EXAM 1 - 10 Lectures Flashcards
health
the state of an organism when it functions optimally without evidence of disease or abnormality
disease
deviation from normal function of any body part, organ, or system that is manifested by a characteristic set of symptoms and signs
pathogen
any disease-producing agent or microorganism
etiology
cause of disease
wildlife diseases
are multifactorial and can involve complex interactions between the pathogen, host, and environment
vary within and between populations
spectrum of disease
increasing with changing and loss of biodiversity
- increasing interaction
- improved diagnostics and surveillance
one health
concept recognizing that the health of humans is connected to the health of wildlife, domestic animals, and the environment
reason to study wildlife diseases
wildlife impact and management
- determine the cause of and significance of disease and identify methods to reduce disease and the impacts on wildlife
- endangered species may suffer disastrous losses from disease
disease of human or agricultural significance
- determine role of wildlife as a reservoir or source of disease for domestic animals or humans
environmental health or habitat loss
- can be indicators of contaminated habitats - can be associated with habitat loss
disease of high visibility and/or concern
- public communication
assess the role of humans on wildlife health
to learn
how do we investigate wildlife diseases
study the impacts of disease on individuals and/or populations
challenges with wildlife disease investigations
detection of sick and dead animals
difficulty obtaining samples for surveillance
difficulty quantifying disease
lack of knowledge
funding
lack of validated test
problems related to science and technology
managing wildlife diseases
do we have to?
very challenging and often unsuccessful
- public attitude
- delivery of treatment
prevention
prevent disease from occurring or becoming establised
control
reduce or maintain the prevalence and impact of disease
eradication
eliminate the pathogen or disease
difficult or cannot be done
pathology
the study of disease, especially the structural and functional changes produced by them
extremely useful in wildlife diseases
- clinical signs often absent, subtle, nonspecific
- history may not be available
pathogenesis
mechanism of disease
morphologic changes
structural changes in cells or tissues characteristic of disease
clinical significance
how morphologic changes result in clinical signs and disease
clinical pathology
more focused on antemortem samples/data
results from lab tests - fluids
cytology
less commonly used for wildlife disease
cytology
clinical pathology
microscopic examination/evaluation of cells
anatomic pathology
necropsy
histology
necropsy
postmortem examination of the body
histology
microscopic examination of structure, function, and morphology of tissues
lesions
abnormal change in structure of organ, tissue, or cell due to disease
not all abnormal appearing tissues are lesions
distribution provides insight into pathogenesis and potential etiology
focal
single lesion
multifocal
numerous lesions
locally extensive
one lesion expanding outward
effusions
escape of fluid into a space or cavity from tissue or organ
beginning - named for composition
end - named for location
aspirate
hemorrhage
escape of blood from damaged or dysfunctional blood vessels
due to damage to blood vessels, blood clotting disorders
can be primary or secondary
may bee seen with edema or musculoskeletal lesions
necrosis
death of cells or tissue
can look different depending on tissue, cause, and duration of lesion
often pale, soft, friable, and demarcated margins
can look read if vasculature involved
inflammation
protective response to a diversity of cell injuries
-itis
can be associated with infection
acute or chronic
acute inflammation
consists of vascular and cellular components
- increase blood flow
- increase blood vessel permeability
- migration of permeability
- leukocyte recruitment
accumulation of fluid and inflammatory cells
- remove cause of injury
- healing and repair
signs
- rubor - red
- tumor - swelling
- calor - hoot
- dolor - pain
- laesa - lose of function
chronic inflammation
lymphocytes, macrophages, plasma cells infiltrate injured area
tissue destroyed by inflammatory cells
repair with fibrosis and angiogenesis
peracute
faster than acute
lightning, trauma, infection
may not have lesions - died too quickly
neoplasia
unregulated cell proliferation
some are spontaneous
uncommon in wildlife - don’t live long
most often associated with infectious agents
other etiologic factors
- chemicals
- diet
- irradiation
- hormones
- genetic inheritance
- pharmacologic agents
tumor
any tissue mass
benign or malignant
benign
ends in - oma
slower growth rate
not locally invasive
not likely to metastasize
well differentiated
malignant
- carcinoma - if ectodermal or endodermal
- sarcoma - if affecting connective or soft tissue
fast growth rate
locally invasive
more likely to metastasize
poorly differentiated
pathology challenges for wildlife cases
not all abnormal tissues are lesions
normal anatomy
- extremely diverse
- seasonal changes
post-mortem change
artifact
parasites
distinguishing between antemortem vs postmortem changes
autolysis
artifact
changes in tissue that occur right at the time of death or soon after
euthanasia
autolysis
disintegration of cells or tissues by endogenous enzymes
postmortem
not necrosis - cell death
epidemiology
the study of the distribution and determinants of health-related events in a population
utilization of this information for diagnosis, prevention, control of disease
distribution
who, what, when, where, why
defining disease/health issue
understanding circumstances that result in disease event
