Term
|
Definition
a host that maintains the infectious
agent of disease in nature and can serve as a source
of infection for humans/domestic animals. |
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Term
|
Definition
any agent such as food, water, or
arthropod that transmits a disease organism (we’ll
focus primarily on arthropod vectors). |
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Term
|
Definition
the chronic level of disease frequency;
that is, a low but constant occurrence of a disease in
a population. |
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Term
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Definition
An outbreak of disease; large numbers of
animals die in a short period. |
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Term
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Definition
| A disease that humans may acquire from animals. |
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Term
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Definition
an intimate heterospecific association,
temporary or permanent, where there exists some metabolic
dependence of one partner, the parasite, on the other
partner, the host. |
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Term
|
Definition
a parasitic worm (flatworm, roundworm,
spiny-headed worm) |
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Term
|
Definition
a parasite that is a member of the
phylum Arthropoda (crustaceans, insects, arachnids). |
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Term
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Definition
a parasite belonging to the ciliate,
flagellate, amoeboid, or apicomplexan groups of the Protozoa. |
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Term
|
Definition
the anatomic or functional manifestations of
disease; an organism that induces pathology is said to be
pathogenic. |
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Term
|
Definition
a form of disease that causes sickness
for short periods of time and the illness if often not detected |
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Term
|
Definition
a form of disease that can last for months, but
if the disease organism is highly virulent, death can occur
in hours. |
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Term
|
Definition
typically a bird (the parasite) that lays
its eggs in the nest of another bird (the host), after which
the host raises the parasite’s young at the expense of its
own offspring. |
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Term
|
Definition
a superfluous host that can be found in
the life cycle of a parasite but within which no further
development of the parasite takes place. |
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Term
|
Definition
| a disturbanceto the normal function or structure of an animal. |
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Term
| wildlife biologists typically work with the influences of disease at the ____________ level. |
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Definition
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Term
|
Definition
a. infectious or non-infectious
b. intrinsic or extrinsic in cause |
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Term
|
Definition
| genetic influences, metabolic/nervous disorders |
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Term
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Definition
| viruses, bacteria, worms, insects |
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Term
|
Definition
A. Infectious
B. Parasitic
C. Toxic/Exogenous
D. Physiological
E. Deficiency/Nutritional
F. Congenital
G. Hereditary
H. Degenerative |
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Term
|
Definition
disease that is communicable from one
organism to another (bacteria, protozoa, viruses,
metazoans) |
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Term
|
Definition
disease that is due to parasitic infection
(protozoan, metazoan) |
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Term
|
Definition
involves poisons/toxins which can act on
organisms in several ways:
1. produce local injury to tissues
2. destruction of epithelial cells in the kidney or
liver after absorption
3. upsetting metabolic/functional activities
4. most commonly, plant poisons affect wildlife |
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Term
|
Definition
involves disease brought on by physiological changes due to severe short term or prolonged stress (trauma)
1.non-lethal but injurious predation can cause trauma to the animal predisposing it to disease.
2. accidents with vehicles do not always result in
death; if the animal survives, there is risk of
secondary infection that could lead to death |
|
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Term
| deficiency/nutritional disease |
|
Definition
disorders of metabolism
caused by:
1. inadequate nutrients in the diet -most common
2. poor quality diet -most common
3. interference with intake (anorexia, mechanical
obstruction)
4. interference with absorption of nutrients
5. interference with storage or use of nutrients
6. increased excretion
7. increased dietary requirements associated with
pregnancy or lactation
8. inhibition of nutrients by inhibitors |
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Term
|
Definition
| disease that exists at birth |
|
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Term
|
Definition
-disease that is passed from parent to offspring
genetically and can be latent
-hereditary defects that interfere with normal
function usually are self-limiting and the individual has
reduced chance of survival. |
|
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Term
|
Definition
-disease that causes a slow “wasting away” of host
-infection is long term/chronic |
|
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Term
| Why study wildlife diseases? |
|
Definition
A.Domestic or wild animals may serve as reservoirsor as vectors for pathogens that ultimately affect each other or humans. (EX: bison brucellosis in Yellowstone that affected ranchers' cattle)
B. With habitat decreasing in many areas, animal populations
are forced into and managed in smaller and smaller areas.
This increase in population densitycauses stress to the
animals, which predisposes them to disease.
C. Disease may cause serious losses in already small
populations of endangered species.
D. Diseases are just as much a part of the mgmt puzzle
as are food habits, population dynamics, habitat
requirements, etc.
