Search

Pharmacokinetics studies have investigated meloxicam, a non-steroidal anti-inflammatory drug, dosing strategies in a wide variety of non-domestic animals; however, there is no prior study examining well-founded dosing for pinnipeds. To develop dosing protocols, pharmacokinetic information is needed, with an examination of differences between pinniped species. Apparently, healthy California sea lions (Zalophus californianus: CSL; n = 13) and Pacific harbor seals (Phoca vitulina richardii: PHS; n = 17) that had completed rehabilitation were enrolled into a population-based pharmacokinetic study. Each animal was administered a single oral dose of meloxicam at 0.1 mg/kg, and two blood samples were collected from each animal at varying intervals during a 96-h study period. Plasma concentrations of meloxicam were determined by high-pressure liquid chromatography. Data were analyzed with nonlinear mixed effects modeling (Phoenix® NLME™, Certara, St. Louis, MO 63105, USA). The results indicated that in PHS, peak plasma concentration (C max ) was 0.33 μg/mL with an elimination half-life (K e t½) of 31.53 h. In CSL, C max was 0.17 μg/mL with K e t½ of 32.71 h. All animals enrolled completed the study without outward adverse clinical signs. The elimination half-life was longer than previously recommended dosing intervals for pinnipeds; however, we cannot speculate in the optimum clinical dose from these results., (© 2024 The Author(s). Journal of Veterinary Pharmacology and Therapeutics published by John Wiley & Sons Ltd.)

Since 1998, California sea lion ( Zalophus californianus ) stranding events associated with domoic acid toxicosis (DAT) have consistently increased. Outside of direct measurement of domoic acid in bodily fluids at the time of stranding, there are no practical nonlethal clinical tests for the diagnosis of DAT that can be utilized in a rehabilitation facility. Proteomics analysis was conducted to discover candidate protein markers of DAT using cerebrospinal fluid from stranded California sea lions with acute DAT ( n = 8), chronic DAT ( n = 19), or without DAT ( n = 13). A total of 2005 protein families were identified experiment-wide. A total of 83 proteins were significantly different in abundance across the three groups (adj. p < 0.05). MDH1, PLD3, ADAM22, YWHAG, VGF, and CLSTN1 could discriminate California sea lions with or without DAT (AuROC > 0.75). IGKV2D-28, PTRPF, KNG1, F2, and SNCB were able to discriminate acute DAT from chronic DAT (AuROC > 0.75). Proteins involved in alpha synuclein deposition were over-represented as classifiers of DAT, and many of these proteins have been implicated in a variety of neurodegenerative diseases. These proteins should be considered potential markers for DAT in California sea lions and should be prioritized for future validation studies as biomarkers.

The consumption of primates is integral to the traditional subsistence strategies of many Indigenous communities throughout Amazonia. Understanding the overall health of primates harvested for food in the region is critical to Indigenous food security and thus, these communities are highly invested in long-term primate population health. Here, we describe the establishment of a surveillance comanagement program among the Waiwai, an Indigenous community in the Konashen Amerindian Protected Area (KAPA). To assess primate health in the KAPA, hunters performed field necropsies on primates harvested for food and tissues collected from these individuals were analyzed using histopathology. From 2015 to 2019, hunters conducted 127 necropsies across seven species of primates. Of this sample, 82 primates (between 2015 and 2017) were submitted for histopathological screening. Our histopathology data revealed that KAPA primates had little evidence of underlying disease. Of the tissue abnormalities observed, the majority were either due to diet (e.g., hepatocellular pigment), degenerative changes resulting from aging (e.g., interstitial nephritis, myocyte lipofusion), or nonspecific responses to antigenic stimulation (renal and splenic lymphoid hyperplasia). In our sample, 7.32% of individuals had abnormalities that were consistent with a viral etiology, including myocarditis and hepatitis. Internal parasites were observed in 53.66% of individuals and is consistent with what would be expected from a free-ranging primate population. This study represents the importance of baseline data for long-term monitoring of primate populations hunted for food. More broadly, this research begins to close a critical gap in zoonotic disease risk related to primate harvesting in Amazonia, while also demonstrating the benefits of partnering with Indigenous hunters and leveraging hunting practices in disease surveillance and primate population health assessment., (© 2024 The Authors. American Journal of Primatology published by Wiley Periodicals LLC.)

Air leak syndrome (ALS) is described in human medicine as a constellation of clinical disorders including pneumomediastinum, pneumopericardium, pulmonary interstitial emphysema, pneumothorax, pneumoperitoneum, pneumoretroperitoneum and subcutaneous emphysema. The pathogenesis of ALS depends on the anatomy of the mediastinum and its associations with thoracic, abdominal and cervical connective tissues, as well as a physical phenomenon referred to as the Macklin effect. Various animal species develop diverse combinations of these lesions, although ALS has not been recognized in animals. However, this term aids pathologists in addressing this disease compilation. The aim of this retrospective study is to illustrate examples of ALS in animals by arbitrarily selecting 13 cases in dogs, cats, pinnipeds, sea otters and harbour porpoises. ALS can be classified into three groups based on aetiology: iatrogenic, secondary or spontaneous. Iatrogenic ALS was diagnosed in two cats with tracheal laceration following endotracheal intubation. Secondary ALS was identified in two dogs, one with acute respiratory distress syndrome and the other due to grass awn migration. Secondary ALS in pinnipeds was diagnosed following severe pulmonary parasitism, uraemic pneumonia and oesophageal perforation. The other marine mammals developed ALS following trauma. Spontaneous ALS was also diagnosed in one cat and one dog without any apparent predisposing causes., Competing Interests: Declaration of competing interests The authors declared no conflicts of interest in relation to the research, authorship or publication of this article., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Fish serve as indicators of exposure to contaminants of emerging concern (CECs)-chemicals such as pharmaceuticals, hormones, and personal care products-which are often designed to impact vertebrates. To investigate fish health and CECs in situ, we evaluated the health of wild fish exposed to CECs in waterbodies across northeastern Minnesota with varying anthropogenic pressures and CEC exposures: waterbodies with no human development along their shorelines, those with development, and those directly receiving treated wastewater effluent. Then, we compared three approaches to evaluate the health of fish exposed to CECs in their natural environment: a refined fish health assessment index, a histopathological index, and high-throughput (ToxCast) in vitro assays. Lastly, we mapped adverse outcome pathways (AOPs) associated with identified ToxCast assays to determine potential impacts across levels of biological organization within the aquatic system. These approaches were applied to subsistence fish collected from the Grand Portage Indian Reservation and 1854 Ceded Territory in 2017 and 2019. Overall, 24 CECs were detected in fish tissues, with all but one of the sites having at least one detection. The combined implementation of these tools revealed that subsistence fish exposed to CECs had histological and macroscopic tissue and organ abnormalities, although a direct causal link could not be established. The health of fish in undeveloped sites was as poor, or sometimes poorer, than fish in developed and wastewater effluent-impacted sites based on gross and histologic tissue lesions. Adverse outcome pathways revealed potential hazardous pathways of individual CECs to fish. A better understanding of how the health of wild fish harvested for consumption is affected by CECs may help prioritize risk management research efforts and can ultimately be used to guide fishery management and public health decisions. Integr Environ Assess Manag 2024;20:846-863. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC)., (© 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).)

Beginning in December 2018, increased numbers of gray whale (Eschrichtius robustus) strandings were reported along the west coast of Mexico, the United States, and Canada, prompting declaration of a gray whale Unusual Mortality Event (UME) by the United States National Marine Fisheries Service. Although strandings declined in 2020 and 2021 from a peak in 2019, the UME is still ongoing as of fall 2023. Between 17 December 2018 and 31 December 2021, 503 animals stranded along the west coast of North America, with 226 strandings in Mexico, 71 in California, 12 in Oregon, 56 in Washington, 21 in British Columbia, and 117 in Alaska. These included 187 males, 167 females, and 149 whales of undetermined sex; and 193 adults, 194 subadults, 40 calves, 1 fetus, and 75 whales of undetermined age class. We report on 61 of the 503 carcasses (12%) that had external and internal gross necropsy and/or histopathology data: of these 61 whales, findings that contributed to death were identified in 33 (54%) whales. Sixteen of the 61 (26%) were severely emaciated. Gross lesions of blunt force trauma consistent with vessel strike were identified in 11 of the 61 animals (18%), only two of which were emaciated. Two whales (3%) were entangled at time of death, and one died from entrapment. Signs of killer whale (Orcinus orca) interaction were documented in 19 of the 61 animals; five were deemed from recent interactions and three (5%) likely contributed to mortality. A specific cause of death could not be identified in 28 of 61 whales (46%). Additionally, logistical challenges and the advanced state of decomposition of most examined carcasses precluded detection of potential infectious or toxic causes of morbidity or mortality. Up to 2016, the eastern North Pacific population of gray whale population had generally been increasing since the cessation of historic whaling and a prior UME in 1999-2000. However, recent abundance and calf production estimates have declined, a trend that overlaps the current UME. The relative contributions of carrying capacity, environmental change, prey shifts, and infectious, toxic, and other processes to the increased gray whale mortalities have not yet been resolved. Nevertheless, the marked temporal increase in strandings, including findings of malnutrition in some of the whales, along with low calf production, likely represent consequences of complex and dynamic ecological interactions in the ocean impacting the population., Competing Interests: The authors have no competing interests., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)

