18 pg/mm, range = 6.3-68 ng/g, n = 37) also varied widely within and between feathers. Comparison of multiple regression linear models shows condor age as a significant predictors of plasma CORT levels, while age, sex, and plasma CORT levels predicted GCM levels in urates collected within 30 min of the start of handling. Our findings highlight the need for validation when selecting an immunoassay for use with a new species, and suggest that non-invasively collected urates and feathers hold promise for assessing condor responses to acute or chronic environmental and human-induced stressors.

Survey of U.S.-based zoo veterinarians' attitudes on population management euthanasia.

Population management euthanasia, or culling, is a recognized tool for managing animal populations in human care. Previous research in zoos has shown that animal care staff attitudes about culling vary based on gender, job type, awareness of culling, the taxon in question for culling, and situational factors, but the attitudes of zoo veterinarians have not been studied previously, despite the fact that they are often tasked with carrying out euthanasia. We surveyed a sample of currently employed, zoo-based veterinarians in the United States on their knowledge and attitudes about population management euthanasia. Veterinarians demonstrated a high knowledge and awareness of population management euthanasia and were as supportive, if not more supportive, of it than previously surveyed groups. Similar to previous studies, attitudes about culling varied with the type of animal being considered for euthanasia. Female veterinarians and those veterinarians not aware of population management euthanasia events at their facilities were less supportive of the practice, again in agreement with previous studies of other zoo professionals. Veterinarians tended to be either more population-focused or individual-focused in their thinking about culling for population management compared to other zoo personnel, who often rated themselves as considering the needs of populations and individuals more equally. Our results suggest that veterinarians are important stakeholders in discussions about population management euthanasia in zoos and are likely to be supportive when information on rationale is presented.

PROSPECTIVE POPULATION MANAGEMENT FOR HEPATITIS B IN THE CHIMPANZEE (PAN TROGLODYTES) SSP® POPULATION.

Hepatitis B virus causes horizontally transmitted infectious hepatopathy of primates and may progress to hepatocellular carcinoma. Historically, a small number of chimpanzees ( Pan troglodytes ) living in accredited North American zoos have been confirmed with positive hepatitis B serology consistent with exposure. However, the overall status for this population and the interpretation of these individual test results have not been established previously. The current U.S. zoo-housed population (n = 259) was assessed serologically for hepatitis B by surface protein antigen (HbsAg) and surface antibodies (anti-Hbs). Signalment, origin, current health status, history of liver disease, and hepatitis B vaccination history were obtained for each animal. Serologic status was measured directly in 86.5% (n = 224) of these individuals, with 2.2% (n = 5) of the study population determined to be chronically infected by positive HbsAg and negative anti-Hbs status. Additionally, 11.6% (n = 26) of the directly measured population tested were HbsAg negative and anti-Hbs positive, which was indicative of viral exposure. No animals were determined to be acutely infected as HbsAg and anti-Hbs positive. Although these results demonstrated a relatively low prevalence of hepatitis B infection among these chimpanzees, the varied serologic results between institutions underscored the importance of routine serologic testing, especially at times of proposed transfers, and consideration of species vaccination protocols.

Integrating Genomic Data Sets for Knowledge Discovery: An Informed Approach to Management of Captive Endangered Species.

Many endangered captive populations exhibit reduced genetic diversity resulting in health issues that impact reproductive fitness and quality of life. Numerous cost effective genomic sequencing and genotyping technologies provide unparalleled opportunity for incorporating genomics knowledge in management of endangered species. Genomic data, such as sequence data, transcriptome data, and genotyping data, provide critical information about a captive population that, when leveraged correctly, can be utilized to maximize population genetic variation while simultaneously reducing unintended introduction or propagation of undesirable phenotypes. Current approaches aimed at managing endangered captive populations utilize species survival plans (SSPs) that rely upon mean kinship estimates to maximize genetic diversity while simultaneously avoiding artificial selection in the breeding program. However, as genomic resources increase for each endangered species, the potential knowledge available for management also increases. Unlike model organisms in which considerable scientific resources are used to experimentally validate genotype-phenotype relationships, endangered species typically lack the necessary sample sizes and economic resources required for such studies. Even so, in the absence of experimentally verified genetic discoveries, genomics data still provides value. In fact, bioinformatics and comparative genomics approaches offer mechanisms for translating these raw genomics data sets into integrated knowledge that enable an informed approach to endangered species management.

Seroepidemiologic Survey of Potential Pathogens in Obligate and Facultative Scavenging Avian Species in California.

