• Amdoparvovirus Infection in Red Pandas (Ailurus fulgens)

      Alex, Charles E.; Kubiski, Steven V.; Li, Linlin; Sadeghi, Mohammadreza; Wack, Raymund F.; McCarthy, Megan A.; Pesavento, Joseph B.; Delwart, Eric; Pesavento, Patricia A. (2018)
      Aleutian mink disease virus is the type species in the genus Amdoparvovirus, and in mink and other Mustelidae can cause either subclinical disease or fatal chronic immune stimulation and immune complex disease. The authors describe a novel amdoparvovirus in the endangered red panda (Ailurus fulgens), discovered using viral metagenomics....
    • Cerebral Angiostrongylus cantonensis infection in a captive African pygmy falcon (Polihierax semitorquatus) in southern California

      Burns, Rachel E.; Bicknese, Elizabeth; Qvarnstrom, Yvonne; DeLeon-Carnes, Marlene; Drew, Clifton P.; Gardiner, Chris H.; Rideout, Bruce (2014)
      A 10-month-old, female African pygmy falcon (Polihierax semitorquatus) hatched and housed at the San Diego Zoo developed neurologic signs and died from a cerebral infection with the rat lungworm Angiostrongylus cantonensis…. To the authors’ knowledge, this infection has not previously been reported in a bird in the United States and has not been known to be naturally acquired in any species in this region of the world. The source of the infection was not definitively determined but was possibly feeder geckos (Hemidactylus frenatus) imported from Southeast Asia where the parasite is endemic.
    • Clinical challenge. Renal adenocarcinoma in a spitting cobra

      Belasco-Zeitz, Marianne; Pye, Geoffrey W.; Burns, Rachel E.; Pessier, Allan P. (2013)
      A 16-yr-old, male red spitting cobra (Naja pallida) (weight, 1.9 kg) presented with caudal coelomic swelling…. Blood from a male sibling (weight, 1.35 kg) was collected for comparison purposes and was reported with WBC < 5,000 × 106 cells/μl; uric acid, 6.4 mg/dl; calcium, 14.8 mg/dl; phosphorous, 6.6 mg/dl; total protein, 6.9 g/dl; and globulins, 4.2 g/dl…
    • Co-infection by alveolate parasites and frog virus 3-like ranavirus during an amphibian larval mortality event in Florida, USA

      Landsberg, J.H.; Kiryu, Y.; Tabuchi, M.; Preston, Asa; Pessier, Allan P. (2013)
      A multispecies amphibian larval mortality event, primarily affecting American bullfrogs Lithobates catesbeianus, was investigated during April 2011 at the Mike Roess Gold Head Branch State Park, Clay County, Florida, USA. Freshly dead and moribund tadpoles had hemorrhagic lesions around the vent and on the ventral body surface, with some exhibiting a swollen abdomen. Bullfrogs (100%), southern leopard frogs L. sphenocephalus (33.3%), and gopher frogs L. capito (100%) were infected by alveolate parasites. The intensity of infection in bullfrog livers was high. Tadpoles were evaluated for frog virus 3 (FV3) by histology and PCR. For those southern leopard frog tadpoles (n = 2) whose livers had not been obscured by alveolate spore infection, neither a pathologic response nor intracytoplasmic inclusions typically associated with clinical infections of FV3-like ranavirus were noted. Sequencing of a portion (496 bp) of the viral major capsid protein gene confirmed FV3-like virus in bullfrogs (n = 1, plus n = 6 pooled) and southern leopard frogs (n = 1, plus n = 4 pooled). In July 2011, young-of-the-year bullfrog tadpoles (n = 7) were negative for alveolate parasites, but 1 gopher frog tadpole was positive. To our knowledge, this is the first confirmed mortality event for amphibians in Florida associated with FV3-like virus, but the extent to which the virus played a primary role is uncertain. Larval mortality was most likely caused by a combination of alveolate parasite infections, FV3-like ranavirus, and undetermined etiological factors.
    • Comparative pathology of ranaviruses and diagnostic techniques