Phocine distemper virus (PDV) is a significant cause of mortality for phocid seals; however, the susceptibility of otariids to this virus is poorly understood. The authors used a lymph-node explant culture system from California sea lions ( Zalophus californianus , CSL) to investigate: (1) the role of signaling lymphocyte activation molecule (SLAM) and nectin-4 in PDV infection and their cellular expression patterns, (2) if PDV induces transcriptional regulation of cell-entry receptors, and (3) the involvement of apoptosis in PDV infection. PDV replicated in the lymph-node explants with peak replication 3 days post-infection (dpi), but the replication was not sustained 4 to 5 dpi. The PDV+ cells co-localized SLAM and nectin-4. These cells expressed IBA1, indicating a histiocytic lineage. Comparison of receptor expression between infected and mock-infected lymph nodes suggested transcriptional downregulation of both receptors during the initial stage of infection and upregulation during the late stage of infection, but the values lack of statistical significance. Cleaved caspase-3+ cells were slightly increased in the infected lymph nodes compared with the mock-infected lymph node from 1 to 4 dpi, but without statistical significance, and a few apoptotic cells co-expressed PDV. The results suggest that lymph-node explants might be an important model to study PDV pathogenesis. CSLs have the potential to be infected with PDV, as they express both cell-entry receptors in histiocytes. The lack of statistical significance in the PDV replication, transcriptional regulation of viral receptors, and changes in apoptosis suggest that although CSL might be infected by PDV, they might be less susceptible than phocid species., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

A southern sea otter (Enhydra lutris nereis) stranded dead in central California, USA, with a distended pericardial sac containing thousands of free-floating proteinaceous masses. Serology, fungal culture, PCR, and sequencing confirmed the etiology of this novel lesion as Coccidioides immitis. Range expansion of this zoonotic pathogen is predicted with climate change., (© Wildlife Disease Association 2024.)

Microbial community assembly remains largely unexplored in marine mammals, despite its potential importance for conservation and management. Here, neonatal microbiota assembly was studied in harbour seals (Phoca vitulina richardii) at a rehabilitation facility soon after maternal separation, through weaning, to the time of release back to their native environment. We found that the gingival and rectal communities of rehabilitated harbour seals were distinct from the microbiotas of formula and pool water, and became increasingly diverse and dissimilar over time, ultimately resembling the gingival and rectal communities of local wild harbour seals. Harbour seal microbiota assembly was compared to that of human infants, revealing the rapid emergence of host specificity and evidence of phylosymbiosis even though these harbour seals had been raised by humans. Early life prophylactic antibiotics were associated with changes in the composition of the harbour seal gingival and rectal communities and surprisingly, with transient increases in alpha diversity, perhaps because of microbiota sharing during close cohabitation with other harbour seals. Antibiotic-associated effects dissipated over time. These results suggest that while early life maternal contact may provide seeding for microbial assembly, co-housing of conspecifics during rehabilitation may help neonatal mammals achieve a healthy host-specific microbiota with features of resilience., (© 2023 The Authors. Environmental Microbiology published by Applied Microbiology International and John Wiley & Sons Ltd. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Introduction: Domoic acid (DA) is a glutaminergic excitatory neurotoxin that causes the morbidity and mortality of California sea lions (Zalophus californianus; CSL) and other marine mammals due to a suite of effects mostly on the nervous and cardiac systems. Between 1998 and 2019, 11,737 live-stranded CSL were admitted to The Marine Mammal Center (TMMC; Sausalito, CA, USA), over 2,000 of which were intoxicated by DA. A plethora of clinical research has been performed over the past 20 years to characterize the range of toxic effects of DA exposure on CSLs, generating the largest dataset on the effects of natural exposure to this toxin in wildlife., Materials and Methods: In this study, we review published methods for diagnosing DA intoxication, clinical presentation, and treatment of DA-intoxicated CSL and present a practical, reproducible scoring system called the neuroscore (NS) to help assess whether a DA-affected CSL is fit for release to the wild following rehabilitation. Logistic regression models were used to assess the relationships between outcome (released vs. euthanized or died) and multiple variables to predict the outcome for a subset of 92 stranded CSLs., Results: The largest proportion of DA-intoxicated CSLs was adult females (58.6%). The proportions of acute and chronic cases were 63.5 and 36.5% respectively, with 44% of affected CSL released and 56% either dying naturally or euthanized. The average time in rehabilitation was 15.9 days (range 0-169) for all outcomes. The best-performing model (85% accuracy; area under the curve = 0.90) assessing the relationship between outcome and predictor variables consisted of four variables: final NS, change in NS over time, whether the animal began eating in rehabilitation, and the state of nutrition on admission., Discussion: Our results provide longitudinal information on the symptomatology of CSL intoxicated by domoic acid and suggest that a behavioral scoring system is a useful tool to assess the fitness for the release of DA-intoxicated CSL., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 McClain, Field, Norris, Borremans, Duignan, Johnson, Whoriskey, Thompson-Barbosa and Gulland.)

General anesthesia is often required in elasmobranch species for medical procedures. A variety of anesthetic drugs have been administered to elasmobranchs with wide variability in efficacy and safety. A retrospective review of 47 anesthetic procedures using IV propofol in eight different elasmobranch species at the Georgia Aquarium from 2010 to 2022 was performed. Cases involving seven sand tiger sharks ( Carcharias taurus ), four largetooth sawfish ( Pristis perotteti ), one longcomb sawfish ( Pristis zijsron ), four blacktip reef sharks ( Carcharhinus melanopterus ), three silvertip sharks ( Carcharhinus albimarginatus), one sandbar shark ( Carcharhinus plumbeus ), five cownose rays ( Rhinoptera bonasus ), and one blotched fantail stingray ( Taeniura meyeni ) were evaluated. Induction dose of IV propofol (median: 2.5; 25-75%: 2.3-3.0; range: 1.7-4.0 mg/kg), time to desired effect (median: 4.0; 25-75%: 2.0-5.0; range: 0.5-15.0 min) and anesthetic duration (median: 76.0; 25-75%: 61.5-119.0; range: 27-216 min) were reported in all species. In six procedures (12.7%), maintenance of desired anesthetic plane required a supplemental dose of propofol IV (1 mg/kg) or addition of tricaine methanesulfonate (70 mg/L) as an immersion bath. The most common side effects were apnea and prolonged recovery. The IV propofol was efficacious and provided a procedural plane of anesthesia for a clinically relevant period of time in the majority of elasmobranch species, but observation for and management of complications is warranted.

Each year in the United States, thousands of sick, injured, or displaced wild animals are presented to individuals or organizations who have either a federal or state permit that allows them to care for these animals with the goal of releasing them back to the wild. The purpose of this review is to demonstrate the complexity of considerations rehabilitators and veterinarians face while trying to optimize the welfare of wild animals in need of care and rehabilitation. The process of rehabilitation is inherently stressful for wildlife. Maintaining an animal's welfare during the rehabilitation process-from initial contact and tria+ge to the animal's euthanasia, release, or captive placement-requires deliberate, timely and humane decision making. The welfare of wild animals can be improved by preventing human-related causes of admission, providing resources and support for wildlife rehabilitation (almost all rehabilitation in the United States is privately funded and access to veterinary care is often limited); further developing evidence-based wildlife rehabilitation methods and welfare measures, attracting more veterinary professionals to the field, harmonizing regulatory oversight with standards of care, training, and accountability, and increasing public education.

