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WILDLIFE DISEASES
REPTILES
Pavel Široký
Department of Biology and Wildlife Diseases
FVHE, VFU Brno
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For this reason, this file is intended only for
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Specifics of wildlife reptiles
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Hidden life-style
Little interest of public, mostly just captivity
Frequent prejudice, economically less important
Comparing to others – absence of spectacular die-offs
Wide spectra of identified pathogens – unknown influence
Problematic exact etiology
Recent situation
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Mostly basic research on wild reptiles
Less known influence of pathogens on populations – reptiles
are complicated model
Accent on endangered species – large species, turtles +
tortoises
Non-infectious diseases
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Traumas – traffic, agriculture, entertainment
Pollutants
Pollution by light – sea turtles after hatching follow lightest
area of horizon – sea surface x hotels and touristic
resorts – disoriented, death far from water
Intoxication of reptiles
Simple poisoning – pesticides, oil products, accidents
Interferences with hormones – hormone aromatase control
levels of sex hormones during early ontogeny – TSD –
sex depending on temperature.
Interference with aromatase influencing its activity causing
biased sex-ratio from natural to one (mostly female) sex
– break of natural balance
Intoxication by DDT
Alligators – high concentration of DDE in eggs,
reproduction failure
Lower viability of clutch – higher juvenile mortality,
disbalance of steroid hormones, abnormal gonadal
development
Altered embryonic development of sex of juveniles
Estrogenic activity of DDT at American sliders (Trachemys
scripta)
Intoxication of snapping turtles by PCB
Snapping turtles (Chelydra serpentina) – sentinel species,
freshwater ecosystem, accumulation of pollutants,
longevity, high proportion of fat tissue, seddentary lifestyle, omnivorous and predators
Correlation of PCB levels in turtles and environment
High incidence of abnormal development, deformation of
tail, legs, missing claws, cranial deformities, small
hatchlings
Negative anthropogenic influence
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Simple pollution
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Big amount of wastes around human settlements, river
estuaries, sea shore
Big troubles represent plastic bags for sea turtles feeding
on jellyfish – ingestion – linear body, troubles with GIT,
die-off
Mass dying of gavials
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2007 – big die-off of gavial in river Chambala
Unknown etiology
Suspect intoxication or infection
Veterinary investigation – gout
Intoxication accepted as cause??
Infections of reptiles
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Wide spectrum of etiology
Significance and impacts understudied
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Zoonoses – Salmonella, Borrelia, Rickettsia, Coxiella
Transmission to domestic animals – die-off or decrease
in profit – Ehrlichia
Impact on reptilian populations?
Reptilian ectoparasites
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Barnacles, leeches, ticks, insects
Endoparasites
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Numerous, usually unknown effect on host species
Pentastomids – worm-like, intermediate hosts also
mammals, zoonotic potential, dangerous in captivity, viperid
snakes, but also other reptiles
Porocephalus crotali – visceral pentastomiasis of dogs
Respiratory tract
Armillifer sp.
Herpesvirus infection
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Herpesvirus infection of tortoises
THV-1, THV-2, tortoise Gopherus, Geochelone,Testudo
Die-off 1200 out of 2200 imported tortoises G. chillensis
during 3 months
Necrotic changes at nasal, tongue, and pharyngeal region
Stomatitis-glossitis, stomatitis-rhinitis syndrome
Per-acute, acute development, inability swallowing, caseous
discharge, apathy, death (T: acyclovir, gancyclovir????)
Herpesvirus infection
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Herpesvirus infection of sea turtles
LETD – Lung, Eye, and Trachea Disease - LETV, affected
particularly green turtles (Chelonia mydas)
Open mouth above water surface, harsh respiratory sounds
Fast spreading – pneumonia, necrotic areas at mouth,
glottis, tongue, trachea, histological – focal to diffuse
degeneration and necrosis of mucosa
Herpesvirus infection
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Grey patch disease
Hatchlings (56-90 days) of green turtles (C. mydas) in
aquaculture – conservation activities
Most severe in summer - water temperature above 30 C,
crowded tanks and pollution
Small circular papular lesions, coalesced into spreading
patches
Fibropapillomatosis of European green lizards
EID in wildlife reptiles
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Fibropapillomatosis of sea turtles
One of most serious health problem of wild reptiles
Etiology unknown – confirmed presence of virus, influence
by pollutants?, multifactorial disease??
Hatchlings health – infected during growth and maturity, first
small papillomas at eye corner, later considerable growth,
generalization, death
25-30% affected turtles suffer also by internal tumors –
fibroma, myxofibroma, fibrosarkoma in lung, kidney and
heart
Mycoplasma infection of tortoises
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URTD – Upper Respiratory Tract Disease
M. testudinis – first discovered, most probably commensal
Big trouble- URTD in population of Gopherus agassizii
Serous, mucous and purulent nasal and ocular discharge,
conjunctivitis, palpebral edema, most serious changes –
nasal cavity and in structures between nares and eyes
Discovered also in other species – Gopherus spp. Testudo
spp. – detected various bacteria, etiology unknown
Mycoplasma infection of tortoises
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Detected M. agassizii – correlation with disease occurrence
Experimental infection confirmed etiology of M. agassizii
Other species discovered M. testudineum
Serious complication of conservation projects, many
suffering species are endangered
Risk of spreading via in situ – ex situ projects
Do not release confiscated or in captivity living turtles into
intact natural populations
Inevitable vet supervision!!!
Literature