Wildlife Medicine Flashcards
parasitic zoonoses wildlife diseases wildlife zoonoses
1
Q
Which of the following are zoonotic?
a. ancylostoma caninum
b. toxocara canis
c. dirofilaria immitis
d. parelaphostrongylus tenuis
A
a. ancylostoma caninum
b. toxocara canis
c. dirofilaria immitis
2
Q
Which of the following have the ability to affect wildlife?
a. echinococcus multilocularis
b. toxoplasma gondii
c. babesia canis
d. trichinella nativa
A
a. echinococcus multilocularis
b. toxoplasma gondii
d. trichinella nativa
3
Q
What is the definitive host for angiostrongylus cantonensis?
a. cat
b. rat
c. fox
d. pig
A
b. rat
4
Q
What is the definitive host for baylisascaris procyonis?
a. fox
b. squirrel
c. raccoon
d. skunk
A
c. raccoon
5
Q
How do humans acquire toxoplasma gondii infections?
A
Through exposure to oocysts (contaminated soil, contaminated tap water, rivers and oceans with runoff containing oocysts, handling wildlife or zoo animals)
or
Through exposure to tissue cysts (white-tailed deer, black bears, necropsy, handling aborted fetuses or placental membranes)
6
Q
T/F: cats of the definitive host for toxoplasma gondii, but any warmblooded wildlife species can carry tissue cysts and infect humans
A
true
7
Q
How do humans get infected with the zoonotic coccidian species, cryptosporidium parvum?
A
ingestion of oocysts (because they are infective when passed in feces)
oocysts can be in soil, water, and filter-feeding shellfish.
8
Q
What protozoan parasite causes “beaver fever” and has many assemblages.
A
giardia duodenalis
9
Q
How do we test for giardia duodenalis?
A
SNAP test – detects antigen
10
Q
describe the appearance of echinococcus multilocularis
A
tapeworm with 3 segments
very small adults (only 3-6 mm)
11
Q
T/F: one echinococcus multilocularis egg can produce MANY adults
A
true
12
Q
How do humans obtain echinococcus multilocularis infections and what disease does it produce?
A
egg ingestion from environment
produces human alveolar echinococcus, which can take 10-15 years between exposure and development of clinical symptoms.
13
Q
what is the definitive host for echinococcus multilocularis?
A
canids
14
Q
Why is diagnosis of echinococcus multilocularis difficult in dogs? What is the BEST way to diagnose?
A
the segments are very small and are rarely seen
flotation might be negative because the eggs are heavy
eggs are indistinguishable from other taeniid eggs
best way to diagnose = PCR
15
Q
how can you disinfect against echinococcus multilocularis?
A
- freezing (-80 C) for days
- undiluted bleach for hours
- flame
16
Q
T/F: echinococcus multilocularis is only found in Canada, Alaska, and Central + Eastern Europe.
A
false – yes in those areas, but it was also detected in northern midwestern states and eastern US (VA, MD, PA, VT)
17
Q
What preventative is successful in treating/preventing echinococcus multilocularis?
A
praziquantel
18
Q
T/F: if a dog presents to your clinic with an abdominal mass, echinococcus multilocularis should be on your differential list.
A
true
19
Q
what human diseases does baylisacaris procyonis cause?
A
visceral and ocular larva migrans
20
Q
How do humans get baylisascaris procyonis infections?
A
raccoons defecate in communal “latrines” which have TONS of eggs.
rodents walk through these latrines and get tons of eggs all over their feet.
rodents then transfer these eggs into the human environment and humans ingest the eggs.
21
Q
Unlike toxocara, baylisascars larvae do what in the human body?
A
continue to grow!
they cause lots of tissue damage and severe acute eosinophilic meningoencephalitis
22
Q
T/F: humans infected with baylisascaris procyonis are never subclinical, the infections are always severe.
A
false – some are subclinical
23
Q
how can you control baylisascaris procyonis?
A
- treat captive raccoons (pyrantel, ivermectin/moxidectin, albendazole/fenbendazole)
- remove racooon feces
- disinfect (flaming the area kills eggs)
24
Q
An IDEXX antigen test can help you determine coprophagy (just passing eggs) from actual adult worm antigen (parasites within the small intestine) in dogs who can carry eggs in their feces and infection is uncommon.
What are the results for each situation?
