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Full-Text Articles in Life Sciences

Frequent Cross-Species Transmission Of Parvoviruses Among Diverse Carnivore Hosts, Andrew Allison, Dennis Kohler, Karen Fox, Justin Brown, Richard Gerhold, Valerie Shearn-Bochsler, Edward Dubovi, Colin Parrish, Edward Holmes Jan 2013

Frequent Cross-Species Transmission Of Parvoviruses Among Diverse Carnivore Hosts, Andrew Allison, Dennis Kohler, Karen Fox, Justin Brown, Richard Gerhold, Valerie Shearn-Bochsler, Edward Dubovi, Colin Parrish, Edward Holmes

Richard W. Gerhold Jr., DVM, MS, PhD

Although parvoviruses are commonly described in domestic carnivores, little is known about their biodiversity in nondomestic species. A phylogenetic analysis of VP2 gene sequences from puma, coyote, gray wolf, bobcat, raccoon, and striped skunk revealed two major groups related to either feline panleukopenia virus ("FPV-like") or canine parvovirus ("CPV-like"). Cross-species transmission was commonplace, with multiple introductions into each host species but, with the exception of raccoons, relatively little evidence for onward transmission in nondomestic species.


Molecular Confirmation Of Trichomonas Gallinae And Other Parabasalids From Brazil Using The 5.8s And Its-1 Rrna Regions, R Ecco, I Preis, D Vilela, M Luppi, M Malta, R Beckstead, R Stimmelmayer, Richard Gerhold Jr. Nov 2012

Molecular Confirmation Of Trichomonas Gallinae And Other Parabasalids From Brazil Using The 5.8s And Its-1 Rrna Regions, R Ecco, I Preis, D Vilela, M Luppi, M Malta, R Beckstead, R Stimmelmayer, Richard Gerhold Jr.

Richard W. Gerhold Jr., DVM, MS, PhD

Clinical, gross, and histopathology lesions and molecular characterization of Trichomonas spp. infection were described in two striped owls (Asio (Rhinoptynx) clamator), one American kestrel (Falco sparverius), two green-winged saltators (Saltator similis), and in a toco toucan (Ramphastos toco) from Brazil. These birds presented clinical signs including emaciation, ruffled feathers, abundant salivation and open mouth breathing presumably due to abundant caseous material. Gross lesions were characterized by multifocal yellow friable plaques on the surface of the tongue, pharynx and/or caseous masses partially occluding the laryngeal entrance. In the owls, the caseous material extended into the mandibular muscles and invaded the ...


Trichomonosis In Free-Ranging Eurasian Collared Doves (Streptopelia Decaocto) And African Collared Dove Hybrids (Streptopelia Risoria) In The Caribbean And Description Of Its-1 Region Genotypes, R Stimmelmayr, L Stefani, M Thrall, K Landers, F Revan, A Miller, R Beckstead, Richard Gerhold Jr. May 2012

Trichomonosis In Free-Ranging Eurasian Collared Doves (Streptopelia Decaocto) And African Collared Dove Hybrids (Streptopelia Risoria) In The Caribbean And Description Of Its-1 Region Genotypes, R Stimmelmayr, L Stefani, M Thrall, K Landers, F Revan, A Miller, R Beckstead, Richard Gerhold Jr.

Richard W. Gerhold Jr., DVM, MS, PhD

We report the first documented occurrence of an outbreak of trichomonosis in a free-ranging small flock of Eurasian collared doves (Streptopelia decaocto) and African collared dove hybrids (Streptopelia risoria) in the Caribbean. In total, 18 birds were examined, including six African collared dove x Eurasian collared dove hybrids and 12 Eurasian collared doves. The affected age class consisted of adults. Sex distribution was equal. With a flock population size of 200 birds, mortality rate for the outbreak was estimated at 15-20%. Living birds were weak, showing evidence of mucus-stained beaks and open-mouth breathing. Caseous ulcerative yellow lesions were restricted to ...