determinants
risk factors
types of epidemiology
descriptive
analytical
descriptive epidemiology
examine and characterize the distribution of disease in a population
analytical epidemiology
investigating a hypothesis about the cause of disease by studying how exposures relate to disease
modeling
interface
a point where two systems can meet and interact
share diseases
enzootic disease
occurs in a population at a regular, predictable, or expected rate
endemic
epizootic disease
appears at a time or place where it does not normally occur or with a frequency substantially greater than expected
epidemic
prevalence
frequency of occurrence of disease within a group at a specific point in time
period prevalence - with a period of time
incidence rate
number of new cases within a group during a specific period of time
mortality rate
frequency of occurrence of death in a defined population during a specific time interval
case fatality rate
proportion of persons with a disease that die
measure of severity
only in infected
pathogenesis
development of a disease and the chain of events leading to that disease
mechanism
risk assessment
process to identify hazards/threats and analyze what could happen if they occur
probability of disease/infection occurring
consequences of disease/infection
can we manage
clinical sign
objective evidence of disease observed by a medical professional
syndrome
combination of clinical signs resulting from a single cause
congenital
disease that is present at or before birth
acquired
disease that occurred or was acquired after birth
differential diagnosis procedure
systematic diagnostic method t identify the etiology of disease where multiple possibilities exist based on clinical signs or symptoms
compile information
create a list of possible etiologies - rule outs
formulate a diagnostic plan - priority testing
sue diagnostic results to remove or add to list
diagnostic success is influenced by
well defined objectives
detailed history
appropriate samples
diagnostic assay
diagnosotic assays
direct and indirect
direct assay
identification of etiology itself
indirect assay
identification of measurable response too the etiology
ideal diagnostic assay
well-characterized
affordable
user friendly
rapid
sensitive and specific
minimal equipment
widely available
works on all species
test sensitivity
number of positive samples correctly classified as positive
test specificity
number of negative samples correctly classified as negative
bloodwork and urinalysis
not used frequently in wildlife
requires live or recently dead animals
need normal values
fecal analysis
presence of parasite does not always indicate disease
cytology
microscopic examination/evaluation of cells
inexpensive and quick
non-invasive
can diagnose limited things
histopathology
microscopic examination of structure, function, and morphology of tissues
can identify lesions and pathogens
more invasive an require reagents/equipment for processing
staining - special stains
diagnostic imaging
radiology +/- ultrasound
radiology more common in wildlife
culture/isolation
gold standard
viruses, bacterial, fungi, protozoa
procedures vary greatly
bacteria/fungi - artificial media
viruses - cells
any body fluid, tissues, swabs
tissue storage and handling is critical
molecular diagnostics
pcr - detects dna
sensitive
not live pathogen
serology
detect antibodies - vaccination impacts, dead population
evidence of past exposure
easy to perform
only detects prior exposure - time to develop immune response
challenging to get serum from dead animals
rapid tests
for antigen or antibody detection
direct or indirect
little skill
speed
portable
specific
poor sensitivity
may not be validated in wildlife
immunodiagnostics
uses and antigen-antibody reaction as primary means of directions
good for viruses
fluorescent antibody test - rabies
immunohistochemistry - formal fixed paraffin embedded tissues
toxicology
less species specific
detect a specific compound in body
idea of what you’re looking for
expensive
large amount of sample
wildlife management
practical ecology of all vertebrates and their plant and animal associations
body of decisions/actions for utilization and welfare of wildlife population and their habitats, balancing their needs with those of people
north american model
wildlife as a public trust resource
elimination of market hunting
allocation by law
killing for only legitimate purposes
wildlife as an international resource
science based policy
democracy of hunting
direct transmission
direct and immediate transmission
physical contact
fecal oral
ingestion
indirect transmission
transfer by intermediate item or oransim
fomites
environment
intermediate host
vector
host range
all the organisms that a pathogen is capable of infecting
infectivity
the ability of microorganism to infect or transmit
virulence
the capacity of any infective organism to cause disease
chronic sequelae
aftermath of infection
long covid
endoparasite
live inside the hosts body
ectoparasite
lives outside the hosts body
definitive host
host in which parasite develops to an adult or sexually mature stage
intermediate host
host which contains the immature (non reproducing) stage of parasite but is required to complete life cycle
paratenic (transport host)
host in which there is no development and is not required to complete the life cycle
aberrant host
host in which the parasite cannot complete its development
dead end
spillover
vector
organism that transmits a parasite or pathogen from one host to another
mechanical vector
transport no parasite development
biologic vector
necessary for parasite reproduction or development
direct life cycle
parasite transmitted from definitive host to definitive host
indirect life cycle
requires one or more intermediate hosts