Throughout the world, populations of scavenger birds are declining rapidly with some populations already on the brink of extinction. Much of the current research into the factors contributing to these declines has focused on exposure to drug residues, lead, and other toxins. Despite increased monitoring of these declining populations, little is known about infectious diseases affecting scavenger bird species. To assess potential infectious disease risks to both obligate and facultative scavenger bird species, we performed a serosurvey for eleven potential pathogens in three species of scavenging birds in California: the California condor (Gymnogyps californianus), turkey vulture (Cathartes aura) and golden eagle (Aquila chrysaetos). California condors were seropositive for avian adenovirus, infectious bronchitis virus, Mycoplasma gallisepticum, avian paramyxovirus-2, West Nile virus (WNV) and Toxoplasma gondii. Golden eagles were seropositive for avian adenovirus, Chlamydophila psittaci and Toxoplasma gondii, and turkey vultures were seropositive for avian adenovirus, Chlamydophila psittaci, avian paramyxovirus-1, Toxoplasma gondii and WNV. Risk factor analyses indicated that rearing site and original release location were significantly associated with a positive serologic titer to WNV among free-flying condors. This study provides preliminary baseline data on infectious disease exposure in these populations for aiding in early disease detection and provides potentially critical information for conservation of the endangered California condor as it continues to expand its range and encounter new infectious disease threats.

Reproductive activity in the peninsular pronghorn determined from excreted gonadal steroid metabolites.

Fecal hormone monitoring was employed to better define annual patterns of reproductive steroid metabolites from a breeding pair of peninsular pronghorn (Antilocapra americana peninsularis) maintained at the Los Angeles Zoo. Notably in the female, increased excretion of estrogen metabolites occurred during the breeding season (Jun-Aug), and a biphasic pattern in progestagen activity was measured during gestation. Of additional interest, a preterm increase in estrogen that continued for an additional 64 days post partum. Male androgen activity correlated with the female estrogen patterns, with a single successful copulation occurring during the breeding season; interestingly however, the male exhibited no reproductive behaviors during the female's preterm/post partum estrogen increase. These data are the first reproductive steroid profiles for the peninsular pronghorn and provide valuable insight that will aid efforts that link the species' reproductive physiology with conservation management.

Linking cases of illegal shootings of the endangered California condor using stable lead isotope analysis.

Lead poisoning is preventing the recovery of the critically endangered California condor (Gymnogyps californianus) and lead isotope analyses have demonstrated that ingestion of spent lead ammunition is the principal source of lead poisoning in condors. Over an 8 month period in 2009, three lead-poisoned condors were independently presented with birdshot embedded in their tissues, evidencing they had been shot. No information connecting these illegal shooting events existed and the timing of the shooting(s) was unknown. Using lead concentration and stable lead isotope analyses of feathers, blood, and recovered birdshot, we observed that: i) lead isotope ratios of embedded shot from all three birds were measurably indistinguishable from each other, suggesting a common source; ii) lead exposure histories re-constructed from feather analysis suggested that the shooting(s) occurred within the same timeframe; and iii) two of the three condors were lead poisoned from a lead source isotopically indistinguishable from the embedded birdshot, implicating ingestion of this type of birdshot as the source of poisoning. One of the condors was subsequently lead poisoned the following year from ingestion of a lead buckshot (blood lead 556 µg/dL), illustrating that ingested shot possess a substantially greater lead poisoning risk compared to embedded shot retained in tissue (blood lead ~20 µg/dL). To our knowledge, this is the first study to use lead isotopes as a tool to retrospectively link wildlife shooting events.

Development of a PCR assay to detect papillomavirus infection in the snow leopard.

BACKGROUND: Papillomaviruses (PVs) are a group of small, non-encapsulated, species-specific DNA viruses that have been detected in a variety of mammalian and avian species including humans, canines and felines. PVs cause lesions in the skin and mucous membranes of the host and after persistent infection, a subset of PVs can cause tumors such as cervical malignancies and head and neck squamous cell carcinoma in humans. PVs from several species have been isolated and their genomes have been sequenced, thereby increasing our understanding of the mechanism of viral oncogenesis and allowing for the development of molecular assays for the detection of PV infection. In humans, molecular testing for PV DNA is used to identify patients with persistent infections at risk for developing cervical cancer. In felids, PVs have been isolated and sequenced from oral papillomatous lesions of several wild species including bobcats, Asian lions and snow leopards. Since a number of wild felids are endangered, PV associated disease is a concern and there is a need for molecular tools that can be used to further study papillomavirus in these species. RESULTS: We used the sequence of the snow leopard papillomavirus UuPV1 to develop a PCR strategy to amplify viral DNA from samples obtained from captive animals. We designed primer pairs that flank the E6 and E7 viral oncogenes and amplify two DNA fragments encompassing these genes. We detected viral DNA for E6 and E7 in genomic DNA isolated from saliva, but not in paired blood samples from snow leopards. We verified the identity of these PCR products by restriction digest and DNA sequencing. The sequences of the PCR products were 100% identical to the published UuPV1 genome sequence. CONCLUSIONS: We developed a PCR assay to detect papillomavirus in snow leopards and amplified viral DNA encompassing the E6 and E7 oncogenes specifically in the saliva of animals. This assay could be utilized for the molecular investigation of papillomavirus in snow leopards using saliva, thereby allowing the detection of the virus in the anatomical site where oral papillomatous lesions develop during later stages of infection and disease development.