      Miller, D.L.; Pessier, Allan P.; Hick, P.; Whittington, R.J.; Gray M.; Chinchar V. (SpringerNew York, 2015)
      Recognizing the pathological changes caused by ranaviruses, understanding how to properly collect test samples, and knowing what diagnostic tools to choose are key to detecting ranaviruses and in determining whether they are a factor in morbidity and mortality events. Whether infection occurs in fish, reptiles, or amphibians, clinical disease is typically acute and can affect a high proportion of the population. Among ectothermic vertebrates, affected individuals can present with hemorrhages, edema, and necrosis. Generally, microscopic examination reveals intracytoplasmic inclusion bodies and necrosis of hematopoietic tissues, vascular endothelium, and epithelial cells. Ultimately, the type and severity of the lesions that develop vary depending upon the host species, type of ranavirus, or environmental factors. Our ability to identify lesions caused by ranaviruses is improving because of the knowledge gained from laboratory experiments and the improvement of existing, or development of new diagnostic tests. There is no single Gold Standard test for ranavirus detection, rather the diagnostic test chosen depends on the question asked. For example, a surveillance study may use quantitative real-time PCR (qPCR) to detect ranaviruses, but an investigation of a mortality event may use virus isolation, qPCR, histopathology, electron microscopy, and bioassay. To date, a treatment for ranavirus infections has not been found; however, vaccine development against iridoviruses is showing promise for both DNA and live vaccines within the aquaculture industry.
    • Congenital cleft palate and cardiac septal defects in a neonatal southern black rhinoceros (diceros bicornis minor)

      Lewis, Stephany; Duncan, Mary; Houck, Marlys L.; Bloch, Rebecca; Haefele, Holly (2016)
      A female Southern black rhinoceros (Diceros bicornis minor) calf died unexpectedly at less than 12 hr of age, after an uncomplicated birth and uneventful early postpartum period. Gross necropsy revealed a 15-cm full thickness cleft palate, a patent foramen ovale, and four septal defects ranging from 0.3 to 1 cm in diameter. Histologic findings did not reveal any significant abnormalities. Karyotyping did not indicate any significant numerical or structural chromosomal abnormalities.
    • Coupling gene-based and classic veterinary diagnostics improves interpretation of health and immune function in the Agassiz’s desert tortoise (Gopherus agassizii)

      Drake, K. Kristina; Bowen, Lizabeth; Lewison, Rebecca L.; Esque, Todd C.; Nussear, Kenneth E.; Braun, Josephine; Waters, Shannon C.; Miles, A. Keith (2017)
      The analysis of blood constituents is a widely used tool to aid in monitoring of animal health and disease. However, classic blood diagnostics (i.e. hematologic and plasma biochemical values) often do not provide sufficient information to determine the state of an animal’s health. Field studies on wild tortoises and other reptiles have had limited success in drawing significant inferences between blood diagnostics and physiological and immunological condition. However, recent research using gene transcription profiling in the threatened Mojave desert tortoise (Gopherus agassizii) has proved useful in identifying immune or physiologic responses and overall health. To improve our understanding of health and immune function in tortoises, we evaluated both standard blood diagnostic (body condition, hematologic, plasma biochemistry values, trace elements, plasma proteins, vitamin A levels) and gene transcription profiles in 21 adult tortoises (11 clinically abnormal; 10 clinically normal) from Clark County, NV, USA. Necropsy and histology evaluations from clinically abnormal tortoises revealed multiple physiological complications, with moderate to severe rhinitis or pneumonia being the primary cause of morbidity in all but one of the examined animals. Clinically abnormal tortoises had increased transcription for four genes (SOD, MyD88, CL and Lep), increased lymphocyte production, biochemical enzymes and organics, trace elements of copper, and decreased numbers of leukocytes. We found significant positive correlations between increased transcription for SOD and increased trace elements for copper, as well as genes MyD88 and Lep with increased inflammation and microbial insults. Improved methods for health assessments are an important element of monitoring tortoise population recovery and can support the development of more robust diagnostic measures for ill animals, or individuals directly impacted by disturbance.
    • Coupling gene-based and classic veterinary diagnostics improves interpretation of health and immune function in the Agassiz’s desert tortoise (Gopherus agassizii)