Domoic acid (DA) is a naturally occurring marine neurotoxin produced by Pseudo-nitzschia diatoms. Adult California sea lions (Zalophus californianus) can experience multiple post-exposure syndromes, including acute toxicosis and chronic epilepsy. Additionally, a delayed-onset epileptic syndrome is proposed for California sea lions (CSL) exposed in utero. This brief report explores a case of a CSL developing adult-onset epilepsy with progressive hippocampal neuropathology. Initial brain magnetic resonance imaging (MRI) and hippocampal volumetric analyses relative to brain size were normal. Approximately 7 years later, MRI studies to evaluate a newly developed epileptic syndrome demonstrated unilateral hippocampal atrophy. While other causes of unilateral hippocampal atrophy cannot be completely excluded, this case may represent in vivo evidence of adult-onset epileptiform DA toxicosis in a CSL. By estimating in utero DA exposure time period, and extrapolating from studies conducted on laboratory species, this case provides circumstantial evidence for a neurodevelopmental explanation correlating in utero exposure to adult-onset disease. Evidence of delayed disease development secondary to gestational exposure to naturally occurring DA has broad implications for marine mammal medicine and public health., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier B.V.)

This study was designed to identify abnormalities in the electroencephalograms (EEGs) recorded from stranded California sea lions ( Zalophus californianus ) with suspected domoic acid (DA) toxicosis . Recordings from animals presenting for non-neurological issues were also obtained to better understand the normal EEG (background activity and transient events) in this species, as, to date, studies have focused on examining natural sleep in pinnipeds. Most animals were sedated for electrode placement and EEG acquisition with some receiving antiepileptic medications or isoflurane during the procedure. A total of 103 recordings were read and scored from 0 (normal) to 3 (severely abnormal). Epileptiform discharges, consisting of spikes, sharp waves, slow waves, and/or spike waves, were present in all EEGs with scores of 1, 2, or 3. The distribution of these events over the scalp varied. While often generalized, others were lateralized over one hemisphere, bifrontal, bioccipital, and/or bitemporal, while some discharges were multifocal. Findings were different between sea lions and occasionally changed within the EEG on a given sea lion. No clinical seizures were observed during the recording but a few sea lions had findings consistent with electroencephalographic seizures. When available, supporting diagnostic results obtained from magnetic resonance imaging (MRI) and/or necropsy/histopathology were described, as well as the status of those sea lions that recovered and were released with satellite tags., Competing Interests: SD is employed by Imaging Solutions, PLLC. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Williams, Haulena, Dennison, Waugh, Goldstein, Nutter, Bonn, Hoard, Laxer, Buckmaster, Gulland and Tharp.)

From 2011-2018, we conducted surveillance in marine mammals along the California coast for influenza A virus (IAV), frequently detecting anti-influenza antibodies and intermittently detecting IAV. In spring 2019, this pattern changed. Despite no change in surveillance intensity, we detected IAV RNA in 10 samples in March and April, mostly in nasal and rectal swabs from northern elephant seals (Mirounga angustirostris). Although virus isolation was unsuccessful, IAV sequenced from one northern elephant seal nasal swab showed close genetic identity with pandemic H1N1 IAV subclade 6B.1A.1 that was concurrently circulating in humans in the 2018/19 influenza season. This represents the first report of human A(H1N1)pdm09 IAV in northern elephant seals since 2010, suggesting IAV continues to spill over from humans to pinnipeds., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Plancarte et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Recently, a novel gammaherpesvirus, miroungine gammaherpesvirus 3 (MirGHV3), was described in two juvenile elephant seals (Mirounga angustirostris) with diffuse large B-cell lymphoma. We developed and validated a quantitative (q)PCR for rapid detection of MirGHV3 and investigated its potential association with lymphoma. We developed a duplex probe-hybridization qPCR with MirGHV3 DNA polymerase (pol) as the target gene. Each primer-probe combination was cross-validated against the others. Interference was not seen when they were run in the same well as a duplex assay. Twenty-three samples from seven northern elephant seals were tested using the duplex assay. Viral DNA was detected by the assay in 9 of 9 (100%) tissues affected by lymphoma and in 6 of 14 (43%) samples from tissues unaffected by lymphoma. There was a strong correlation between viral copies detected with each of the assays (P=0.0002). Viral load was significantly higher in tissues affected by lymphoma than in those unaffected (P<0.0001). Excluding the virus-negative samples, viral load was still significantly higher in tissues affected by lymphoma than in those unaffected (P=0.0004). This is consistent with a potential role of MirGHV3 in oncogenesis in northern elephant seals, although more studies are needed to determine this definitively. The qPCR developed has utility for further investigations of MirGHV3., (© Wildlife Disease Association 2023.)

Little is known about the biology of pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales as these animals are difficult to observe in the wild. However, both species strand frequently along the South African, Australian and New Zealand coastlines, providing samples for these otherwise inaccessible species. The use of DNA samples from tissue and DNA extracted from historical material, such as teeth and bone, allowed a first analysis of the population structure of both species in the Southern Hemisphere. A 279 base pair consensus region of the mitochondrial cytochrome b gene was sequenced for 96 K. breviceps (53 tissue and 43 teeth or bone samples) and 29 K. sima (3 tissue and 26 teeth or bone samples), and 26 and 12 unique haplotypes were identified, respectively. K. breviceps showed a higher nucleotide diversity of 0.82% compared to 0.40% in K. sima. Significant genetic differentiation was detected in the Southern Hemisphere between K. breviceps from South Africa and New Zealand (Ф ST = 0.042, p < 0.05). Mitochondrial control region sequences (505 bp) were available for 44 individuals (41 K. breviceps and 3 K. sima) for comparative purposes. A comprehensive global phylogenetic analysis (maternal lineage) of our sequences together with all available Kogia mtDNA sequences largely supported previously published phylogenetic findings, but highlighted some changed inferences about oceanic divergences within both species. The higher nucleotide diversity and low population differentiation observed in K. breviceps may result from its broad foraging ecology and wide distribution, which may indicate a more opportunistic feeding behaviour and tolerance towards a larger range of water temperatures than K. sima., (Copyright © 2023. Published by Elsevier Ltd.)

Harbor seals ( Phoca vitulina ) are a common species admitted to marine mammal rehabilitation facilities. As important indicators of marine ecosystem health, monitoring trends of disease in harbor seal populations is critical. However, few studies have evaluated neurologic disease in this species. The general objective of this study was to retrospectively review and delineate neurologic disease in free-ranging Atlantic harbor seals ( P. vitulina concolor ) that stranded along the New England (United States) coast and entered a rehabilitation facility between 2006 and 2019. Any Atlantic harbor seal that stranded live along the New England coast during the study period and was diagnosed with neurologic disease on either antemortem or postmortem evaluation was included; medical records and pathologic reports were reviewed. From 211 records, 24 animals met the inclusion criteria. Prevalence of neurologic disease was 11% in the study population and six major categories of neurologic disease were identified including: inflammatory (54%), idiopathic (33%), trauma (4%), congenital (4%), and degenerative (4%). Of the seals diagnosed with neurologic disease, 13 (54%) seals died during rehabilitation, 10 (42%) seals were euthanized, and 1 (4%) seal survived to release. Unique cases seen included a seal with Dandy-Walker-like malformation and another seal with histopathologic findings compatible with neuroaxonal dystrophy, a degenerative process that has not been previously reported in marine mammals. This study contributes to the overall knowledge of the health of free-ranging Atlantic harbor seals and may aid clinicians in characterizing neurologic conditions that may be present in seals undergoing rehabilitation.

Tattoo skin disease (TSD) is a poxviral dermatopathy diagnosed in cetaceans. We review the literature on TSD aetiology, clinical characteristics, pathology and epidemiology and evaluate immune responses against the virus. In addition, necropsy reports for fifty-five harbour porpoises ( Phocoena phocoena ), twenty-two Delphinidae and four Kogiidae stranded in northern California in 2018-2021 were checked for diagnostic tattoo lesions. TSD occurs in the Mediterranean, North and Barents Seas, as well as in the Atlantic, eastern Pacific and Indian Oceans in at least 21 cetacean species, with varying prevalence. Two cetacean poxvirus (CePV) clades are recognised: CePV-1 in odontocetes and CePV-2 in mysticetes. CePV-1 isolates were recovered from six Delphinidae and one Phocoenidae in the Americas, Europe and Hong Kong. Strains from Delphinidae are closely related. Among Phocoenidae, poxviruses were sampled only in harbour porpoises around the British Isles. CePV-2 isolates were obtained from southern right whales ( Eubalaena australis ) and a bowhead whale ( Balaena mysticetus ). In healthy animals, an immune response develops over time, with young calves protected by maternal immunity. Salinity and sea surface temperature do not seem to influence TSD prevalence in free-ranging cetaceans. High concentrations of immunotoxic halogenated organochlorines may cause a more severe clinical disease. Substitution and loss of genes involved in anti-viral immunity may favour CePV entry, replication and persistence in the epidermis. Off California, Delphinidae were less often (26.3%) affected by TSD than harbour porpoises (43.6%). Male porpoises were significantly more prone (58.1%) to show clinical disease than females (25%). Among males, TSD affected a high proportion of juveniles and subadults. TSD was not detected in the Kogiidae.