Widespread Occurrence Of Ranavirus In Pond-Breeding Amphibian Populations., J. Hoverman, Matthew Gray, Debra Miller, Nathan Haislip Dec 2011

Widespread Occurrence Of Ranavirus In Pond-Breeding Amphibian Populations., J. Hoverman, Matthew Gray, Debra Miller, Nathan Haislip

Debra L Miller

Ranaviruses are an emerging threat for many amphibian populations, yet their distribution in amphibian communities and the association of infection with possible stressors and species is not fully understood due to historically sparse surveillance. Agricultural practices that reduce the water quality of amphibian breeding habitats (e.g., cattle access to wetlands) and environmental stressors (e.g., lower temperatures) may contribute to ranavirus emergence. We tested larval amphibians for ranavirus infection across four seasons in farm ponds ( n=40) located in Tennessee, USA. Cattle at various densities were allowed access to half of the sampled ponds. Ranavirus infections were detected in ...


Maternal Health Status Correlates With Nest Success Of Leatherback Sea Turtles (Dermochelys Coriacea) From Florida, J. Perrault, Debra Miller, E. Eads, C. Johnson, A. Merrill, L. Thompson, J. Wynekenmaternal Health Status Correlates With Nest Success Of Leatherback Sea Turtles (Dermochelys Coriacea) From Florida Dec 2011

Maternal Health Status Correlates With Nest Success Of Leatherback Sea Turtles (Dermochelys Coriacea) From Florida, J. Perrault, Debra Miller, E. Eads, C. Johnson, A. Merrill, L. Thompson, J. Wynekenmaternal Health Status Correlates With Nest Success Of Leatherback Sea Turtles (Dermochelys Coriacea) From Florida

Debra L Miller

Of the seven sea turtle species, the critically endangered leatherback sea turtle (Dermochelys coriacea) exhibits the lowest and most variable nest success (i.e., hatching success and emergence success) for reasons that remain largely unknown. In an attempt to identify or rule out causes of low reproductive success in this species, we established the largest sample size (n = 60–70 for most values) of baseline blood parameters (protein electrophoresis, hematology, plasma biochemistry) for this species to date. Hematologic, protein electrophoretic and biochemical values are important tools that can provide information regarding the physiological condition of an individual and population health ...


Reliability Of Non-Lethal Surveillance Methods For Detecting Ranavirus Infection, Matthew Gray, Debra Miller, J. Hoverman Dec 2011

Reliability Of Non-Lethal Surveillance Methods For Detecting Ranavirus Infection, Matthew Gray, Debra Miller, J. Hoverman

Debra L Miller

Ranaviruses have been identified as the etiologic agent in many amphibian die-offs across the globe. Polymerase chain reaction (PCR) is commonly used to detect ranavirus infection in amphibian hosts, but the test results may vary between tissue samples obtained by lethal and non-lethal procedures. Testing liver samples for infection is a common lethal sampling technique to estimate ranavirus prevalence because the pathogen often targets this organ and the liver is easy to identify and collect. However, tail clips or swabs may be more practicable for ranavirus surveillance programs compared with collecting and euthanizing animals, especially for uncommon species. Using PCR ...


Natural Stressors And Disease Risk: Does The Threat Of Predation Increase Amphibian Susceptibility To Ranavirus?, Nathan Haislip, J. Hoverman, Debra Miller, Matthew Gray Dec 2011

Natural Stressors And Disease Risk: Does The Threat Of Predation Increase Amphibian Susceptibility To Ranavirus?, Nathan Haislip, J. Hoverman, Debra Miller, Matthew Gray

Debra L Miller

Emerging infectious diseases have been identified as threats to biodiversity, yet our understanding of the factors contributing to host susceptibility to pathogens within natural populations remains limited. It has been proposed that species interactions within communities affect host susceptibility to pathogens, thereby contributing to disease emergence. In particular, predation risk is a common natural stressor that has been hypothesized to compromise immune function of prey through chronic stress responses possibly leading to increased susceptibility to pathogens. We examined whether predation risk experienced during the development of four larval anuran species increases susceptibility (mortality and infection) to ranaviruses, a group of ...