      Drake, K. Kristina; Bowen, Lizabeth; Lewison, Rebecca L.; Esque, Todd C.; Nussear, Kenneth E.; Braun, Josephine; Waters, Shannon C.; Miles, A. Keith (2017)
      The analysis of blood constituents is a widely used tool to aid in monitoring of animal health and disease. However, classic blood diagnostics (i.e. hematologic and plasma biochemical values) often do not provide sufficient information to determine the state of an animal’s health. Field studies on wild tortoises and other reptiles have had limited success in drawing significant inferences between blood diagnostics and physiological and immunological condition. However, recent research using gene transcription profiling in the threatened Mojave desert tortoise (Gopherus agassizii) has proved useful in identifying immune or physiologic responses and overall health. To improve our understanding of health and immune function in tortoises, we evaluated both standard blood diagnostic (body condition, hematologic, plasma biochemistry values, trace elements, plasma proteins, vitamin A levels) and gene transcription profiles in 21 adult tortoises (11 clinically abnormal; 10 clinically normal) from Clark County, NV, USA. Necropsy and histology evaluations from clinically abnormal tortoises revealed multiple physiological complications, with moderate to severe rhinitis or pneumonia being the primary cause of morbidity in all but one of the examined animals. Clinically abnormal tortoises had increased transcription for four genes (SOD, MyD88, CL and Lep), increased lymphocyte production, biochemical enzymes and organics, trace elements of copper, and decreased numbers of leukocytes. We found significant positive correlations between increased transcription for SOD and increased trace elements for copper, as well as genes MyD88 and Lep with increased inflammation and microbial insults. Improved methods for health assessments are an important element of monitoring tortoise population recovery and can support the development of more robust diagnostic measures for ill animals, or individuals directly impacted by disturbance.
    • Development of a case definition for clinical feline herpesvirus infection in cheetahs (acinonyx jubatus) housed in zoos

      Witte, Carmel L.; Lamberski, Nadine; Rideout, Bruce; Fields, Victoria; Teare, Cyd Shields; Barrie, Michael; Haefele, Holly; Junge, Randall; Murray, Suzan; Hungerford, Laura L. (2013)
      The identification of feline herpesvirus (FHV) infected cheetahs (Acinonyx jubatus) and characterization of shedding episodes is difficult due to nonspecific clinical signs and limitations of diagnostic tests. The goals of this study were to develop a case definition for clinical FHV and describe the distribution of signs. Medical records from six different zoologic institutions were reviewed to identify cheetahs with diagnostic test results confirming FHV….
    • Efficacy of treatment and long-term follow-up of Batrachochytrium dendrobatidis PCR-positive anurans following itraconazole bath treatment

      Georoff, Timothy A.; Moore, Robert P.; Rodriguez, Carlos; Pessier, Allan P.; Newton, Alisa L.; McAloose, Denise; Calle, Paul P. (2013)
      All anuran specimens in the Wildlife Conservation Society's collections testing positive for Batrachochytrium dendrobatidis (Bd) were treated with itraconazole and then studied after treatment to assess the long-term effects of itraconazole and the drug's effectiveness in eliminating Bd carriers. Twenty-four individuals and eight colonies of 11 different species (75 total specimens) tested positive for Bd via polymerase chain reaction (PCR) on multicollection survey. All positive individuals and colonies were treated with a 0.01% itraconazole bath solution and retested for Bd via one of two PCR methodologies within 14 days of treatment completion, and all were negative for Bd. A total of 64 animals received secondary follow-up PCR testing at the time of death, 6–8 mo, or 12–15 mo post-treatment. Fourteen animals (14/64, 21.9%) were PCR positive for Bd on second follow-up. The highest percentage positive at second recheck were green-and-black poison dart frogs (Dendrobates auratus; 5/5 specimens, 100%), followed by red-eyed tree frogs (Agalychnis callidryas; 4/11, 36.4%), grey tree frogs (Hyla versicolor; 1/3, 33.3%), and green tree frogs (Hyla cinera; 3/11, 27.3%). Re-testing by PCR performed on 26/28 individuals that died during the study indicated 11/26 (42.3%) were positive (all via DNA extracted from formalin-fixed paraffin-embedded skin sections). However, there was no histologic evidence of chytridiomycosis in any of 27/28 individuals. The small number of deceased animals and effects of postmortem autolysis limited the ability to determine statistical trends in the pathology data, but none of the necropsied specimens showed evidence of itraconazole toxicity. Problems with itraconazole may be species dependent, and this report expands the list of species that can tolerate treatment. Although itraconazole is effective for clearance of most individuals infected with Bd, results of the study suggest that repeat itraconazole treatment and follow-up diagnostics may be required to ensure that subclinical infections are eliminated in amphibian collections.
    • Elaeophora in the meninges of a Malayan sambar (Rusa unicolor equina)