Background: Weddell seals (Leptonychotes weddellii) are a well-studied species of phocid with an apparent sensitivity to immobilising agents. Mortality as high as 31% has been reported during field immobilisation. This study investigated the use of a benzodiazepine in combination with an opioid agonist/antagonist for sedation in Weddell seal pups as part of a physiological study., Methods: During the 2017 and 2019 Antarctic pupping seasons, 18 Weddell seal pups were sedated by intramuscular administration of a combination of midazolam and butorphanol or intravenous midazolam alone. Individuals were sedated at 1, 3, 5 and 7 weeks of age. Naltrexone and flumazenil were used to reverse sedation. The combination was 100% effective in providing appropriate sedation for the intended procedures., Results: Analyses were performed to investigate relationships between dose administered, age, individual reactions, adverse effects and changes in dive physiology. Transient apnoea (10-60 seconds) was the most frequently observed adverse effect. No sedation-associated morbidity or mortality occurred., Limitations: The sample size is small and there is no pharmacokinetic information for either sedative or reversal in phocid species., Conclusions: The combination of midazolam (0.2-0.3 mg/kg) and butorphanol (0.1-0.2 mg/kg) provided safe and effective sedation, with reversible effects, in Weddell seal pups., (© 2022 The Authors. Veterinary Record published by John Wiley & Sons Ltd on behalf of British Veterinary Association.)

Pathology in the dentate gyrus, including sclerosis, is a hallmark of temporal lobe epilepsy, and reduced inhibition to dentate granule cells may contribute to epileptogenesis. The perisomatic-targeting axonal boutons of parvalbumin-expressing interneurons decrease in proportion with granule cells in temporal lobe epilepsy. In contrast, dendrite-targeting axonal boutons of somatostatin-expressing interneurons sprout exuberantly in temporal lobe epilepsy. A third major class of GABAergic interneurons expresses cannabinoid receptor type 1 (CB1) on their terminal boutons, but there is conflicting evidence as to whether these boutons are increased or decreased in temporal lobe epilepsy. Naturally occurring temporal lobe epilepsy in California sea lions, with unilateral or bilateral sclerosis, offers the benefit of neuroanatomy and neuropathology akin to humans, but with the advantage that the entirety of both hippocampi from control and epileptic brains can be studied. Stereological quantification in the dentate gyrus revealed that sclerotic hippocampi from epileptic sea lions had fewer CB1-labeled boutons than controls. However, the reduction in the number of granule cells was greater, resulting in increased CB1-labeled boutons per granule cell in sclerotic hippocampi at temporal levels. This suggests that although CB1-expressing boutons are decreased in sclerotic dentate gyri, surviving cells have enhanced innervation from these boutons in epileptic sea lions., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Nasopulmonary mites (NPMs) of the family Halarachnidae are obligate endoparasites that colonize the respiratory tracts of mammals. NPMs damage surface epithelium resulting in mucosal irritation, respiratory illness, and secondary infection, yet the role of NPMs in facilitating pathogen invasion or dissemination between hosts remains unclear. Using 16S rRNA massively parallel amplicon sequencing of six hypervariable regions (or "16S profiling"), we characterized the bacterial community of NPMs from 4 southern sea otters (Enhydra lutris nereis). This data was paired with detection of a priority pathogen, Streptococcus phocae, from NPMs infesting 16 southern sea otters and 9 California sea lions (Zalophus californianus) using nested conventional polymerase chain reaction (nPCR). The bacteriome of assessed NPMs was dominated by Mycoplasmataceae and Vibrionaceae, but at least 16 organisms with pathogenic potential were detected as well. Importantly, S. phocae was detected in 37% of NPM by nPCR and was also detected by 16S profiling. Detection of multiple organisms with pathogenic potential in or on NPMs suggests they may act as mechanical vectors of bacterial infection for marine mammals., Competing Interests: The authors have declared that no competing interests exist.

Cardiac disease has been extensively documented in marine mammals; however, it remains difficult to diagnose antemortem. Assays measuring cardiac troponin I (cTnI) and N-terminal pro-brain natriuretic peptide (NT-proBNP) are used as sensitive and specific biomarkers of cardiac disease in many species, but have not been widely investigated in marine mammals. This study aimed to provide a set of reference values for cTnI and NT-proBNP in belugas (BW) ( Delphinapterus leucas ), sea otters (SO) ( Enhydra lutris ), Steller sea lions (SSL) ( Eumetopias jubatus ), and California sea lions (CSL) ( Zalophus californianus ) with and without cardiac disease, and to determine if these biomarkers are useful indicators of cardiac disease in these species. First, existing immunoassays for cTnI and NT-proBNP were successfully validated utilizing species-specific heart lysate spiked serum. Cohorts were defined by histopathology as animals with no evidence of cardiac disease ("control"), with confirmed cardiac disease ("disease"), and with concurrent renal and cardiac disease ("renal") for which serum samples were then analyzed. Serum concentration ranges for cTnI (ng/ml) and NT-proBNP (pmol/L) were determined for control and disease cohorts. There was significantly higher cTnI ( P = 0.003) and NT-proBNP ( P = 0.004) concentrations in the CSL disease cohort, as well as positive trends in BW, SO, and SSL disease cohorts that did not reach statistical significance. NT-proBNP concentrations were significantly higher in the CSL renal cohort compared with the control ( P < 0.001) and disease ( P = 0.007) cohorts. These results suggest that cTnI and NT-proBNP may be clinically useful in the antemortem diagnosis of cardiac disease in CSL, and warrant further investigation in BW, SO, and SL.

Two emaciated male northern elephant seal (NES) Mirounga angustirostris pups were admitted to The Marine Mammal Center (Sausalito, California, USA) and treated for malnutrition. Complete blood counts showed a progressive moderate to marked leukocytosis characterized by a predominance of large monomorphic mononuclear cells of probable lymphoid origin, frequently with flower-shaped nuclei. Both seals were euthanized due to suspected lymphoid neoplasia. At necropsy, most lymph nodes in both pups were markedly enlarged, some with distinct white nodules, the spleens were diffusely enlarged, and the intestinal mucosae were thickened. Histopathologic features consistent with disseminated large cell lymphoma were identified to varying degrees of severity in lymph nodes, bone marrow, liver, tonsils, spleen, liver, intestines, kidneys, lower urinary tract, and several other organs. Immunohistochemical staining of neoplastic cells was most consistent with B lymphocyte origin, with most cells staining positively for Pax 5 and CD20 with admixed small CD3-positive T lymphocytes and CD204-positive macrophages. PCR and sequencing identified a novel gammaherpesvirus, herein called miroungine gammaherpesvirus 3, from affected tissues. This virus is in a clade outside of named genera that utilize hosts in the suborder Caniformia. The present study is the first description of diffuse large B cell lymphoma with leukemic manifestation and concomitant detection of a novel gammaherpesvirus in free-living NESs. Further research regarding the prevalence of this new gammaherpesvirus and its associated pathogenesis in this species is indicated.