Reports Of Oligodendrogliomas In Three White-Tailed Deer (Odocoileus Virginianus), N Gottdenker, Richard Gerhold Jr., A Cartoceti, M Keel, J Goltz, E Howerth Dec 2011

Reports Of Oligodendrogliomas In Three White-Tailed Deer (Odocoileus Virginianus), N Gottdenker, Richard Gerhold Jr., A Cartoceti, M Keel, J Goltz, E Howerth

Richard W. Gerhold Jr., DVM, MS, PhD

Central nervous system tumors are rarely reported in cervids. The current report describes gross and histopathologic oligodendrogliomas in 3 white-tailed deer (Odocoileus virginianus), and selected immunohistochemical properties of 2 deer. All deer were euthanized due to central nervous system signs. Grossly, masses were variably circumscribed, locally invasive in the brain, light grey, and soft, and ranged from 2 to 5 cm in diameter. Histologically, tumors were characteristic for oligodendroglioma. The tumors were composed primarily of oval to round cells with round normochromatic to hyperchromatic nuclei, a pale granular cytoplasm, and well-delineated cytoplasmic membrane, and variable amounts of mucinous material, hemorrhage ...


Diagnosis Of Parelaphostrongylus Spp. Infection As A Cause Of Meningomyelitis In Calves, K Mitchell, J Peters-Kennedy, T Stokol, Richard Gerhold Jr., R Beckstead, T Divers Oct 2011

Diagnosis Of Parelaphostrongylus Spp. Infection As A Cause Of Meningomyelitis In Calves, K Mitchell, J Peters-Kennedy, T Stokol, Richard Gerhold Jr., R Beckstead, T Divers

Richard W. Gerhold Jr., DVM, MS, PhD

Migration of Parelaphostrongylus spp. has been documented to cause central nervous system damage in a number of aberrant host species but appears to be uncommon in cattle. The current report describes the clinical and laboratory findings, antemortem and definitive diagnosis, and response to treatment of Parelaphostrongylus spp. infection in five 3-7- month-old Limousin calves from 2 farms. All calves had signs of acute (n = 2) and chronic (n = 3) progressive spinal cord dysfunction. Cerebrospinal fluid analysis revealed a marked eosinophilic (acute cases) or lymphocytic (chronic cases) pleocytosis and elevated protein in all calves. A necropsy and histopathologic evaluation was performed ...


Construction Of Pcr Primers To Detect And Distinguish Eimeria Spp. In Northern Bobwhites And A Survey Of Eimeria On Gamebird Farms In The United States, Richard Gerhold Jr., L Mcdougald, R Beckstead Sep 2011

Construction Of Pcr Primers To Detect And Distinguish Eimeria Spp. In Northern Bobwhites And A Survey Of Eimeria On Gamebird Farms In The United States, Richard Gerhold Jr., L Mcdougald, R Beckstead

Richard W. Gerhold Jr., DVM, MS, PhD

Coccidiosis is an important disease in captive gamebirds, including northern bobwhites (Colinusvirginianus). Three Eimeria species, Eimeria lettyae, Eimeria dispersa, and Eimeria colini, have been described in bobwhites. Distinguishing the various Eimeria spp. is often problematic because of similarity in oocyst morphology and site of infection and thus requires live bird infections to distinguish between the coccidian species. To aid in identification and diagnosis, PCR specific primers were generated against the internal transcribed spacer region 1 (ITS-1) of the ribosomal RNA gene using sequences obtained from coccidian-positive samples collected from diagnostic cases or litter from captive bobwhites. Three distinct Eimeria spp ...