      Bernard, Jennifer; Grunenwald, Caroline; Stalis, Ilse H.; Varney, Megan; Zuba, Jeffery R.; Gerhold, Richard (2016)
      An adult nematode was grossly identified in the meninges of a Malayan sambar (Rusa unicolor equina), with numerous microfilariae associated with encephalitis and vasculitis on histopathology. The nematode was confirmed to be Elaeophora schneideri by sequencing a portion of the 18S rRNA gene. Our report highlights the potential for aberrant migration of E. schneideri in exotic deer species and the use of advanced testing to specifically identify this metazoan parasite, avoiding misidentification of Parelaphostrongylus tenuis.
    • Hepatitis and splenitis due to systemic tetratrichomoniasis in an American white pelican (Pelecanus erythrorhynchos)

      Burns, Rachel E.; Braun, Josephine; Armién, Aníbal G.; Rideout, Bruce (2013)
      A free-ranging, young adult, female American white pelican (Pelecanus erythrorhynchos), found dead on the grounds of the San Diego Zoo Safari Park in Southern California, had severe multifocal to coalescing necrotizing hepatitis and splenitis on postmortem examination. Histologically, within the large areas of necrosis were myriad pleomorphic, 5–20 µm in diameter, protozoal organisms with 1 to multiple nuclei. Ultrastructurally, the organisms were consistent with a trichomonad flagellate. Polymerase chain reaction and sequencing of the small subunit ribosomal RNA gene identified nucleotide sequences with 99% identity to Tetratrichomonas gallinarum, which is a common inhabitant of the intestinal tract of galliform and anseriform birds that has occasionally been associated with disease, including typhlitis and hepatitis. Damage to the cecal mucosa in the pelican from trematodes and secondary bacterial infection could have allowed invasion and systemic dissemination of the organism. Exposure of the pelican to a variety of native and exotic anseriform and galliform birds at the zoological institution could have led to cross-species infection and severe manifestation of disease in a novel host.
    • Laboratory diagnostics

      Rideout, Bruce; Braun, Josephine; Pessier, Allan P.; Terio, Karen A.; McAloose, Denise; St. Leger, Judy (Academic PressSan Diego, CA, 2018)
      This chapter focuses on the challenges of using laboratory diagnostics in wildlife and how to choose an appropriate test and interpret the results. Very few diagnostic tests have been validated for use in wildlife, which creates challenges for the diagnostician because some of these tests must be used anyway, while others should be avoided....
    • Molecular methods to detect Mycoplasma spp. and testudinid herpesvirus 2 in desert tortoises (Gopherus agassizii) and implications for disease management

      Braun, Josephine; Schrenzel, Mark D.; Witte, Carmel L.; Gokool, Larisa; Burchell, Jennifer; Rideout, Bruce (2014)
      Mycoplasmas are an important cause of upper respiratory tract disease (URTD) in desert tortoises (Gopherus agassizii) and have been a main focus in attempts to mitigate disease-based population declines. Infection risk can vary with an animal's population of origin, making screening tests popular tools for determining infection status in individuals and populations…. Our findings suggest that mycoplasmas are not the only agents of concern and that a single M. agassizii ELISA or nasal flush qPCR alone failed to identify all potentially infected animals in a population….
    • Pathogenesis, diagnosis, and treatment of amphibian chytridiomycosis

      Baitchman, Eric J.; Pessier, Allan P. (2013)
      Amphibian chytridiomycosis, caused by the chytridiomycete fungus, Batrachochytrium dendrobatidis (Bd), is responsible for a global pandemic that has dramatically reduced global amphibian populations and diversity. Species declines, extirpations, and extinctions attributed to chytridiomycosis have occurred in Australia, Europe, Latin America, and the United States….
    • Pulmonary hyalinosis in captive sugar gliders (Petaurus breviceps)