Mercury (Hg) is a well-known toxicant in wildlife and humans. High total Hg concentrations ([THg]) have been reported in central California harbor seals Phoca vitulina richardii. We evaluated the effects of presence/absence of early natal coat (lanugo), year (2012 to 2017), sex, stranding location, and trophic ecology (ẟ 13 C and ẟ 15 N values) on hair [THg] along coastal central California. Also examined were [THg] effects on growth rates of pups in rehabilitation and probability of release (e.g., successful rehabilitation). The [THg] ranged from 0.46-81.98 mg kg -1 dw, and ẟ 15 N and ẟ 13 C ranged from 13.6-21.5‰, and -17.2 to -13.0‰, respectively. Stranding location, year, and presence of lanugo coat were important factors explaining variation in [THg]. Seals from Sonoma and San Mateo County had higher [THg] than other locations. Seals with full or partial lanugo coat had lower [THg]. Seals from 2016 and 2017 had higher [THg] than those from 2015. Hair [THg] exceeded lower and upper toxicological thresholds (>20 mg kg -1 by year (5.88% to 23.53%); >30 mg kg -1 (0% to 12.31%)) with a pronounced increase from 2015 to 2016. Pups in 2017 had significantly higher odds ratio of [THg] above 20 mg kg -1 than pups of 2015, and pups in 2016 had significantly higher odds ratio than those from 2013 and 2015 (similar when using 30 mg kg -1 ). Pups in Sonoma County had the highest odds ratio for [THg] in lanugo above 20 mg kg -1 . ẟ 15 N values were higher in 2015-2017, particularly relative to 2014, probably associated with the El Niño event. The [THg] was not a good predictor for probability of release and mass-specific growth rates in captivity. Further investigation of temporal trends of [THg] in harbor seals is warranted given the relatively high percentage of samples exceeding threshold values, particularly in the most recent sampling years., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Temporal trends of polybrominated diphenyl ethers (PBDEs) have been extensively studied in various environmental compartments globally. However, despite the increasing use of alternative flame retardants following PBDE bans, the spatiotemporal trends of these replacements have rarely been studied, and the available results are often inconsistent. In the present study, we retrospectively investigated the spatiotemporal trends of PBDEs and a suite of alternative brominated FRs (aBFRs) and chlorinated FRs ( i.e. , dechloranes or DECs) in three harbor seal ( Phoca vitulina ) populations from the coasts of California, the Gulf of Maine, and southern Sweden during 1999-2016. We observed significantly decreasing trends of ΣPBDEs in all the three populations at an annual rate of 9-11%, which were predominantly driven by the declining concentrations of tetra- and penta-BDEs. The levels of ΣaBFRs decreased significantly in seals from California (mainly 1,3,5-tribromobenzene) and Sweden (mainly hexabromobenzene), while no trend was observed for those from Maine. By contrast, DECs (dominated by DEC 602) did not decrease significantly in any population. Compared with the consistent PBDE congener profiles across regions, aBFRs and DECs exhibited varying compositional profiles between regions, likely indicating region-specific sources of these alternative FR mixtures. Spatial analysis also revealed regional differences in the concentrations of PBDEs, aBFRs, and DECs in harbor seals. Our reconstructed spatiotemporal trends suggest the effective regulation of commercial penta-BDE mix in these regions and warrant further monitoring of the higher brominated BDEs and alternative FRs.

Southern sea otters (SSO: Enhydra lutris nereis) are a federally-listed threatened subspecies found almost exclusively in California, USA. Despite their zoonotic potential and lack of host specificity, K. pneumoniae and Klebsiella spp. have largely unknown epizootiology in SSOs. Klebsiella pneumoniae is occasionally isolated at necropsy, but not from live SSOs. Hypermucoviscous (HMV) K. pneumoniae strains are confirmed pathogens of Pacific Basin pinnipeds, but have not been previously isolated from SSOs. We characterized the virulence profiles of K. pneumoniae isolates from necropsied SSOs, evaluated killing of marine mammal K. pneumoniae following in vitro exposure to California sea lion (CSL: Zalophanus californianus) whole blood and serum, and characterized lesion patterns associated with Klebsiella spp. infection in SSOs. Four of 15 SSO K. pneumoniae isolates were HMV and all were recovered from SSOs that stranded during 2005. Many K. pneumoniae infections were associated with moderate to severe pathology as a cause of death or sequela. All HMV infections were assessed as a primary cause of death or as a direct result of the primary cause of death. Klebsiella-infected SSOs exhibited bronchopneumonia, tracheobronchitis and/or pleuritis, enteritis, Profilicollis sp. acanthocephalan peritonitis, septic peritonitis, and septicemia. All SSO HMV isolates were capsular type K2, the serotype most associated with HMV infections in CSLs. Multiplex PCR revealed two distinct virulence gene profiles within HMV isolates and two within non-HMV isolates. In vitro experiments investigating CSL whole blood and serum killing of K. pneumoniae suggest that HMV isolates are more resistant to serum killing than non-HMV isolates., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Enteritis is a common cause of morbidity and mortality in lorikeets that can be challenging to diagnose and treat. In this study, we examine gut microbiota in two lorikeet flocks with enteritis (Columbus Zoo and Aquarium-CZA; Denver Zoo-DZ). Since 2012, the CZA flock has experienced repeated outbreaks of enteritis despite extensive diet, husbandry, and clinical modifications. In 2018, both CZA and DZ observed a spike in enteritis. Recent research has revealed that the gut microbiota can influence susceptibility to enteropathogens. We hypothesized that a dysbiosis, or alteration in the gut microbial community, was making some lorikeets more susceptible to enteritis, and our goal was to characterize this dysbiosis and determine the features that predicted susceptibility., Results: We employed 16S rRNA sequencing to characterize the cloacal microbiota in lorikeets (CZA n = 67, DZ n = 24) over time. We compared the microbiota of healthy lorikeets, to lorikeets with enteritis, and lorikeets susceptible to enteritis, with "susceptible" being defined as healthy birds that subsequently developed enteritis. Based on sequencing data, culture, and toxin gene detection in intestinal contents, we identified Clostridium perfringens type A (CZA and DZ) and C. colinum (CZA only) at increased relative abundances in birds with enteritis. Histopathology and immunohistochemistry further identified the presence of gram-positive bacilli and C. perfringens, respectively, in the necrotizing intestinal lesions. Finally, using Random Forests and LASSO models, we identified several features (young age and the presence of Rhodococcus fascians and Pseudomonas umsongensis) associated with susceptibility to clostridial enteritis., Conclusions: We identified C. perfringens type A and C. colinum associated with lorikeet necrohemorrhagic enteritis at CZA and DZ. Susceptibility testing of isolates lead to an updated clinical treatment plan which ultimately resolved the outbreaks at both institutions. This work provides a foundation for understanding gut microbiota features that are permissive to clostridial colonization and host factors (e.g. age, prior infection) that shape responses to infection., (© 2022. The Author(s).)

Erysipelothrix rhusiopathiae was detected immunohistochemically in contagious ecthyma (orf virus) dermatitis in two muskoxen (Ovibos moschatus), harvested and found dead in 2014 and 2015, respectively, on Victoria Island, Canada. This may help target further research on E. rhusiopathiae epidemiology and mechanisms of infection in muskoxen, recently associated with widespread mortalities in Canada's Arctic., (© Wildlife Disease Association 2022.)

Recent studies have sought to optimize the fecal flotation procedure to improve the detection of helminth eggs in terrestrial domestic species. It is unclear, however, whether these efforts in optimization are applicable to parasite species of marine environments, and verification of veterinary diagnostic procedures is clinically important. It was hypothesized that the eggs belonging to the parasites of pinnipeds would have different specific gravities (SpG) than those belonging to terrestrial hosts. Fecal samples were collected from each of 25 stranded pinnipeds representing three species ( Zalophus californianus , Phoca vitulina , Mirounga angustirostris ), and modified double centrifugal flotations were performed on 1-g samples. Among the 22 California sea lions sampled, trematode, ascarid, and cestode eggs were detected in 17/22 (77%), 10/22 (45%), and 4/22 (18%) individuals, respectively. Sugar-gradient modified centrifugation flotations were then conducted on a subset of 10 samples from California sea lions to evaluate the distribution of eggs in fractions representing varying SpG. Higher numbers of ascarid eggs were found in fractions representing a lower SpG (1.00-1.15), whereas trematode eggs belonging to the genus Zalophotrema were found in significantly higher numbers in the fraction representing 1.25 ( P < 0.05). In conclusion, the SpG of trematode, ascarid, and cestode eggs from pinnipeds appears to be similar to those from terrestrial hosts, but numerous factors may affect their ability to be detected using traditional diagnostic approaches. Further exploration into the nature of the variability noted may lead to improved diagnostics in marine parasitology.

Domoic acid (DA) is a potent neurotoxin produced by certain marine algae that can cause neurologic and cardiac dysfunction by activating glutamate receptors. Glutamate receptor overexcitation results in continuous cellular activation, oxidative damage, and cell death. DA toxicosis causes disorientation and seizures, and antiseizure medications are the primary treatment. Alpha lipoic acid (ALA), a powerful antioxidant and glutathione precursor widely used in humans and dogs, can cross the blood-brain barrier to provide antioxidant availability to brain tissue. Hundreds of stranded California sea lions (CSL; Zalophus californianus ) are diagnosed annually with DA toxicosis and thus are an appropriate animal in which to establish ALA dosing recommendations for treatment. The objective of this study was to determine the population pharmacokinetics of a single 10- or 20-mg/kg dose of ALA administered subcutaneously into the interscapular region to healthy rehabilitated CSL. Blood was collected at two time points between 15 min and 24 h after administration. Serum ALA concentrations were measured by liquid chromatography-mass spectrometry, and parameters were evaluated using a nonlinear mixed effects model. ALA was rapidly absorbed for each dose, peaking within 20 to 30 minutes, and t 1/2 of 40 and 32 min (10 and 20 mg/kg, respectively), followed by an initial steep distribution phase and prolonged elimination phase. Peak concentration (C MAX ) was 1,243 ng/ml (10-mg/ml dose) and 5,010 ng/ml (20-mg/ml dose). Serum from 13 CSLd with DA toxicosis treated with 10 mg/kg ALA for 1 to 9 d had measurable levels, and ALA was also measurable in cerebrospinal fluid from two treated CSLs. Therapeutic effects are noted with a C MAX of 4,000 to 5,000 ng/ml in humans; thus in CSLs, 20 mg/kg administered subcutaneously once daily may be sufficient to achieve a therapeutic level in this species. Determination of efficacy and optimal dosing interval and duration require additional investigation.