A
coprophagy - negative antigen test
adult worms in SI – positive antigen test
25
which eggs are larger - toxocara or baylisascaris?
toxocara
26
_________ is a nematode of the small intestine of warmblooded animals. The larvae produced become encysted in the muscle and are transmitted by carnivory or scavenging or ingestion of undercooked meat.
trichenella
27
This parasite is transmitted by a snail. It gets within the pulmonary arteries and right ventricles of rodents (mostly rats).
angiostrongylus cantonensis
28
how can humans get infected with angiostrongylus cantonensis that causes severe eosinophilic meningoecephalitis?
ingestion of snail or larvae (L3)
29
Where is angiostrongylus cantonensis found geographically?
asia, caribbean, hawaii, and southeastern US (FL)
30
What is the primary reservoir for hantavirus (a bunyavirus found in western USA)?
rodents (deer mouse, cotton rat, and white-footed mouse)
31
how is hantavirus transmitted to humans?
virus particles become aerosolized from rodent urine, feces, or saliva and are inhaled
or
through handling rodents
32
T/F: there are generally no clinical signs associated with hantavirus in mice or rats, but humans experience fever, nausea, vomiting, and cough that progressed to acute respiratory disease, DIC, and even death.
true
33
how do we control hantavirus spreading?
rodent control
sanitation
protective equipment (gloves, air-purifiers, disinfection, proper carcass disposal)
34
What is the etiology of the disease Tularemia?
francisella tularensis
35
What is unique about the hosts for tularemia?
there are 2 different cycles
1. terrestrial cycle -- rabbits and rodents
2. aquatic cycle -- muskrats and beavers
36
how is tularemia transmitted?
blood-sucking arthropods
ingestion
inhalation
direct contact
contamination of wounds
37
What area of the US is tularemia most prevalent in?
central US
38
There are many types of clinical signs seen in humans with tularemia and animals get white lesion in liver, spleen, and pneumonia.
To reduce the risk of infection, how can we control tularemia?
sanitary precautions
wear gloves
control insect vectors
39
What is the etiology for plague?
Yersinia pestis (a gram negative bacteria)
40
What/Who is the host for plague?
this pathogen is maintained in nature through a flea-rodent cycle
reservoir hosts = voles, grasshopper mice, rock squirrels
epizootic rodent hosts = prairie dogs, ground squirrels
non-rodent hosts = felids, black-footed ferret
41
What is the mode of transmission of plague?
flea bite
the bacteria multiplies within the fleas GI tract, blocks it, and leads to regurgitation of the infected blood into the host.
42
where in the US are cases of plague more prevalent?
southwestern US (4 corners area)
43
T/F: Plague has a 50% fatality rate in untreated cases
true
44
What is biggest sign that plague is occurring within a certain population or area?
rapid decline of colonial rodents
45
how can you make a definitive diagnosis of plague?
immunohistochemistry (LN, blood, spleen, liver, lung)
46
how can we effectively manage plague infections?
- treatment of the environment to kill fleas
- local control of rodents close to human habitation
- treat pets for fleas (esp. cats)
47
What mycobacterium is a problem in northern deer populations?
mycobacterium bovis
48
how is M. bovis transmitted?
aerosols
consumption of contaminated feed
close contact with infected individuals or contaminated areas
crowding + stress
49
What are the possible sources of maintenance and spread of M. bovis into deer populations?
high deer population density and supplemental feeding
50
T/F: M. bovis is only found in cattle
false -- it spilled over into deer, elk, and non-cervids (cats, dogs, coyotes, bears, raccoons, etc.)
51
You do a necropsy on a dead deer that came from near a dairy farm in michigan. You find many yellow pea-sized nodules all within the chest cavity. There are also swollen lymph nodes. What is most likely your presumptive diagnosis?
tuberculosis -- M. bovis
52
how can you test living animals for tuberculosis?
caudal fold tuberculin test
if its positive, call the state vet and have them do a comparative cervical test.
53
how can we manage tuberculosis?
-reduce deer density
-do not supplemental feed or bait deer
54
Why are we concerned with reducing tuberculosis infections? (2 reasons)
- loss of bovine TB free status and trade
- public health concern
55
what agent causes tuberculosis in birds?
mycobacterium avium (a gram positive acid-fast bacteria)
56
how can we diagnose avian tuberculosis?
culture, PCR, histopathology
post-mortem testing is better
57
What arthropod virus (transmitted by mosquitoes) causes encephalitis in wildlife?
west nile virus
58
We know that the west nile virus is passed between birds and mosquitoes. Who are the dead end hosts of west nile virus?
horses
people
59
What was the source of rapid dissemination of west nile virus from eastern US to the west coast?
bird migratory patterns
60
how do you diagnose west nile virus?
serology or PCR
61
how can we work towards preventing west nile virus?
