Publications by authors named "Michael J Adkesson"

Otariid gammaherpesvirus 1 (OtGHV1) is associated with high rates of urogenital carcinoma in free-ranging California sea lions (Zalophus californianus; CSL), and until recently was reported only in the Northern Hemisphere. The objective of this study was to survey free-ranging South American sea lions (Otaria byronia; SASL) and South American fur seals (Arctocephalus australis: SAFS) in Punta San Juan, Peru for OtGHV1 and to determine prevalence characteristics. Twenty-one percent (14/67) of urogenital swabs collected over three years (2011, 2014, 2015) from live pinnipeds of both species tested positive with a pan-herpesvirus conventional PCR.

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Humboldt Penguin (Spheniscus humboldti) population declines are attributable to several multifaceted anthropogenic impacts. At present, the exposure of Humboldt Penguins to high concentrations of heavy metals in the marine environment is a preeminent concern, due to mining along the Peruvian coast near key rookery sites. Metal and selenium concentrations were determined in eggs collected from September 2020 to April 2021 from a managed-care penguin population at the Brookfield Zoo to establish reference values for health indices conducted on wild populations.

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The Humboldt penguin () population at the Punta San Juan Marine Protected Area in Peru is considered critical to the long-term sustainability of this endangered species in Peru. Exposure of the rookery to environmental toxicants is a mounting concern because of regional growth of industries and human populations. Whole blood samples were collected from 30 free-ranging penguins in 2011 as part of a broader population health monitoring program.

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An intense public debate has fuelled governmental bans on marine mammals held in zoological institutions. The debate rests on the assumption that survival in zoological institutions has been and remains lower than in the wild, albeit the scientific evidence in support of this notion is equivocal. Here, we used statistical methods previously applied to assess historical improvements in human lifespan and data on 8864 individuals of four marine mammal species (harbour seal, ; California sea lion, ; polar bear, ; common bottlenose dolphin, ) held in zoos from 1829 to 2020.

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Article Synopsis
  • Systemic isosporosis is a serious disease affecting juvenile passerine birds, and current treatment methods are inconsistent in effectiveness.
  • This study examined the pharmacokinetics and pharmacodynamics of ponazuril as a treatment, administering it in various ways to 72 European starlings, with the highest plasma concentration achieved through top-dressed feed.
  • Results showed that while ponazuril treatment decreased fecal shedding of the parasite in some birds, shedding resumed after the treatment ended, indicating a temporary reduction in infection risk for juvenile birds.
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South American sea lions (Otaria byronia) and Peruvian fur seals (Arctocephalus australis) are sympatric species inhabiting the coastal Peruvian marine ecosystem. Declining abundance has prompted population health monitoring programs, including temporal monitoring of blood parameters. Several methods exist to determine total leukocyte count, yet no studies have evaluated agreement between methods in pinnipeds.

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Infections with herpesvirus have contributed to respiratory, enteric, and neurological disease reports in avian species worldwide. Herpesviruses have been detected in penguin species before but have not been studied extensively. To better understand the impact of these viruses in free-living populations, an initial retrospective survey was performed on a wild population of Humboldt penguins () in the Punta San Juan Marine Protected Area, Peru (15°22'S, 75°12'W) using tracheal swabs collected from 28 penguins in 2016 and 34 penguins in 2018.

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Death due to illegal trade and trafficking serves as the largest threat to pangolins in their geographic range countries. Appropriate veterinary care is essential to the welfare of sick or debilitated pangolins. Given the challenge of comprehensive physical examination of this species due to its unique anatomic features and poorly studied physiology, laboratory diagnostics can provide essential information to guide appropriate medical care.

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Determining trophic habits of predator communities is essential to measure interspecific interactions and response to environmental fluctuations. South American fur seals, Arctocephalus australis (SAFS) and sea lions Otaria byronia (SASL), coexist along the coasts of Peru. Recently, ocean warming events (2014-2017) that can decrease and impoverish prey biomass have occurred in the Peruvian Humboldt Current System.

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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has a worldwide distribution in humans and many other mammalian species. In late September 2021, 12 animals maintained by the Chicago Zoological Society's Brookfield Zoo were observed with variable clinical signs. The Delta variant of SARS-CoV-2 was detected in faeces and nasal swabs by qRT-PCR, including the first detection in animals from the families Procyonidae and Viverridae.

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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) (), sea otters (SO) (), Steller sea lions (SSL) (), and California sea lions (CSL) () with and without cardiac disease, and to determine if these biomarkers are useful indicators of cardiac disease in these species.

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Three juvenile (<1 yr of age), genetically related Amur leopards () were diagnosed with phimosis. In all cases, no clinical signs were identified, and phimosis was detected during routine examination. Surgical enlargement of the preputial orifice was performed successfully using carbon dioxide laser with a 0.

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Ocular disease in pinnipeds under human care is well described, and intraocular pressure (IOP) can be impacted by a variety of ophthalmic conditions. Species-specific reference parameters from clinically normal animals are instrumental for understanding how ophthalmic diseases may impact ocular pressures. IOP measurements were obtained using rebound tonometry from free-ranging Peruvian fur seals ( unnamed subspecies) at Punta San Juan, Peru, over a 6-yr period (2010-2016).