Hypotension is a common adverse effect of general anesthesia that has historically been difficult to measure in pinniped species due to technical challenges. A retrospective case review found seven pinniped cases that demonstrated anesthesia-associated hypotension diagnosed by direct blood pressure measurements during general anesthesia at The Marine Mammal Center (Sausalito, CA) between 2017 and 2019. Cases included five California sea lions (CSL: Zalophus californianus ), one Hawaiian monk seal (HMS: Neomonachus schauinslandi ), and one northern elephant seal (NES: Mirounga angustirostris ). Patients were induced using injectable opioids, benzodiazepines, and anesthetics including propofol and alfaxalone. Excluding the HMS, all patients required supplemental isoflurane with a mask to achieve an anesthetic plane allowing for intubation. Each patient was maintained with inhalant isoflurane in oxygen for the duration of the anesthetic event. Each patient was concurrently administered continuous IV fluids and four patients received fluid boluses prior to administration of ephedrine. All hypotensive anesthetized patients were treated with IV ephedrine (0.05-0.2 mg/kg). The average initial systolic (SAP) and mean (MAP) arterial blood pressures for the CSL prior to ephedrine administration were 71 ± 14 mmHg and 48 ± 12 mmHg respectively. The average SAP and MAP for the CSL increased to 119 ± 32 mmHg and 90 ± 34 mmHg respectively within 5 m of ephedrine administration. The NES initial blood pressure measurement was 59/43 (50) (SAP/diastolic [MAP]) mmHg and increased to 80/51 (62) mmHg within 5 m. The initial HMS blood pressure was 79/68 (73) mmHg and increased to 99/78 (85) mmHg within 5 m following ephedrine administration. All patients recovered from anesthesia. These results support the efficacy of IV ephedrine for the treatment of anesthesia-associated hypotension in pinnipeds.

Mites from the family Halarachnidae Oudemans 1906 are obligate endoparasites that colonize the respiratory tracts of free-living and captive marine mammals. Infestations can range from mild to severe and result in respiratory tract irritation or impairment. Nasopulmonary acariasis was determined to be a contributing cause of death among several southern sea otters Enhydra lutris nereis Merriam 1904 in a longitudinal study of otter mortality, and proximity to Pacific harbor seals Phoca vitulina richardii Gray 1864 was a significant risk factor for sea otter infestation. Beyond scattered opportunistic reports, each halarachnid mite species' affinity for particular hosts and the extent of mite transmission between host species is poorly understood. We investigated the identity and prevalence of nasopulmonary mites from Pacific harbor seals, California sea lions Zalophus californianus Lesson 1828, northern elephant seals Mirounga angustirostris Gill 1866, northern fur seals Callorhinus ursinus Linnaeus 1758, and Guadalupe fur seals Arctocephalus philippii townsendi Merriam 1897 to complement published nasopulmonary mite findings from sympatric southern sea otters during a comparable timeframe. Halarachnid mite infestation was common among California sea lions (74.1%), northern fur seals (73.3%), and northern elephant seals (46.6%), but was less common among harbor seals (18.7%) and Guadalupe fur seals (8.8%). Observed host-mite relationships suggest a distinct host specificity, with genus Orthohalarachne infesting otariids, and genus Halarachne infesting phocids and lutrinids along the California coast. Harbor seals and southern sea otters were the primary hosts of H. halichoeri , but one nothern elephant seal was infested with both H. miroungae and a single H. halichoeri. We also present the first high-resolution SEM images for H. miroungae and O. attenuata and possible evidence for a new host record for H. halichoeri ., Competing Interests: None., (© 2021 The Authors.)

To understand susceptibility of wild California sea lions and Northern elephant seals to influenza A virus (IAV), we developed an ex vivo respiratory explant model and used it to compare infection kinetics for multiple IAV subtypes. We first established the approach using explants from colonized rhesus macaques, a model for human IAV. Trachea, bronchi, and lungs from 11 California sea lions, 2 Northern elephant seals, and 10 rhesus macaques were inoculated within 24 h postmortem with 6 strains representing 4 IAV subtypes. Explants from the 3 species showed similar IAV infection kinetics, with peak viral titers 48 to 72 h post-inoculation that increased by 2 to 4 log 10 PFU/explant relative to the inoculum. Immunohistochemistry localized IAV infection to apical epithelial cells. These results demonstrate that respiratory tissue explants from wild marine mammals support IAV infection. In the absence of the ability to perform experimental infections of marine mammals, this ex vivo culture of respiratory tissues mirrors the in vivo environment and serves as a tool to study IAV susceptibility, host range, and tissue tropism. IMPORTANCE Although influenza A virus can infect marine mammals, a dearth of marine mammal cell lines and ethical and logistical challenges prohibiting experimental infections of living marine mammals mean that little is known about IAV infection kinetics in these species. We circumvented these limitations by adapting a respiratory tract explant model first to establish the approach with rhesus macaques and then for use with explants from wild marine mammals euthanized for nonrespiratory medical conditions. We observed that multiple strains representing 4 IAV subtypes infected trachea, bronchi, and lungs of macaques and marine mammals with variable peak titers and kinetics. This ex vivo model can define infection dynamics for IAV in marine mammals. Further, use of explants from animals euthanized for other reasons reduces use of animals in research.

During the 2018 breeding season, an outbreak of respiratory disease occurred among Galapagos sea lions (Zalophus wollebaeki) that inhabit rookeries near urban areas with introduced fauna such as dogs and cats. Several sea lions had nasal discharge and respiratory distress and were in poor body condition. Eighteen sea lions were captured for a general health assessment including collection of blood for serology and nasal discharge for culture and PCR. Samples were analyzed for 15 respiratory pathogens known to infect cats, dogs, and marine mammals. There was no evidence for interspecies pathogen transmission between Galapagos sea lions and domestic animals. Several bacterial pathogens associated with respiratory tract infection in the California sea lion (Zalophus californianus) were isolated. Mycoplasma spp. were identified by PCR in nasal discharge samples but were not the species commonly found in cats and dogs., (© Wildlife Disease Association 2021.)

Objective: To compare serum cardiac troponin I (cTnI) concentrations between sea otters with and without cardiomyopathy and describe 2 cases of cardiomyopathy with different etiologies., Animals: 25 free-ranging southern sea otters (Enhydra lutris nereis) with (n = 14; cases) and without (11; controls) cardiomyopathy and 17 healthy managed southern sea otters from aquariums or rehabilitation centers (controls)., Procedures: Serum cTnI concentration was measured in live sea otters. Histopathologic and gross necropsy findings were used to classify cardiomyopathy status in free-ranging otters; physical examination and echocardiography were used to assess health status of managed otters. Two otters received extensive medical evaluations under managed care, including diagnostic imaging, serial cTnI concentration measurement, and necropsy., Results: A significant difference in cTnI concentrations was observed between cases and both control groups, with median values of 0.279 ng/mL for cases and < 0.006 ng/mL for free-ranging and managed controls. A cutoff value of ≥ 0.037 ng/mL yielded respective sensitivity and specificity estimates for detection of cardiomyopathy of 64.3% and 90.9% for free-ranging cases versus free-ranging controls and 64.3% and 94.1% for free-ranging cases versus managed controls., Conclusions and Clinical Relevance: Cardiomyopathy is a common cause of sea otter death that has been associated with domoic acid exposure and protozoal infection. Antemortem diagnostic tests are needed to identify cardiac damage. Results suggested that serum cTnI concentration has promise as a biomarker for detection of cardiomyopathy in sea otters. Serial cTnI concentration measurements and diagnostic imaging are recommended to improve heart disease diagnosis in managed care settings.