Immunization Of Chukar Partridges Against Coccidia (Eimeria Kofoidi And Eimeria Legionensis) With Low Doses Of Live Oocysts, A Fuller, Richard Gerhold Jr., L Mcdougald Aug 2011

Immunization Of Chukar Partridges Against Coccidia (Eimeria Kofoidi And Eimeria Legionensis) With Low Doses Of Live Oocysts, A Fuller, Richard Gerhold Jr., L Mcdougald

Richard W. Gerhold Jr., DVM, MS, PhD

Experiments were conducted to determine whether chukar partridge (Alectoris chukar) chicks would develop protective immunity after inoculation with coccidia. Young chukar chicks in battery cages inoculated with 100 or more oocysts of Eimeria kofoidi or Eimeria legionensis had significant protection at challenge 4 wk later, as measured by greatly reduced oocyst shedding and improved weight gain as compared with unvaccinated, challenged controls. However, when birds were housed in litter pens and vaccinated by various regimens (including two species of chukar coccidia at 100/dose), coccidiosis rapidly spread through all treatments and caused significant mortality. Vaccination with Coccivac-T or with 100 ...


Molecular Characterization Of Histomonas Meleagridis And Other Parabasalids In The United States Using The 5.8s, Its-1, And Its-2 Rrna Regions, L Lollis, Richard Gerhold Jr., L Mcdougald, R Beckstead Jul 2011

Molecular Characterization Of Histomonas Meleagridis And Other Parabasalids In The United States Using The 5.8s, Its-1, And Its-2 Rrna Regions, L Lollis, Richard Gerhold Jr., L Mcdougald, R Beckstead

Richard W. Gerhold Jr., DVM, MS, PhD

Extracted DNA from 28 Histomonas meleagridis -infected avian tissue samples from multiple hosts and geographic locations was analyzed for variation in the 5.8S rRNA and the flanking internal transcribed spacer regions (ITS 1 and ITS 2). Samples were amplified by polymerase chain reaction, sequenced, and compared with known sequences from GenBank accessions of H. meleagridis and other related protozoa. The analyses revealed significant genetic variation within H. meleagridis sequences and suggested the possibility of multiple genotypes within the samples or a possible misdiagnosis. Related protozoa found in some samples were mostly identified as Tetratrichomonas spp. However, 1 sample had ...


Alternaria Fungal Dermatitis In A Free-Ranging Javelina (Pecari Tajacu), L Shender, Richard Gerhold Jr., S Sanchez, M Keel Jun 2011

Alternaria Fungal Dermatitis In A Free-Ranging Javelina (Pecari Tajacu), L Shender, Richard Gerhold Jr., S Sanchez, M Keel

Richard W. Gerhold Jr., DVM, MS, PhD

We report a javelina from Pinal County, Arizona, USA, with severe fungal dermatitis and cellulitis. Extreme emaciation and rostral disfiguration, including left-lateral displacement of the nasal planum, justified euthanasia. A pus-filled tract within the rostrum was observed. Histopathology revealed granulomatous inflammation with hyphae morphologically consistent with Alternaria sp. isolated by culture.


Oocyst Production Of Eimeria Lettyae In Northern Bobwhites Following Low-Dose Inoculations, Richard Gerhold Jr., E Guven, L Mcdougald May 2011

Oocyst Production Of Eimeria Lettyae In Northern Bobwhites Following Low-Dose Inoculations, Richard Gerhold Jr., E Guven, L Mcdougald

Richard W. Gerhold Jr., DVM, MS, PhD

Inoculation of northern bobwhite quail ( Colinus virginianus ) with low doses of Eimeria lettyae oocysts stimulates a protective immune response, suggesting immunization may be an option for controlling coccidiosis. However, the oocyst production of inoculated birds could be considerable, leading to subsequent outbreaks. To determine the oocyst production following inoculation with E. lettyae, we orally infected 12-wk-old bobwhites with 100, 1,000, or 10,000 sporulated oocysts. Fecal materials were collected on days 5-9 post-inoculation, and total oocyst production was counted in McMaster chambers. Oocyst production/bird was 49.75, 89.5, and 436 × 10(6) for 100, 1,000, or ...