- insect repellent
- environmental larvicides and adulticides
- vaccinate animals (ex. horses)
62
is WNV zoonotic?
yes
63
What are the 4 reasons wildlife diseases are important?
1. threat to native wildlife populations
2. impact on domestic animals
3. zoonotic potential
4. economic importance
64
What type of virus is rabies?
single-stranded RNA virus in family Rhabdoviridae, genus lyssavirus
65
who can become infected with rabies?
all mammals are susceptible
the wildlife reservoirs are carnivores and omnivores
66
what animal is responsible for the highest # of cases of rabies in VA?
a. raccoons
b. skunks
c. foxes
d. bats
e. rodents
f. domestic animals
a. raccoons
67
what is the difference between dumb rabies and furious rabies?
dumb -- aimless wandering, incoordination, loss of awareness, paralysis
furious -- attacks and self mutilation
both end in convulsions, coma, and death
68
how is rabies transmitted?
direct contact with saliva or nervous tissue of infected animal
aerosol transmission
organ transplant
then it travels from site of entry to the CNS within axons of peripheral nerves
69
how do you diagnose rabies?
post mortem examination of brain tissue
Fluorescent antibody test (FAT)
histopathology shoes encephalitis and negri bodies
70
is rabies reportable?
yes
71
how can we control rabies?
- rabies vaccine for domestic animals (buffer)
- oral rabies vaccine bait for free-ranging carnivores (prevent westward spread)
72
what type of virus is canine distemper?
genus morbillivirus
family paramyxoviridae
enveloped RNA virus
73
what type of cells does canine distemper virus attack?
epithelial cells of resp tract, GI tract, and eyes
74
what are *key* clinical signs of canine distemper virus?
respiratory signs (dyspnea, cough, sneeze), diarrhea, neurological signs, hyperkeratosis of foot pads
75
what is the transmission for canine distemper virus?
direct contract or aerosol of ocular and nasal secretions + urine
76
can you treat canine distemper virus in infected wildlife?
no
77
how can you definitively diagnose canine distemper virus? (3 potential ways)
1. histpathology -- intranuclear and intracytoplasmic inclusions
2. virus isolation from discharge
3. FAT -- ocular swab
78
is canine distemper a major public health concern?
no
79
what is one of the most important infectious diseases of white tailed deer in southeastern US?
hemorrhagic disease
80
what is the etiology of hemorrhagic disease?
2 closely related orbiviruses -- epizootic hemorrhagic disease (EHD) and bluetongue virus
81
how quickly do wildlife die once infected with hemorrhagic disease?
1-3 days
animals are often found dead near a source of water
82
what is the transmission of hemorrhagic disease?
biting midges
occurs mostly in late summer/early fall.
83
what area of virginia has the highest prevelance of hemorrhagic disease?
east coast
84
T/F: hemorrhagic disease is a severe public health risk
false -- no public health significance
85
What pathology does chronic wasting disease cause?
progressive neurological disease resulting in death
86
What group of diseases does chronic wasting disease belong to?
transmissable spongiform encephalopathies
these are diseases caused by abnormally shaped proteins called prions that accumulate in neurons and result in degeneration of the CNS
(BSE, scrapie, CJD, and transmissable mink encephalopathy)
87
what species are affected by CWD?
white-tailed deer
elk
mule deer
black-tailed deer
moose
88
what is the most important mode of transmission for CWD?
animal to animal
other: indirect transmission from contaminated food or envionrment
89
how do you diagnose CWD?
postmortem examination of the obex of medulla oblongata and retropharyngeal lymph nodes for the presence of prions
ELISA test for free-range white tailed deer
90
is CWD transmissable to humans?
not currently
91
what disease in bats is caused by fungus, Pseudogymnoascus destructans that likes cooler temperatures?
white-nosed syndrome of bats
92
T/F: Pseudogymnoascus destructans is responsible for killing millions of bats
true
93
what is the pathogenesis of Pseudogymnoascus destructans in white-nosed syndrome in bats?
the fungus is irritating and they are unable to hibernate ,so they stay awake. This increases there metabolism and they lose weight. As a result, they come out of hibernation earlier.
94
how do we treat and control white-nosed syndrome in bats?
no known successful treatment or control
95
what emerging disease is caused by a lagovirus that was identified in adult domestic rabbits in FL first, but now has been identified in adult wild rabbits in SW US.
rabbit hemorrhagic disease (RHDV1)
96
which rabbit hemorrhagic disease has lower mortality -- 1 or 2?