Information about antemortem cardiac evaluation in sea otters ( Enhydra lutris ) is limited, despite well-established clinical care and rehabilitation procedures and a reported elevated risk of cardiac disease for this species. Serum cardiac troponin I (cTnI) concentration and echocardiographic assessment are two ways of screening for and diagnosing cardiac disease. However, no baseline data or reference intervals for either evaluation are published for sea otters. The objectives of this prospective study were to establish serum cTnI concentrations and echocardiographic technique and quantitative measurements in anesthetized healthy female southern sea otters ( Enhydra lutris nereis ) ( n =15). Serum cTnI values were assessed by a high-sensitivity assay. Serum cTnI concentration ranged from <0.006 to 0.038 ng/ml. A complete echocardiogram, including two-dimensional and M-mode modalities, was performed. Echocardiographic measurements for left atrial size, aorta size, left ventricular structure, and left ventricular function were reported. The median left atrial size to aorta ratio was 1.22 (range 0.80-1.59) in short-axis and 1.70 (range 1.39-2.15) in long-axis. The median left ventricular internal dimension was 3.53 cm (range 2.87-4.92 cm) when assessed in two dimensions and 3.58 cm (range 2.80-4.48 cm) by M-mode. Serum concentrations of cTnI and transthoracic echocardiography may represent valuable tools for the antemortem diagnosis of cardiac disease in sea otters.

Background: Southern sea otters (Enhydra lutris nereis) rely on intact pelage for thermoregulation, and thus clinically significant demodicosis and associated alopecia can cause morbidity and death., Hypothesis/objectives: This study aimed to describe lesions associated with follicular Demodex sp. infestation, estimate the prevalence and intensity of infestation, describe mite distribution across key anatomical regions, and assess mite presence or absence in relation to lesions and host risk factors., Animals: Twenty necropsied, wild southern sea otters that stranded along the central California coast from 2005 to 2018., Methods and Materials: Grossly normal and abnormal integument from the head, perineum, genitals, mamillary papillae and limbs was assessed microscopically for mites and mite-associated pathological findings., Results: Intrafollicular mites were observed in the integument of 55% of otters and 20% had clinical demodicosis. Demodicosis was considered to be contributory to death or euthanasia in two cases. Although Demodex sp. mites often were observed microscopically in grossly normal skin, the presence of multiple densely-packed intrafollicular mites generally was associated with pigmentary incontinence, ectatic follicles, lymphoplasmacytic perifolliculitis, and neutrophilic and lymphoplasmacytic, dermal inflammation. Other findings included epidermal hyperplasia, orthokeratotic hyperkeratosis of epidermis and follicular epithelium, concurrent pyoderma and cell necrosis. Perioral integument, especially of the chin, had the highest prevalence of mites and the highest mite density, suggesting facial contact as a means of mite transmission., Conclusions and Clinical Importance: Our research confirmed demodectic mange as a contributor to morbidity and mortality in sea otters, with important implications for clinical care, rehabilitation and conservation., (© 2021 ESVD and ACVD.)

Parapoxviruses cause nodular lesions on the skin and mucosal membranes of pinnipeds and infections by these viruses have been documented worldwide. Seal parapoxvirus is currently classified as a tentative species of the Parapoxvirus genus. Tissue or swab samples were analyzed from 11 pinnipeds of different host species undergoing rehabilitation on the east and west coasts of the United States of America (USA) that were positive for parapoxvirus. The aim of the study was to compare parapoxvirus sequences of fragments of the B2L, DNA polymerase, GIF and viral interleukin-10 ortholog ( vIL-10) genes and to examine the evolutionary relationship between viruses detected in different pinniped species and at different locations with other members of the Parapoxvirus genus, such as Orf virus (ORFV), Bovine papular stomatitis virus (BPSV) and Pseudocowpox virus (PCPV). The sequence analysis showed that the parapoxvirus sequences from the pinnipeds differed significantly from those found in terrestrial hosts and that they formed a separate cluster within the genus. Our results suggest that transmission of the same parapoxvirus strain is possible between different species, including between members of different families (phocids and otariids). Animals belonging to the same species but living in distant geographic locations presented genetically distant parapoxviruses. The findings of this study demonstrate that sealpox lesions in pinnipeds of different species are caused by viruses that belong to the Parapoxvirus genus but have significant genetic differences compared to the established virus species in terrestrial hosts, thus strongly supporting the classification of pinniped parapoxvirus as a new species of the genus., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Costa, Klein, Breines, Nollens, Matassa, Garron, Duignan, Schmitt, Goldstein and Tryland.)

The spirochete bacterium Leptospira interrogans serovar Pomona is enzootic to California sea lions (CSL; Zalophus californianus ) and causes periodic epizootics. Leptospirosis in CSL is associated with a high fatality rate in rehabilitation. Evidence-based tools for estimating prognosis and guiding early euthanasia of animals with a low probability of survival are critical to reducing the severity and duration of animal suffering. Classification and regression tree (CART) analysis of clinical data was used to predict survival outcomes of CSL with leptospirosis in rehabilitation. Classification tree outputs are binary decision trees that can be readily interpreted and applied by a clinician. Models were trained using data from cases treated from 2017 to 2018 at The Marine Mammal Center in Sausalito, CA, and tested against data from cases treated from 2010 to 2012. Two separate classification tree analyses were performed, one including and one excluding data from euthanized animals. When data from natural deaths and euthanasias were included in model-building, the best classification tree predicted outcomes correctly for 84.7% of cases based on four variables: appetite over the first 3 days in care, and blood urea nitrogen (BUN), creatinine, and sodium at admission. When only natural deaths were included, the best model predicted outcomes correctly for 87.6% of cases based on BUN and creatinine at admission. This study illustrates that CART analysis can be successfully applied to wildlife in rehabilitation to establish evidence-based euthanasia criteria with the goal of minimizing animal suffering. In the context of a large epizootic that challenges the limits of a facility's capacity for care, the models can assist in maximizing allocation of resources to those animals with the highest predicted probability of survival. This technique may be a useful tool for other diseases seen in wildlife rehabilitation.

Background: Domoic acid (DOM) is a neurotoxin produced by some harmful algae blooms in coastal waters. California sea lions (Zalophus californianus) exposed to DOM often strand on beaches where they exhibit a variety of symptoms, including seizures. These animals typically show hippocampal atrophy on MRI scans., New Method: We describe an MRI protocol for comprehensive evaluation of DOM toxicosis in the sea lion brain. We intend to study brain development in pups exposed in utero. The protocol depicts the hippocampal formation as the primary region of interest. We include scans for quantitative morphometry, functional and structural connectivity, and a cerebral blood flow map., Results: High-resolution 3D anatomical scans facilitate post hoc slicing in arbitrary planes and accurate morphometry. We demonstrate the first cerebral blood flow map using MRI, and the first structural tractography from a live sea lion brain., Comparison With Existing Methods: Scans were compared to prior anatomical and functional studies in live sea lions, and structural connectivity in post mortem specimens. Hippocampal volumes were broadly in line with prior studies, with differences likely attributable to the 3D approach used here. Functional connectivity of the dorsal left hippocampus matched that found in a prior study conducted at a lower magnetic field, while structural connectivity in the live brain agreed with findings observed in post mortem studies., Conclusions: Our protocol provides a comprehensive, longitudinal view of the functional and anatomical changes expected to result from DOM toxicosis. It can also screen for other common neurological pathologies and is suitable for any pinniped that can fit inside an MRI scanner., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Monomethyl mercury (MeHg + ) from the diet can cause mild to severe neurotoxicosis in fish-eating mammals. Chronic and low-level in utero exposure also can be neurotoxic, as documented in laboratory animal studies and epidemiologic investigations. In free-ranging animals, it is challenging to study low-level exposure related neurotoxicosis, and few studies have investigated the relationship between mercury (Hg) and adverse outcomes in wild populations. Relative to Hg concentrations on admission we evaluated different types of behaviors for 267 Pacific harbor seal (HS; Phoca vitulina richardii) pups at The Marine Mammal Center from 2015 to 2019 during rehabilitation after stranding and maternal separation. Admitted HS pups underwent a clinical exam; including sex and weight determination, and hair (partly lanugo grown in utero) and blood samples were collected for total Hg concentration ([THg]) determination. All pups were monitored weekly (behavior assessments included response to tactile stimulation, movement, swimming, interactions with other seals, hand feeding, and feeding independently), and days in rehabilitation and survival were recorded. There was a significant negative correlation between [THg] and responses to tactile stimulation and movements, measured in both hair and whole blood (p < 0.05). This relationship was found both during the intensive care unit (ICU) stage, and during the pool stage of rehabilitation. Additionally, there was a significant association between greater [THg] and number of days spent in rehabilitation, although there was no relationship between [THg] and survival. There was a significant sex difference, with greater [THg] in female pups, which contrasts with previously published findings in juvenile and adult harbor seals. Our findings support small, but significant associations between gestational THg exposure and clinical effects for tactile sensory response and movement, and longer rehabilitation durations for HS pups, although there was considerable variability among animals., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