pre-patent period
when parasite infects host until shedding is detected
incubation period
parasite infects host until clinical signs are detectable
protozoa
single celled
microscopic
high reproductive potential
very diverse
arthropods
chitin exoskeleton, segmented body, jointed appendages
multiple life stages
primarily external
sexual reproduction
arachnids
2 body segments, 4 paired legs, no wings
mitees, spiders, ticks
insects
3 body segments, 3 paired legs, wings
lice, mosquitos
flatworms
platyhelminths
digestive tract incomplete or absent
trematodes - flukes
complex life cycles - least 2 hosts
cestodes - tapeworms
indirect life cycle
adults in intestinal tract of host
roundworms
unsegmented
cylindrical
complex digestive system
separate sexes
direct or indirect life cycles
gram stain
positive - blue
negative - red
bacteria
primary pathogens or opportunistic
variety of mechanisms to produce disease
- toxins
- highly invasive
- interference with host metabolism
- stimulation of host response
common diagnostics for bacteria
culture
microscopy
diagnostic immunology
pcr
viruses
microscopic
obligate intracellular micrope
dependent on host
envelope - easier to inactivate
classified by
- structure/morphology
- serology
- nucleic acid
host range
control host machinery
variable gross and histologic lesions
viral virulence
ability of virus to cause disease in an infected host
virus diagnosis
inclusion bodies
virus isolation
pcr
immunofluorescence
serology
balancing mechanisms of natural systems
limit impact of disease
altered by human activities
negative outcomes of artificial wildlife activities
increase disease or spread of disease
introduction to new host or area
novel diseases
artificial wildlife activities
supplemental feeding and baiting
wildlife rehab
translocation of native wildlife
captive propagation and release
high fence operations
vaccination/treatment
pets and feral animals
bird feeder diseases
songbirds
winter months
- stress
- congregate birds
- increased direct/indirect contact
implication for human and domestic animal health
salmonellosis
platform feeders
most commoon
s.typhimurium bacteria
epizootics
high mortality
sping and winter
fecal oral
chronic carriers
feeder sanitation
important pathogen of poultry
identifying strain
salmonellosis clinical signs
depressed
ruffled feathers
labored breathing
swollen eyes
lesions
- swollen liver or splean
- yellow nodules or plaques
mycoplasmosis
tube feeder
bacteria m.gallisepticum
disease of poultry
- chicken - chronic respiratory disease
- turkey - infectious sinusitis
distinct strain in finches
winter months
chronic carrier
bird feeder sanitation
transmission
- bird to bird
- inhalation
- contaminated surfaces or food
how to create a wildlife disease - antibiotics created chronic carriers
mycoplasmosis clinical signs
conjuctivitis
swollen eyes, discharge
weight loss
bird feeder diseases
salmonellosis
mycoplasmosis
asperrgillosis
trichomoniasis - baths
avian pox
bird feeder diseases general recommendations
clean feeders
monitor for disease
high quality food
no sharp edges
give space
feeding
intentional placement of food in wildlife habitat, seasonally or year round, for use by wildlfie
baiting
food or food product intentionally placed for the purpose of attracting fame species to enhance the opportunity to harvest
why do people feed and bait
improve condition of individual animals
enhance survival
reduce agricultural damage
enhance recreational opportunities
direct causes of disease/harm - feeding and baiting
rumen acidosis
clostridial diseases
aflatoxicosis
indirect causes of disease/harm - feeding and baiting
aggressive behavior
degradation of habitat
density dependent diseases
- cwd
- tb
- brucellosis
rumen acidosis
grain overload
abrupt change from high fiber to low fiber diet
increased lactic acid production
severity varies
change in microbial population
recumbent, quiet, staggering, diarrhea
can be fatal within 1-3 days
clostridium enterotoxemia
abrupt change from high fiber to low fiber diet
provides environment for c.perfringes to replicate and produce toxin
hemorrages on gi tract, muscle, heart, or bloody intestines
grain/corn in rumen
culture
PCR for toxin
bovine tb
mycobacterium bovis
infect most mammals
historically cattle disease
primary transmitted through respiratory secretions
strong correlation between tb in deer and artificial feeding
wild turkeys
captive propagation and release
unsuccessful
negative impact on wild turkeys
translocation
rabies
high fenced enclosures and captive cervids
artificial breeding for meat and larger antlers
potential risks:
- lack of population control
- translocation of animals
- mixing species
- artificial feeding
- use of vaccines
negative impacts:
- disease
- genetics
- public perception
- privatization of wildlife
- regulatory authority
vaccination of wildlife
use of domestic animal treatment protocols in wildlife without safety or efficacy data can be dangerous
black footed ferret
wild animal
animal that has a phenotype unaffected by human selection and lives independent of direct human control
captive wild animal
animal that has a phenotype not significantly affected by human selecting but that is captive or otherwise lives under human control
feral animal
anmial of a domesticated species that now lives without direct human control
exotic species
a species, including its seeds, eggs, or other biological material capable of propagating that species, that is not native to a habitat
native species
species that, other than as a result of an
introduction, historically occurs in a particular habitat
invasive species
an exotic species whose introduction into an
ecosystem in which the species is not native is likely to cause
environmental, economic, or public health harm.