Prevalence To Toxoplasma Gondii And Sarcocystis Spp. In A Reintroduced Fisher (Martes Pennanti) Population In Pennsylvania, J Larkin, M Gabriel, Richard Gerhold Jr., M Yabsley, J Wester, J Humphreys, R Beckstead, J Dubey May 2011

Prevalence To Toxoplasma Gondii And Sarcocystis Spp. In A Reintroduced Fisher (Martes Pennanti) Population In Pennsylvania, J Larkin, M Gabriel, Richard Gerhold Jr., M Yabsley, J Wester, J Humphreys, R Beckstead, J Dubey

Richard W. Gerhold Jr., DVM, MS, PhD

Understanding the role of disease in population regulation is important to the conservation of wildlife. We evaluated the prevalence of Toxoplasma gondii exposure and Sarcocystis spp. infection in 46 road-killed and accidentally trapper-killed fisher (Martes pennanti) carcasses collected and stored at -20 C by the Pennsylvania Game Commission from February 2002 to October 2008. Blood samples were assayed for T. gondii antibodies using the modified agglutination test (MAT, 1 : 25) and an indirect immunofluorescent antibody test (IFAT, 1 : 128). For genetic analysis, DNA samples were extracted from thoracic and pelvic limb skeletal muscle from each carcass to test for Sarcocystis ...


Partial Sequence Of The Alpha-Tubulin Gene From Histomonas Meleagridis Isolates From The United States, Richard Gerhold Jr., L Lollis, L Mcdougald, R Beckstead Mar 2011

Partial Sequence Of The Alpha-Tubulin Gene From Histomonas Meleagridis Isolates From The United States, Richard Gerhold Jr., L Lollis, L Mcdougald, R Beckstead

Richard W. Gerhold Jr., DVM, MS, PhD

Histomonas meleagridis , the causative agent of histomoniasis, is a protozoan parasite classified in the Dientamoebidae (order Tritrichomonadida). The α-tubulin gene of 7 H. meleagridis isolates originating from either domestic chickens or turkeys from the United States was amplified by nested PCR and sequenced. A 91.4-99.8% nucleotide identity was shared among the 7 different sequences, and phylogenetic analysis disclosed that the 7 isolates were divided into at least 3 clades. These sequences had a 91-99% nucleotide identity and a 96-100% amino acid identity compared with 3 H. meleagridis α-tubulin sequences obtained from isolates originating from turkeys in Germany. Further ...


The Efficacy Of Anticoccidial Products Against Eimeria Spp. In Northern Bobwhites, Richard Gerhold Jr., A Fuller, L Lollis, C Parr, L Mcdougald Feb 2011

The Efficacy Of Anticoccidial Products Against Eimeria Spp. In Northern Bobwhites, Richard Gerhold Jr., A Fuller, L Lollis, C Parr, L Mcdougald

Richard W. Gerhold Jr., DVM, MS, PhD

To determine whether chemotherapeutic compounds available for use in domestic poultry are effective at controlling coccidiosis in northern bobwhites (Colinus virginianus), we tested 13 chemotherapeutic anticoccidials including amprolium (250 parts per million [ppm]), clopidol (125 ppm), diclazuril (1 ppm and 2 ppm), decoquinate (30 ppm), lasalocid (120 ppm), monensin (90 ppm), narasin/nicarbazin (36/36 ppm), robenidine (33 ppm), roxarsone (50 ppm), sulfadimethoxine/ ormetoprin (125/75 ppm), salinomycin (60 ppm), semduramicin (25 ppm), and zoalene (125 ppm and 150 ppm). Three tests were conducted using two replicates of 10 birds each: Infected, unmedicated controls and medicated birds were challenged with ...


Ranavirus: Past, Present And Future., D. Lesbarrères, A. Balseiro, J. Brunner, V. Chinchar, A. Duffus, J. Kirby, Debra Miller, J. Robert, D. Schock, T. Waltzek, Matthew Gray Dec 2010

Ranavirus: Past, Present And Future., D. Lesbarrères, A. Balseiro, J. Brunner, V. Chinchar, A. Duffus, J. Kirby, Debra Miller, J. Robert, D. Schock, T. Waltzek, Matthew Gray

Debra L Miller

Emerging infectious diseases are a significant threat to global biodiversity. While historically overlooked, a group of iridoviruses in the genus Ranavirus has been responsible for die-offs in captive and wild amphibian, reptile and fish populations around the globe over the past two decades. In order to share contemporary information on ranaviruses and identify critical research directions, the First International Symposium on Ranaviruses was held in July 2011 in Minneapolis, MN, USA. Twenty-three scientists and veterinarians from nine countries examined the ecology and evolution of ranavirus-host interactions, potential reservoirs, transmission dynamics, as well as immunological and histopathological responses to infection. In ...