High allelic polymorphism and association with disease susceptibility has made the genes encoding major histocompatibility complex (MHC) antigen presentation molecules in humans, domesticated animals, and wildlife species of wide interest to ecologists, evolutionary biologists, and health specialists. The often multifaceted polygenism and extreme polymorphism of this immunogenetic system have made it especially difficult to characterize in non-model species. Here we compare and contrast the workflows of traditional Sanger sequencing of plasmid-cloned amplicons to Pacific Biosciences SMRT circular consensus sequencing (CCS) in their ability to capture alleles of MHC class I in a wildlife species where characterization of these genes was absent. We assessed two California sea lions (Zalophus californianus), a species suffering from a high prevalence of an aggressive cancer associated with a sexually transmitted gamma herpesvirus. In this pilot study, SMRT CCS proved superior in identifying more alleles from each animal than the more laborious plasmid cloning/Sanger workflow (12:7, 10:7), and no alleles were identified with the cloning/Sanger approach that were not identified by SMRT CCS. We discuss the advantages and disadvantages of each approach including cost, allele rarefaction, and sequence fidelity., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Urogenital carcinoma in California sea lions ( Zalophus californianus ) is the most common cancer of marine mammals. Primary tumors occur in the cervix, vagina, penis, or prepuce and aggressively metastasize resulting in death. This cancer has been strongly associated with a sexually transmitted herpesvirus, otarine herpesvirus 1 (OtHV1), but the virus has been detected in genital tracts of sea lions without cancer and a causative link has not been established. To determine if OtHV1 has a role in causing urogenital carcinoma we sequenced the viral genome, quantified viral load from cervical tissue from sea lions with ( n = 95) and without ( n = 163) urogenital carcinoma, and measured viral mRNA expression using in situ mRNA hybridization (Basescope ® ) to quantify and identify the location of OtHV1 mRNA expression. Of the 95 sea lions diagnosed with urogenital carcinoma, 100% were qPCR positive for OtHV1, and 36% of the sea lions with a normal cervix were positive for the virus. The non-cancer OtHV1 positive cases had significantly lower viral loads in their cervix compared to the cervices from sea lions with urogenital carcinoma. The OtHV1 genome had several genes similar to the known oncogenes, and RNA in situ hybridization demonstrated high OtHV1 mRNA expression within the carcinoma lesions but not in normal cervical epithelium. The high viral loads, high mRNA expression of OtHV1 in the cervical tumors, and the presence of suspected OtHV1 oncogenes support the hypothesis that OtHV1 plays a significant role in the development of sea lion urogenital carcinoma.

A distinct ulcerative dermatitis known as "freshwater skin disease" is an emerging clinical and pathological presentation in coastal cetaceans worldwide. In Australia, two remarkably similar mortality events enabled the creation of a case definition based on pathology and environmental factors. The first affected a community of endemic Tursiops australis in the Gippsland Lakes, Victoria, while the second occurred among T. aduncus resident in the Swan-Canning River system, Western Australia. The common features of both events were (1) an abrupt and marked decrease in salinity (from > 30ppt to < 5ppt) due to rainfall in the catchments, with hypo-salinity persisting weeks to months, and (2) dermatitis characterized grossly by patchy skin pallor that progressed to variable circular or targetoid, often raised, and centrally ulcerated lesions covering up to 70% of the body surface. The affected skin was often colonized by a variety of fungal, bacterial and algal species that imparted variable yellow, green or orange discoloration. Histologic lesions consisted of epidermal hydropic change leading to vesiculation and erosion; alternately, or in addition, the formation of intra-epithelial pustules resulting in ulceration and hypodermal necrosis. Thus, the environmental factors and characteristic pathologic lesions, are necessary components of the case definition for freshwater skin disease.

Mammals with increased requirements for adipose tissue stores, such as marine mammals, have altered nutrient allocation priorities compared to many terrestrial mammals and thus the physiological response to undernutrition (low nutritional status) and realimentation (refeeding) may differ. Key regulators of nutrient allocation and tissue specific growth include metabolic hormones of the somatotropic axis, growth hormone (GH) and insulin-like growth factor (IGF)-I, as well as satiety and adipose promoting ghrelin and the stress hormone cortisol. Longitudinal measurements of metabolic hormones, blood metabolites, and morphometrics were collected over a 10-week period in twelve (male n = 3, female n = 9) harbor seal pups (< 6 weeks of age). Blood metabolites were used to indicate metabolic response during realimentation while morphometrics estimated tissue specific growth priorities. Harbor seal pups undergoing refeeding after nutritional deprivation show a preference for protein sparing despite severe malnutrition. Both BUN and total protein were negatively associated with GH and positively associated with IGF-I and ghrelin highlighting the importance of these metabolic hormones in the regulation of protein metabolism. While the response of the somatotropic axis to realimentation was typical of the mammalian pattern, the surprising increase of ghrelin across the study period suggests the priority of adipose accretion in addition to a possible mechanism regulating compensatory growth of vital adipose stores in a species, which prioritizes adipose accretion for survival.

The objective of this study was to establish a single-dose pharmacokinetic profile for orally administered itraconazole in California sea lions (Zalophus californianus). Twenty healthy rehabilitated juvenile California sea lions were included in this study. Itraconazole capsules were administered orally with food at a target dose of 5-10 mg/kg. Blood samples were collected from each animal at 0 hr and at two of the following timepoints: 0.5, 1, 2, 4, 6, 8, 12, 24, 48, and 72 hr. Quantitative analysis of itraconazole in plasma samples was performed by high-performance liquid chromatography. An average maximum concentration of 0.22 µg/ml ± 0.11 was detected 4 hr after administration. The average concentration fell to 0.12 µg/ml ± 0.11 by 6 hr and 0.02 µg/ml ± 0.02 at 12 hr. At no point did concentrations reach 0.5 µg/ml, the concentration commonly accepted for therapeutic efficacy. While this formulation was well tolerated by the sea lions, oral absorption was poor and highly variable among individuals. These data indicate that a single oral dose of itraconazole given as a capsule at 5-10 mg/kg, under the conditions used in this study, does not achieve therapeutic plasma concentrations in California sea lions., (© 2020 John Wiley & Sons Ltd.)

Confronted with the challenge of understanding population-level processes, disease ecologists and epidemiologists often simplify quantitative data into distinct physiological states (e.g. susceptible, exposed, infected, recovered). However, data defining these states often fall along a spectrum rather than into clear categories. Hence, the host-pathogen relationship is more accurately defined using quantitative data, often integrating multiple diagnostic measures, just as clinicians do to assess their patients. We use quantitative data on a major neglected tropical disease (Leptospira interrogans) in California sea lions (Zalophus californianus) to improve individual-level and population-level understanding of this Leptospira reservoir system. We create a "host-pathogen space" by mapping multiple biomarkers of infection (e.g. serum antibodies, pathogen DNA) and disease state (e.g. serum chemistry values) from 13 longitudinally sampled, severely ill individuals to characterize changes in these values through time. Data from these individuals describe a clear, unidirectional trajectory of disease and recovery within this host-pathogen space. Remarkably, this trajectory also captures the broad patterns in larger cross-sectional datasets of 1456 wild sea lions in all states of health but sampled only once. Our framework enables us to determine an individual's location in their time-course since initial infection, and to visualize the full range of clinical states and antibody responses induced by pathogen exposure. We identify predictive relationships between biomarkers and outcomes such as survival and pathogen shedding, and use these to impute values for missing data, thus increasing the size of the useable dataset. Mapping the host-pathogen space using quantitative biomarker data enables more nuanced understanding of an individual's time course of infection, duration of immunity, and probability of being infectious. Such maps also make efficient use of limited data for rare or poorly understood diseases, by providing a means to rapidly assess the range and extent of potential clinical and immunological profiles. These approaches yield benefits for clinicians needing to triage patients, prevent transmission, and assess immunity, and for disease ecologists or epidemiologists working to develop appropriate risk management strategies to reduce transmission risk on a population scale (e.g. model parameterization using more accurate estimates of duration of immunity and infectiousness) and to assess health impacts on a population scale., Competing Interests: The authors have declared that no competing interests exist.