– Ecosystem boundary, not political
– Do not need to be from another country or region
– Not all exotic species are invasive; need to be adapted to do well
Native species/communities evolve in an ecosystem with
checks and balances that limit growth of any one species
Invasive species do not have the same checks and balances
and populations can increase dramatically
Most invasive species spread through human activities.
traits that allow invasive species to outcompete native species
– Rapid growth
– High reproductive potential
– High dispersal
– Human associations
– May not have natural predators
– Tolerant of a wide-range of environmental conditions
– Adaptable
direct impacts of inasive species
– Predate upon native species
– Competition
– Negative effect on
reproduction
– Source of disease
indirect impacts of invasive species
- Change food web
– Decrease biodiversity
– Alter ecosystem
invasive species have negative impacts on
– Resources/Environment
– Wildlife
– Domestic animals
– Economy
– Human health
avian pox
introduced by invasive species
poxvirus - dna - vary in host range and virulence
nodular skin lesions on face and legs
transmitted though mosquitoes and inhalation/ingestion
avian malaria
introduced invasive species
protozoan parasites (plasmodium sp)
numerous species
p. relictum in Hawaii
non specific clinical signs
- anemia, hepatomegaly, splenomegaly
- infected birds weak and inactive
transmitted by mosquitoes
cats
indoor, outdoor, stray, feral, free roaming
most popular pet in us
most abundant carnivore in ud
invasive
indoor live longer
why are cats invasive
– Non-native; widespread
– High reproductive potential
– Predatory behavior
– Competition
– Quantifying wildlife mortality due to cats is impossible to
accurately quantify, but all measures indicate it is very high
– Extinctions
– Indirect impacts
– Disease - rabies, toxoplasmosis, hookworm, toxocariasis, bartonellosis, typhoid, plague, tularemia
parthenogenetically
females can produce eggs without males
produce only females
asian longhorn tick - theileria orientalis ikeda
protozoan parasite
cs similar to anaplasmosis - anemia, fever, lethargy
virgina
no approved treatment in us
feral hogs
eurasian wild boar
domestic escapes
wild born pig or hybrid
predator on sheep and goats
consume vegetation
predatory on wild turkey nests, qual nests, sea turtle nests
feeding behavior can have direct impacts on local sensitive species population
feral pigs - swine brucellosis
Bacterial infectious disease of animals and humans
Abortions and reproductive organs infections in hogs
Humans – severe flue like symptoms and vary to crippling
arthritis or meningitis.
Wildlife- can be passed on and remain as a secondary host,
does not cause mortality but may pass to humans.
NO cure, treated with high doses of antibiotics for extended
periods to hopefully clear infection
Wide geographic distribution of feral swine
feral pigs - pseudorabies - mad itch
Viral disease of central nervous system in swine
Transmission by venereal route in swine, contact route in domestic animals (fatal in
secondary hosts).
Control/eradication program in US – PRV free in commercial swine operations
Reservoir in US – feral swine
Occasional outbreaks in swine with outdoor access/access to feral swine
Transmitted – direct contact or indirect on fomites
Also can infect dogs, cats, cattle, goats, sheep. Has caused mortality in wildlife (black
bear, coyote, mink, raccoon, Florida panther).