Development And Disease: How Susceptibility To An Emerging Pathogen Changes Through Anuran Development., N. Haislip, Matthew Gray, J. Hoverman, Debra Miller Dec 2010

Development And Disease: How Susceptibility To An Emerging Pathogen Changes Through Anuran Development., N. Haislip, Matthew Gray, J. Hoverman, Debra Miller

Debra L Miller

Ranaviruses have caused die-offs of amphibians across the globe. In North America, these pathogens cause more amphibian mortality events than any other pathogen. Field observations suggest that ranavirus epizootics in amphibian communities are common during metamorphosis, presumably due to changes in immune function. However, few controlled studies have compared the relative susceptibility of amphibians to ranaviruses across life stages. Our objectives were to measure differences in mortality and infection prevalence following exposure to ranavirus at four developmental stages and determine whether the differences were consistent among seven anuran species. Based on previous studies, we hypothesized that susceptibility to ranavirus would ...


Why Are Hatching And Emergence Success Low? Mercury And Selenium Concentrations In Nesting Leatherback Sea Turtles (Dermochelys Coriacea) And Their Young In Florida., J. Perrault, J. Wyneken, L. Thompson, C. Johnson, Debra Miller Dec 2010

Why Are Hatching And Emergence Success Low? Mercury And Selenium Concentrations In Nesting Leatherback Sea Turtles (Dermochelys Coriacea) And Their Young In Florida., J. Perrault, J. Wyneken, L. Thompson, C. Johnson, Debra Miller

Debra L Miller

Leatherback sea turtles (Dermochelys coriacea) have low hatching and emergence success compared to other sea turtle species. Postmortem examinations of hatchlings showed degeneration of heart and skeletal muscle that was similar to that found in other neonates with selenium deficient mothers. Selenium deficiency can result from elevated concentrations of bodily mercury. Ingested mercury is detoxified by the liver through mercury-selenium compound formation. In animals persistently exposed to mercury, the liver's ability to detoxify this element may decrease, especially if dietary selenium is insufficient. We measured mercury and selenium concentrations in nesting female leatherbacks and their hatchlings from Florida and ...


2011 International Ranavirus Symposium, R. Marschang, Debra Miller Dec 2010

2011 International Ranavirus Symposium, R. Marschang, Debra Miller

Debra L Miller

This article summarizes the state of Ranavirus knowledge, ongoing research, and future activities. Ranaviruses are large dsDNA viruses in the family Iridoviridae. They were originally detected in frogs (hence the name of the genus, Ranavirus) but are now known to infect and cause disease in fish and reptiles as well as in amphibians. Ranaviruses have been associated with numerous die-offs in amphibian populations and have also been increasingly found in fish and reptiles in recent years. Their role in amphibian declines and as emerging pathogens has led to increased awareness of the importance of these pathogens in conservation and ectothermic ...


Histological Findings In Free-Ranging Sarasota Bay Bottlenose Dolphin (Tursiops Truncatus) Skin: Mercury, Selenium, And Seasonal Factors., Debra Miller, V. Woshner, E. Styer, S. Ferguson, K. Knott, Matthew Gray, R. Wells, T. O'Hara Dec 2010

Histological Findings In Free-Ranging Sarasota Bay Bottlenose Dolphin (Tursiops Truncatus) Skin: Mercury, Selenium, And Seasonal Factors., Debra Miller, V. Woshner, E. Styer, S. Ferguson, K. Knott, Matthew Gray, R. Wells, T. O'Hara

Debra L Miller

Full-thickness epidermal biopsy samples were collected from free-ranging common bottlenose dolphins (Tursiops truncatus) in Sarasota Bay, Florida, USA. Season (summer or winter) of collection, mercury (Hg) concentration, and selenium (Se) concentration were compared to histologic parameters. Epidermal Hg concentration was positively related to age (P<0.001) and negatively related to height of the stratum spinosum (P<0.05). The mitotic index and heights of the stratum externum and intermedium were lower in summer than in winter (P<0.01). Transmission electron microscopic examination revealed variation in the diameters (60–138 nm) and arrangements of collagen fibers, regardless of age ...