RHDV2
97
T/F: treatment for rabbit hemorrhagic disease is unrewarding, but there are vaccines available in europe and australia.
true
98
T/F: SARS-CoV-2 has been reported in numerous species
true
99
what is the difference between dry and wet avian pox?
dry -- proliferative nodules on unfeathered body (feet, beak)
wet -- raised plaques in mouth and resp tract
100
what is the transmission of avian pox?
blood feeding insects
inhalation
ingestion
101
how do you diagnose avian pox?
histpathology
viral isolation
PCR
102
how can we control avian pox?
- eliminate mosquito breeding sites
- use repellents and env. pesticides
- disinfect equipment (in captive)
- give MLVs (domestic birds)
103
is avian pox transmissable to humans?
no
104
what is the etiology of duck plague or duck viral enteritis?
herpesvirus
105
how is duck plague transmitted?
contact with infected waterfowl or environment
106
if a duck has bloody discharge from nose, mouth, and vent, as well as prolapsed phallus and is unable to fly, what is the most likely presumptive diagnosis?
duck plague
107
what season is duck plague most prevalent in?
late spring
108
how do you diagnose duck plague?
virus isolate
serology
109
how can we control duck plague?
destroy infected flocks and eggs
carcass disposal
decontaminate environment
110
is there a vaccine approved for domestic ducks against duck plague?
yes
111
is duck plague transmissable to humans?
no
112
what type of virus causes avian influenza?
orthomyxovirus
113
T/F: avian infleunza generally does not cause clinical disease in domestic birds, only wild birds
false -- opposite. it ~generally~ does not cause clinical problems in wild birds.
114
which avian influenza types are the most common high pathogenic types?
H5 and H7
115
T/F: both HPAI and LPAI are reportable diseases
false -- only HPAI
116
what is the transmission of avian infleunza?
horizontal
migratory waterfowl are reservoirs
virus is shed in feces and secretions, contaminated feed, water, equipment, vehicles, and people.
117
T/F: the incubation period for avian influenza is very short (hours-days)
true
118
how do you definitively diagnose avian influenza?
serology
virus isolation
119
is avian influenza transmissable to humans?
yes -- HPAI has been directly transmitted between birds and people.
120
what is the etiologic agent of avian cholera?
pasteurella multocida
121
what is the transmission of avian cholera?
infected birds shed the bacteria
infected carcasses
chronic carriers
122
what season is avian cholera most prevalent in?
winter
123
T/F: avian cholera is associated with water birds, but there is also a rodent cycle
true
124
what 2 areas of the US is avian cholera most prevalent in?
pacific flyway
mississippi/central flyway
125
T/F: avian cholera causes hemorrhage of the heart, gizzard, and liver, as well as multifocal necrosis of the liver.
true
126
how do you definitively diagnose avian cholera?
bacterial culture
127
how can we control avian cholera infections?
- disposal and incineration of infected carcasses
- habitat management
- disinfection
- vaccinate captive flocks
128
does avian cholera have a high public health risk?
low risk of disease
129
salmonella is normal flora in what species?
mostly pet turtle and iguanas, but also birds and dogs.
130
What is the transmission for salmonella typhimurium?
fecal oral
inhalation of vacuum dust
131
what are the symptoms of salmonella typhimurium?
GI signs
but they are self-limiting
132
how can we control salmonella infections from wildlife to humans?
- inform owners when purchasing reptiles
- wash hands
- avoid contact with reptiles if young or immunocompromised
- keep out of households with children <5y
- do not allow reptiles to roam freely in house
- keep reptiles out of kitchens and food prep areas (do not use kitchen sink to bathe reptiles or wash them)
133
how do humans acquire Plague (yersinia pestis)?
flea bites
abrasions in skin or bite from infected animal
infected cats with draining abscesses or pnuemonia
direct contact or aerosol
134
What are the symptoms of Plague in humans?
vesicular lesion at site of flea bite
lymphadenopathy
septicemia
pneumonia
135
how can we control Yersinia pestis infections in humans?
insecticides/rodenticides (fleas and rodents)
proper handling of pneumonic cats or cats with lymphadenopathy
wear gloves and eye protection
136
How can humans acquire Tularemia (francisella tularensis)?
- ticks (ixodes and dermacentor)
- through abrasions in skin
- through conjunctiva
- oral ingestion (cont. water, improperly cooked meat)
- inhalation (dust or wool)
- handling cats with infection
137
What is the most common form of tularemia in humans?
ulceroglandular form
138
what is the most fatal form of tularemia in humans?
pneumonic form
139
what is the treatment for tularemia?
streptomycin or gentamicin
140
how do we prevent tularemia infections in humans?