feral hogs - e coli 0157
2006 Spinach Outbreak – 26 states and Canada reporting 205
cases of illness and 3 deaths ($$$$)
5 – 10% exposures develop life-threatening illness
Can affect crops, pastures, and water supply
High potential for contamination of meat while processing
feral pigs - leptospira interrogates
Bacteria, infectious to most mammals
Multiple serovars
Multiple transmission routes, often through water
Classified as a re-emerging pathogens
Human cases
domestic animal cases
feral hogs - influenza
Influenza- Swine have receptors in common with both birds and mammals
Provide opportunity for mixed infections and genetic reassortment between
avian, human, and swine influenza
Feral swine have been documented carrying 4 sub-types of swine influenza
Both human (H3N2) and avian (H1N1) sub-types have been documented in
swine
Feral swine habitat brings them in contact with humans and waterfowl
feral hogs - foreign animal disease
FAD- disease not currently found in the United States
* Nationally reportable disease, highly contagious, economic impacts
* FAD status impacts important national export of products
* Introduction of FAD could cost US $200-500 billion
Classical Swine Fever (CSF)
Foot and Mouth Disease (FMD)
African Swine Fever (ASF)
feral hogs - classical swine fever
- Viral Disease swine disease that is highly contagious
- It can be transmitted via blood,
saliva, nasal discharge, urine, feces or tissues and is easily carried in fomites. - Transmission can occur though direct contact or the consumption of infected tissue
- Infection in 214 days, causing high fever, diarrhea, hemorrhages, abortions, and death
-swine near landfills, ports, domestic swine facilities are all high risk
feral hogs - african swine fever
African Swine Fever Virus (ASFV)
No vaccine/no treatment
High morbidity and high mortality – naïve populations
Never diagnosed in US
Domestic and wild pigs
feral hogs - asf signs and symptoms
Develop 3-15 days after infection
Mimic signs seen with several other swine diseases
(Salmonella, PRRS, Erysipelas, CSF)
Include: high fever; decreased appetite; weakness;
red, blotchy skin or skin lesions; diarrhea,
vomiting, coughing and difficulty breathing
feral hogs - asf transmission
Direct contact with infected pigs (oronasal)
Virus shed in all tissues and body fluids
Indirect contact with fomites
Tick vectors (Ornithodoros soft ticks)
Feeding of uncooked/improperly cooked pork scraps
lead toxicosis
also called plumbism
all birds susceptible - has effected most waterfowl species
avian scavengers and raptors
result of absorption of lead into the blood
most cases due to ingestion - acidic environment
joints or inflamed tissue
sources vary within avian group
waterfowl - lead shot
loons - fishing lures
albatross - lead paint from buildings
lead toxicosis - proventriculus and gizzard
breaks down lead for absorption
releases into blood
low ph
grinding action of gizzard
smaller fragments can absorb faster and harder to regurgitate
accumulates in body over time
lead toxicosis - once absorbed
lead mimics calcium in various biochemical and cellular processes
disrupts normal function of multiple organ systems
- binds enzymes
- neurotoxin and neuphrotoxin
- disrupts rbc development
- depression of immune system
- musculoskeletal system - muscle contraction
lead toxicosis - clinical signs
acute, chronic, sub lethal
non specific
- reluctant or unable to fly
- lag behind other birds
- unsteady gait
- changes in vocalization
chronic disease
- weak and lethargic
- doesn’t attempt to escape when captured
- emaciated
- neurological signs
lead toxicosis - clinical signs
very poor nutritional condition
esophageal impactions - waterfowl
green stain around vent
gall bladder distension
green stained gizzard
finding shot in gizzard
myocardial degeneration/necrosis
lead toxicosis - dependent on multiple factors
environment
- shallow water
- sediment
host
- diet - high carb decreases ph
- nutritional status
- age - younger
- species
- sex
- underlying disease
very low amounts can result in toxicity
lead toxicosis - diagnosis
suggestive on lesions/signs and presence of lead in ventriculus - not always present
radiographs to identify metal opacity
lead testing for confirmation
- liver and kidney
- whole blood (antemortem)
- no concentration in a tissue can be diagnostic by itself
lead toxicosis - treatment
possible but challenging
- expensive and time consuming
- prognosis depends on level of toxicity but often poor
- euthanasia or non-releasable status is common outcome
gastric lavage or surgery to remove current sources
chelation therapy
- frequently
- form complexes with lead and eliminate in urine
supportive care
rehab centers are expensive
lead toxicosis in eagles
primarily from ammunition in animal carcasses or parts
- gut piles
- animals shot and not retrieved
- animals shot and left in field - groundhogs
lead fragmentation
- depends on ammunition, if it hits bone
- rinsing carcass doesn’t remove lead
lead toxicosis - prevention
non lead ammunition - copper doesnt fragment
lead
- proper recovery or disposal of animal carcass or parts
- bury or cover carcass parts
education and productive discussions
lead toxicosis - one health
personal harvest
donated venison - ethics
education