Intersex Condition Of Shoal Bass In The Flint River, Georgia., D. Ingram, Debra Miller, T. Ingram, J. Tannehill Dec 2010

Intersex Condition Of Shoal Bass In The Flint River, Georgia., D. Ingram, Debra Miller, T. Ingram, J. Tannehill

Debra L Miller

We examined male shoal bass Micropterus cataractae from the Flint River, Georgia, to determine the prevalence of intersex. During March and April 2010, we sampled 61 shoal bass from six sites along the Flint River. Testes were examined histologically and classified as intersex if the presence of oocytes was noted. Using a severity index, we compared samples collected on different dates and from different locations according to age and testis weight. No significant variations were noted among any of the groupings. Further investigation is needed to determine whether the intersex condition in shoal bass is severe enough to warrant concern ...


Phylogeny, Life History, And Ecology Contribute To Differences In Amphibian Susceptibility To Ranaviruses., J. Hoverman, Matthew Gray, Nathan Haislip, Debra Miller Dec 2010

Phylogeny, Life History, And Ecology Contribute To Differences In Amphibian Susceptibility To Ranaviruses., J. Hoverman, Matthew Gray, Nathan Haislip, Debra Miller

Debra L Miller

Research that identifies the potential host range of generalist pathogens as well as variation in host susceptibility is critical for understanding and predicting the dynamics of infectious diseases within ecological communities. Ranaviruses have been linked to amphibian die-off events worldwide with the greatest number of reported mortality events occurring in the United States. While reports of ranavirus-associated mortality events continue to accumulate, few data exist comparing the relative susceptibility of different species. Using a series of laboratory exposure experiments and comparative phylogenetics, we compared the susceptibilities of 19 amphibian species from two salamander families and five anurans families for two ...


Ecopathology Of Ranaviruses Infecting Amphibians., Debra Miller, Matthew Gray, A. Storfer Dec 2010

Ecopathology Of Ranaviruses Infecting Amphibians., Debra Miller, Matthew Gray, A. Storfer

Debra L Miller

Ranaviruses are capable of infecting amphibians from at least 14 families and over 70 individual species. Ranaviruses infect multiple cell types, often culminating in organ necrosis and massive hemorrhaging. Subclinical infections have been documented, although their role in ranavirus persistence and emergence remains unclear. Water is an effective transmission medium for ranaviruses, and survival outside the host may be for significant duration. In aquatic communities, amphibians, reptiles and fish may serve as reservoirs. Controlled studies have shown that susceptibility to ranavirus infection and disease varies among amphibian species and developmental stages, and likely is impacted by host-pathogen coevolution, as well ...


Streptococcus Phocae Isolated From A Spotted Seal ( Phoca Largha) With Pyometra In Alaska., K. Hueffer, C. Lieske, L. Mcgilvary, R. Hare, Debra Miller, T. O'Hara Dec 2010

Streptococcus Phocae Isolated From A Spotted Seal ( Phoca Largha) With Pyometra In Alaska., K. Hueffer, C. Lieske, L. Mcgilvary, R. Hare, Debra Miller, T. O'Hara

Debra L Miller

A spotted seal harvested by subsistence hunters in Kotzebue Sound, Alaska (USA), showed a grossly enlarged uterus and associated lymph nodes. Streptococcus phocae was isolated from the purulent uterine discharge. Histopathologic examination revealed inflammation that was limited to the uterine mucosa. Lymph nodes draining the affected organ were reactive but no evidence of active infection was found in the lymph nodes. This report is the first Streptococcus phocae isolated from spotted seals as well as the first report of pyometra as the main pathologic finding associated with this pathogen. Isolation of this pathogen from Alaska expands the reported range to ...


