debra l. miller, dvm, phd - university of...
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Comparative Pathology of Comparative Pathology of RanaviralRanaviral Disease among Disease among
Amphibians, Reptiles and FishAmphibians, Reptiles and Fish
Debra L. Miller, DVM, PhDDebra L. Miller, DVM, PhD
Center for Wildlife Health and Center for Wildlife Health and Department Pathobiology Department Pathobiology University of TennesseeUniversity of Tennessee
Amphibians
Swelling (most often edema) Erythema, Ulcerations
Photo courtesy Nathan Haislip
D. Green, USGSPhoto, Betsie B. Rothermel
Photo courtesy Nathan Haislip
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May vary by life stage May vary by life stage [adults most reported from Europe, but elsewhere too][adults most reported from Europe, but elsewhere too]
Photo courtesy Nathan Haislip
Photo courtesy Nathan Haislip
Varies by host (species)Varies by host (species)--susceptibility & isolatesusceptibility & isolate(e.g., mortality: RI [ranaculture isolate] (e.g., mortality: RI [ranaculture isolate] vsvs FV3)FV3)
Cope’s tree frog (~70% RI; ~40% FV3)
Photo courtesy Nathan Haislip
Wood frog (~ 100% for both)
Bullfrog (~10%; 0% FV3)
Cope s tree frog (~70% RI; ~40% FV3)Photo courtesy Nathan Haislip
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Internal lesions
hemorrhage
mesonephros
pale, swollen organsfat bodies
spleen
tan areas [necrosis] on organs
HistologyHistology
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HistologyHistology
Southern Southern Leopard Leopard Frog: Frog:
ll
control
spleenspleen
FV3ranaculture isolate
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Southern Southern Leopard Leopard Frog: Frog: kidkid
control
kidney kidney ((mesonephrosmesonephros))
FV3ranaculture isolate
Pallid sturgeon isolate Ranaculture isolate
Wood Frog Spleen
FV3 Box turtle isolate
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In North GeorgiaIn North Georgiaconcurrent in morbid concurrent in morbid Notophthalmus viridescens Notophthalmus viridescens andandLithobates clamitansLithobates clamitans. .
Photo, Betsie B. Rothermel
RanavirusRanavirus--positive animalspositive animalsplus: Parasites increasedplus: Parasites increased
In Tennessee: Die-off in L. clamitans, L. catesbeianus, N.
viridescens
plus: Parasites increasedplus: Parasites increased
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What about reptiles?What about reptiles?
SCWDS caseSCWDS case(slides courtesy of Dr. Mark Ruder)(slides courtesy of Dr. Mark Ruder)
Eastern box turtle (Eastern box turtle (TerrapeneTerrapene carolinacarolina carolinacarolina))
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Gross Findings (cont.)Gross Findings (cont.)
5 mm
Some microscopic Some microscopic ffindingsindings
Myofibers disrupted
Ulcerated crust on oral mucosa
Disrupted muscle fibers
Heterophillic vasculitis
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DiagnosticsDiagnostics RanavirusRanavirus isolated in tissue cultureisolated in tissue culture
Partial sequencing yielded Frog virus 3Partial sequencing yielded Frog virus 3–– Partial sequencing yielded Frog virus 3Partial sequencing yielded Frog virus 3
PCR on PCR on oropharyngealoropharyngeal swab and nasal swab and nasal flushflush–– RanavirusRanavirus –– positivepositive–– HerpesvirusHerpesvirus and and MycoplasmaMycoplasma -- negativenegativepp y py p gg
MycoplasmaMycoplasma culture of nasal flushculture of nasal flush–– NegativeNegative
What about water turtles?What about water turtles?
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Concurrent infections compound the diagnosis
ParasitismParasitism ParasitismParasitism–– Soft shells Soft shells
Spirorchid eggs (often systemic) Entomeoba spp trophozoites
(intestines only)
Bacterial EnteritisBacterial Enteritis–– SSlidersliders
Current investigation:Current investigation:
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What about Fish?What about Fish?
Ecchymosis and petechiation on the ventral surfacePale gills and liver
FishFish--creek chubcreek chub
Pale gills and liverFriable kidneys and liver Lesions/organs PCR positive for ranavirus
Photo courtesy Emilie Travis
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Pallid Sturgeon Isolate Pallid Sturgeon Isolate from mortality eventfrom mortality event
Photos Courtesy Tom Waltzek
Hematopoietic necrosis; tubular epithelial necrosis
E d h liEndothelium
Endothelial necrosis
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Liver: Portal triad: endothelial necrosis (arrow) Also: hematopoietic necrosis (arrow head).
Planned investigation:Planned investigation:
Pilot study: fish challenges (Fall 2011)
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AcknowledgementsAcknowledgements
Matt GrayMatt Gray Sandy BaldwinSandy Baldwin Jason HovermanJason Hoverman Betsie RothermelBetsie Rothermel Mark RuderMark Ruder Tom WaltzekTom Waltzek Nate HilzingerNate Hilzinger
Lisa WhittingtonLisa Whittington Dallas IngramDallas Ingram Diane Diane RouseyRousey Kim BridgesKim Bridges Melissa GandyMelissa Gandy
Becky HardmanBecky Hardman Nathan HaislipNathan Haislip Roberto BrenesRoberto Brenes Sean RoonSean Roon
Eloise Eloise StyerStyer Emilie TravisEmilie Travis Kevin KeelKevin Keel Various zoos and aquariaVarious zoos and aquaria
Questions?Questions?