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Case Description: A 9-year-old 37-kg sexually intact male snow leopard (Panthera uncia) with no history of lameness but radiographic evidence of right femoral subluxation and flattening of both femoral heads, 2 juvenile (< 1 year old) 25-kg sexually intact male cheetahs (Acinoynx jubatus) with unilateral hind limb lameness resulting from trauma, and an 11-year-old 110-kg sexually intact female Amur tiger (Panthera tigris altaica) with a 2-year history of left hip joint osteoarthritis were examined.

Clinical Findings: No clinically relevant clinical findings other than hip joint problems were identified. All 4 felids underwent staged bilateral (snow leopard) or unilateral (cheetahs and tiger [Panthera tigris]) total hip arthroplasty (THA).

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Adenoviruses are medium size nonenveloped viruses with a trend of coevolution with their hosts. We surveyed South American fur seals (Arctocephalus australis) and Humboldt penguins (Spheniscus humboldti) for adenoviruses at two sites from 2009 to 2012. Despite the common pattern of host specificity, some of the adenoviruses in our study were present in samples from unexpected host species.

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The spread of both infectious and noninfectious diseases through wildlife populations is of increasing concern. Neoplastic diseases are rarely associated with population-level impacts in wildlife; however, impacts on individual health can be severe and might reflect deteriorating environmental conditions. An adult male free-ranging Blanding's turtle () originally captured in 2005 and deemed healthy, was recaptured in 2018 with a 1 × 1.

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Systemic isosporosis (formerly atoxoplasmosis), is a protozoal infection that causes death in nestling and fledgling passerine birds impacting ex situ breeding and reintroduction programs. Because current antemortem diagnostic tests lack sensitivity, a qPCR was developed for detection of spp. using primers and a fluorescent-tagged MGB probe targeting the large subunit (28s) ribosomal RNA gene (assay efficiency = >100%; sensitivity = <1 dsDNA copy).

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Reproductive success of endangered Humboldt penguin (Spheniscus humboldti) colonies in Peru has been associated with nesting habitat type, presumably due to differences in environmental exposure and activity patterns that may affect energy demands and metabolism. Gas chromatography and mass spectrometry were used to determine serum concentrations of 19 saccharides from 30 Humboldt penguins nesting at Punta San Juan, Peru in order to evaluate differences in metabolic state between penguins nesting in a sheltered burrow or crevice (n = 17) and those in exposed surface nests (n = 13). Univariate and multivariate statistical analyses identified serum saccharides (arabinose, maltose, glucose-6-phosphate, and levoglucosenone in particular) that were nest-dimorphic with substantial differences between surface- and sheltered-nesting penguins.

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Free-ranging Humboldt penguin (HP, Spheniscus humboldti) populations are under pressure from resource competition with industrial fisheries, habitat loss, and El Niño Southern Oscillation events. Foraging patterns for this top marine predator change during periods of aberrant oceanographic conditions and scarce fish stock numbers. These radical dietary fluctuations can lead to poor fertility, early embryonic death, poor hatchability, suppressed immune function, high chick mortality, and illness.

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Assessment of pododermatitis, osteoarthritis, and other causes of lameness in penguins can be challenging. Subjective gait analysis using visual observation and response to analgesic therapy can be affected by observer variation and caregiver placebo bias. A pressure-sensitive walkway (PSW), however, allows for objective gait analysis and assessment of analgesic therapeutic response.

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This prospective study characterizes the impact of positioning on the pulmonary volume and pulmonary atelectasis in Egyptian fruit bats (). The soft tissue appearance of atelectactic pulmonary parenchyma can obscure or mask pulmonary pathology. Soft tissue within healthy lung parenchyma caused by atelectasis can efface the margins of pathology, such as pulmonary metastasis or pneumonia, due to overlapping attenuation profiles.

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Freshwater turtle species are suffering from anthropocentric-caused population declines, making preservation of professionally managed populations increasingly important. Turtles under professional care have an increased risk to develop hepatic lipidosis, potentially resulting in early death. Computed tomography can provide an antemortem screening for increased fatty liver composition.

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There are no studies to date on the normal reproductive physiology of African white-bellied pangolins (). As a reclusive species, little is known about normal gestation, successful parturition, and potential complications during pregnancy. Ten female were diagnosed as pregnant and monitored under professional care.

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Relatively little is known about pangolin care and physiology, and it has become increasingly important to have a better understanding of normal health parameters for evaluation of free-ranging, rehabilitating, and managed populations. Echocardiograms were performed on six African white-bellied pangolins () under professional care at a single institution. Because of the propensity of pangolins to roll up with only thick keratinized scales exposed, the pangolins were anesthetized with either isoflurane or sevoflurane.

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Synopsis of recent research by authors named "Michael J Adkesson"

  • - Recent research by Michael J Adkesson focuses on the health and disease prevalence in marine mammals and birds, particularly in relation to environmental toxins, viruses, and pharmacological treatments, emphasizing the health impacts of anthropogenic factors on these species.
  • - A significant study identified the prevalence of Otariid gammaherpesvirus 1 in South American fur seals and sea lions, revealing that 21% of samples tested positive for the virus, highlighting risks associated with age, sex, and sample type.
  • - Other notable investigations included assessing heavy metal exposure in Humboldt penguins’ eggs and the effects of SARS-CoV-2 in zoo animals, showcasing both the need for health monitoring in wildlife and the implications of zoonotic diseases in zoological settings.