      Sokol, Set A.; Agnew, Dalen W.; Lewis, Anne D.; Southard, Teresa L.; Miller, Andrew D. (2017)
      ...Lung lesions resembling pulmonary hyalinosis were observed in 6 captive adult sugar gliders (Petaurus breviceps; 5 females and 1 male) in a retrospective review of 18 autopsied animals. Clinical signs for 3 of the sugar gliders included lethargy, tachypnea, and dyspnea....
    • Rapid response to evaluate the presence of amphibian chytrid fungus (Batrachochytrium dendrobatidis) and ranavirus in wild amphibian populations in Madagascar

      Kolby, Jonathan E.; Smith, Kristine M.; Ramirez, Sara D.; Rabemananjara, Falitiana; Pessier, Allan P.; Brunner, Jesse L.; Goldberg, Caren S.; Berger, Lee; Skerratt, Lee F. (2015)
      We performed a rapid response investigation to evaluate the presence and distribution of amphibian pathogens in Madagascar following our identification of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) and ranavirus in commercially exported amphibians. This targeted risk-based field surveillance program was conducted from February to April 2014 encompassing 12 regions and 47 survey sites. We simultaneously collected amphibian and environmental samples to increase survey sensitivity and performed sampling both in wilderness areas and commercial amphibian trade facilities. Bd was not detected in any of 508 amphibian skin swabs or 68 water filter samples, suggesting pathogen prevalence was below 0.8%, with 95% confidence during our visit. Ranavirus was detected in 5 of 97 amphibians, including one adult Mantidactylus cowanii and three unidentified larvae from Ranomafana National Park, and one adult Mantidactylus mocquardi from Ankaratra. Ranavirus was also detected in water samples collected from two commercial amphibian export facilities. We also provide the first report of an amphibian mass-mortality event observed in wild amphibians in Madagascar. Although neither Bd nor ranavirus appeared widespread in Madagascar during this investigation, additional health surveys are required to disentangle potential seasonal variations in pathogen abundance and detectability from actual changes in pathogen distribution and rates of spread. Accordingly, our results should be conservatively interpreted until a comparable survey effort during winter months has been performed. It is imperative that biosecurity practices be immediately adopted to limit the unintentional increased spread of disease through the movement of contaminated equipment or direct disposal of contaminated material from wildlife trade facilities. The presence of potentially introduced strains of ranaviruses suggests that Madagascar's reptile species might also be threatened by disease. Standardized population monitoring of key amphibian and reptile species should be established with urgency to enable early detection of potential impacts of disease emergence in this global biodiversity hotspot.
    • Resolution of a localized granuloma caused by Mycobacterium avium-intracellulare complex on the cere of a Bruce's green pigeon (Treron waalia)

      Zikovitz, Andrea E.; Stalis, Ilse H.; Bicknese, Elizabeth; Rideout, Bruce; Pye, Geoffrey W. (2018)
      A 3-year-old female Bruce's green pigeon (Treron waalia) was presented with granulomatous inflammation of the cere and underlying tissues with osteomyelitis and bone proliferation of the dorsal premaxilla. Biopsy and culture revealed the presence of Mycobacterium avium-intracellulare complex, and multi-antimicrobial treatment was initiated with clarithromycin, ethambutol, rifabutin, and enrofloxacin....
    • Survey of Plasmodium spp. in free-ranging neotropical primates from the Brazilian Amazon region impacted by anthropogenic actions

      Bueno, Marina G.; Rohe, Fabio; Kirchgatter, Karin; Di Santi, Silvia M. F.; Guimarães, Lilian O.; Witte, Carmel L.; Costa-Nascimento, Maria J.; Toniolo, Christina R. C.; Catão-Dias, José Luiz (2013)
      This study investigated Plasmodium spp. infection in free-ranging neotropical primates from Brazilian Amazon regions under the impact of major anthropogenic actions. Blood samples from 19 new world primates were collected and analyzed with microscopic and molecular procedures. The prevalence of Plasmodium infection was 21.0% (4/19) and PCR positive samples were identified as P. brasilianum. Considering the social-economic changes that the Amazon is facing, the prevalence of P. brasilianum infection highlights the necessity to closely monitor the movement of both human and non-human primate populations, in order to mitigate pathogen exposure and the introduction of new agents into previously naïve areas.