- necropsy animals with gloves
- properly cook animals
- disinfect water
- insect repellent
141
What is the most reported tick-borne disease in north america?
lyme disease (borrelia burgdorferi)
142
How do humans acquire lyme disease?
bite of ixodes scapularis or pacificus ticks
takes 48 hr for the transfer of the organism
143
What is the most common symptom of lyme disease in humans? How is that different from animals?
erythema chronicum migrans (bullseye rash)
animals get arthritis, lameness, fever, lymphadenopathy, and renal disease
144
what is the treatment for lyme disease?
doxycycline, amoxicillin
145
how can we prevent lyme disease?
1. avoid tick infested areas
2. keep grass short
3. wear light colored clothes
4. tuck pant legs in
5. do tick checks
6. apply tick repellent to body and clothes
146
what organism is responsible for causing rocky mounted spotted fever?
rickettsia rickettsii
147
how is rickettsia rickettsii transmitted?
tick bites (dermacentor, amblyomma, haemaphysalis)
rodents are reservoir
tick must be attached for 5-20 hours for transmission to occur
148
what time of the year is RMSF incidence highest?
mid april through mid september
149
what are the symptoms of RMSF?
fever, chills, headache, muscle pain, macular eruptions of measles
CNS signs that progress to pneumonia
150
The case fatality rate of RMSF is only 5%. What is the treatment for this condition?
tetracyclines
151
how can we prevent RMSF?
insecticides (tick prevention)
152
how do humans acquire hantavirus?
inhalation of aerosolized rodent excretions
153
who are the reservoirs for hantavirus?
deer mice and other rodents shedding it in their feces, urine, and saliva
154
what symptoms does hantavirus cause in humans?
fever, fatigue, chills, myalgia, headache, cough, and progressive bilateral pneumonia and respiratory failure
155
T/F: 75-80% of humans that acquire hantavirus and develop clinical signs die.
false -- 30-50% (thats still a high fatality rate)
156
what can we do to control hantavirus spreading to humans?
-eliminate rodents inside homes
- spray rodent areas with water prior to cleaning to reduce aerosolization
157
What is the agent causing California Encephalitis (LaCross Encephalitis)?
bunyavirus
158
What time of year does california encephalitis mostly occur?
july through end of september
159
what age group of people does california encephalitis affect the most?
children and adolescents
160
how is california encephalitis acquired in humans?
mosquito bites
161
who is the reservoir for california encephalitis?
mosquitoes, chipmunks, and squirrels
162
what are the symptoms of humans with california encephalitis?
mild fever, nausea, diarrhea, and encephalitis
163
what is the fatality rate for california encephalitis?
less than 1%
164
how can we control california encephalitis?
mosquito control
165
What agent causes lymphocytic choriomeningitis?
arenavirus
166
describe the transmission of lymphocytic choriomeningitis to humans?
mice infect hamsters and guinea pigs, which transmit it to humans
or ingestion
167
who is the reservoir for lymphocytic choriomeningitis?
house mouse
168
what are the symptoms of lymphocytic choriomeningitis in humans?
influenza-like symptoms, meningitis, can be fatal (rarely).
169
T/F: mice infected with lymphocytic choriomeningitis do not show signs.
true
170
how can we prevent lymphocytic choriomeningitis in humans?
wear gloves when handling mice
control mouse populations
171
What is the agent for macacine herpesvirus 1?
Herpes B virus
172
how do humans acquire macacine herpesvirus 1/herpesvirus B?
bites or skin abrasions contaminated with monkey saliva
potentially aerosols entering conjunctiva, nose, or pharynx.
173
who is the reservoir for macacine herpesvirus 1/herpesvirus B?
rhesus monkeys
174
T/F: macacine herpesvirus 1/herpesvirus B is a highly fatal disease in humans and those who survive have chronic neurological signs
true
175
T/F: macacine herpesvirus 1/herpesvirus B is highly fatal in animals as well as people
false -- animals show signs that are similar to herpes simplex (cold sores, blisters)
176
how can we prevent macacine herpesvirus 1/herpesvirus B?
- quarantine monkeys for 6-8 weeks
- eliminate monkeys with herpetiform lesions
- house monkeys in small groups to reduce transmission
- wear gloves and protective clothing
- clean bites and scratches
177
what type of virus is monkeypox virus?
orthopoxvirus
178
how is monkeypox transmitted to humans?
contact with infected animals
H-H transmission possible
179
what are the symptoms of monkeypox virus in humans?
vesicular and pustular rash that develops into vesiculation, pustulation, and crusting
fever, headache, non-productive cough