Low-Dose Immunization Of Northern Bobwhites (Colinus Virginianus) With Eimeria Lettyae Provides Protection Against A High-Dose Challenge, Richard Gerhold Jr., A Fuller, R Beckstead, L Mcdougald Nov 2010

Low-Dose Immunization Of Northern Bobwhites (Colinus Virginianus) With Eimeria Lettyae Provides Protection Against A High-Dose Challenge, Richard Gerhold Jr., A Fuller, R Beckstead, L Mcdougald

Richard W. Gerhold Jr., DVM, MS, PhD

To determine whether northern bobwhite quail (Colinus virginianus) could be immunized against Eimeria lettyae by a low-dose inoculation of oocysts, we inoculated 30 birds each with either 100 or 1000 oocysts at 2 days of age (given orally by pipette). Four weeks after immunization, the immunized birds and unimmunized controls were challenged with 1 x 10(6) E. lettyae oocysts. Eight days after challenge, birds were killed and weighed, and their intestines examined for gross lesions. Effectiveness of the immunization was measured by analyzing weight gain, intestinal lesions, severity of diarrhea, feed conversion ratio, and oocyst production. After challenge, birds ...


An Unusual Case Of Coccidiosis In Laboratory-Reared Pheasants Resulting From A Breach In Biosecurity, Richard Gerhold Jr., S Williams, A Fuller, L Mcdougald Aug 2010

An Unusual Case Of Coccidiosis In Laboratory-Reared Pheasants Resulting From A Breach In Biosecurity, Richard Gerhold Jr., S Williams, A Fuller, L Mcdougald

Richard W. Gerhold Jr., DVM, MS, PhD

An outbreak of coccidiosis in laboratory-reared Chinese ring-necked pheasants (Phasianus colchicus) resulted in high morbidity and moderate mortality. The outbreak was associated with a breach in biosecurity caused by the cleaning of a sewer line with a mechanical device, resulting in extensive splattering of fecal material throughout the "clean room" where birds were held prior to use in coccidiosis experiments. Mortality and morbidity in the affected birds were seen exactly 5 days after the incident, after birds had been moved to another room for experimental use, corresponding closely with the known prepatent or preclinical period of Eimeria phasiani and Eimeria ...


Mercury Poisoning In A Free-Living Northern River Otter (Lontra Canadensis), J Sleeman, D Cristol, A White, D Evers, Richard Gerhold Jr., M Keel Jun 2010

Mercury Poisoning In A Free-Living Northern River Otter (Lontra Canadensis), J Sleeman, D Cristol, A White, D Evers, Richard Gerhold Jr., M Keel

Richard W. Gerhold Jr., DVM, MS, PhD

A moribund 5-year-old female northern river otter (Lontra canadensis) was found on the bank of a river known to be extensively contaminated with mercury. It exhibited severe ataxia and scleral injection, made no attempt to flee, and died shortly thereafter of drowning. Tissue mercury levels were among the highest ever reported for a free-living terrestrial mammal: kidney, 353 microg/g; liver, 221 microg/g; muscle, 121 microg/g; brain (three replicates from cerebellum), 142, 151, 151 microg/g (all dry weights); and fur, 183 ug/g (fresh weight). Histopathologic findings including severe, diffuse, chronic glomerulosclerosis and moderate interstitial fibrosis were ...


Molecular Confirmation Of Parelaphostrongylus Tenuis Infection In A Horse With Verminous Encephalitis, M Tanabe, Richard Gerhold Jr., R Beckstead, A De Lahunta, S Wade Jun 2010

Molecular Confirmation Of Parelaphostrongylus Tenuis Infection In A Horse With Verminous Encephalitis, M Tanabe, Richard Gerhold Jr., R Beckstead, A De Lahunta, S Wade

Richard W. Gerhold Jr., DVM, MS, PhD

No abstract provided.