E. Disease has a sociological impacton hunters.
F. Disease affects a very important ecological component –
predation. |
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Term
|
Definition
bacterial disease causes infected cattle to suffer
abortions, reduced milk production, infertility, and other
reproductive disorders; it is also a zoonosisin that it can
be transmitted to humans as ungulant fever. |
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Term
| How does disease affect predation? |
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Definition
| diseased organisms are weaker -> results in reduction in the impact of the pathogen -> w/out predation, sick animals not culled out & pathogen assumes more important role |
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Term
Q. What are some other reasons why managers, who are not
pathologists,should have a basic knowledge about diseases? |
|
Definition
1. He/she can help the pathologist
2. Chance to enhance his/her employer/agency
3. Health of habitat can be monitored
4. Detection of zoonoses
5. Severity of disease
6. Impact on economy |
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Term
| Factors affecting disease: |
|
Definition
1. habitat
2. pop density
3. biology of the animal affected
4. biology of the pathogen
5. activity by humans
6. presence of vectors
7. time of the yr and weather |
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Term
| Factors affecting disease (habitat) |
|
Definition
ecological conditions involving habitat quality
and quantityare associated with disease. Disease can
involve several components of the ecosystem including
invertebrates and soil conditions.
EXAMPLE: Fasciola hepatica(sheep/cattle liver fluke) |
|
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Term
| EXAMPLE (habitat factor): Fasciola hepatica(sheep/cattle liver fluke) |
|
Definition
-Flukes utilize snails as a first intermediate host.
-Snails require shallow surface water & they estivate when there is no water.
-Ideal habitat is heavy clay soil that limits water drainage; snails are absent from sandy soils where surface water drains rapidly. Therefore, sheep/cattle grazing on sandy soils remain largely free of this parasite, but sheep/cattle grazing in heavy clay soil pastures are constantly exposed to infection. |
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Term
| factors affecting disease (population density) |
|
Definition
density-dependent responses of
diseaseobserved often where the greater the number of
animals, the larger the number exposed to parasitesand
the larger numbers of parasites produced.
EX: Red grouse (Lagopus lagopus scoticus) infected w/ nematode Trichostrongylus tenuis |
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Term
| Example (pop desnity): Red grouse infected w/ nematode Trichostrongylus |
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Definition
-Nematode larvae will climb to the top of grass-Ingested by red grouse, inside of which they develop into adults
-Eggs pass out of host in the feces to molt/re-& infect.
-The denser the grouse population, the greater the
proportion of “infected” grass tips, thus increasing the
number of parasites taken in by the bird during feeding |
|
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Term
| factors affecting disease (biology of the animal affected): |
|
Definition
state of health as wellas feeding, reproductive, and behavioral habits of animalsaffect susceptibility, can expose animals to disease, and promote its spread.
EXAMPLE: mourning doves are infected with a protozoan
Trichomonas gallinae |
|
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Term
| Example (biology of animal affected): mourning doves infected w/ protozoan Trichomonas gallinae |
|
Definition
attacks the upper digestive
track causing lesions.
-The disease is spread by the feeding behavior of
parents to young: nestlings are fed regurgitated “crop
milk” from their infected parents.
-Among adults, parasite
is transmitted when birds
that cannot swallow food due
to the lesions in their throats
drop the now-contaminated
seeds & other birds feed
on them. |
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Term
| Factors affecting disease (biology of the pathogen) |
|
Definition
a pathogen might infect 2 or more species of hosts, but the pathology incurred by the parasite might be significantly more apparent in one host than in another.
EXAMPLE: The nematode Parelaphostrongylus teniusinfects both deer and moose. |
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Term
| Example (biology of the pathogen): The nematode Parelaphostrongylus tenius in deer & moose |
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Definition
| teniusinfects both deer and moose. -The adults are found in the meninges of the brain. In deer, these worms cause little damage but in moose they severely damage the central nervous system, causing paralysis and death. -Thus, the same parasite is essentially harmless in deer but in moose produces a fatal disease known as blind staggersor moose sickness. -As expected, in areas where deer and moose populations overlap, if high numbers of deer are infected, high mortality is seen within moose populations. |
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Term
| Factors affecting disease (activity by humans) |
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Definition
| treatments(antihelminthics, etc), hunting(reducing numbers of diseased animals in populations) and possible exposure to disease via reintroduction of animal species into areas.***Also introduction of new hosts/exotics:EXAMPLE: introduction of night-flying mosquito (Culex pipiens) into Hawaii |
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Term
| EXAMPLE (activity by humans): intro of night-flying mosquito (Culex pipiens) into Hawaii |
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Definition
| caused havoc to the endemic birds of Hawaii. This mosquito is a vector for avian malaria (Plasmodiumsp). |
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Term
| Factors affecting disease (presence of vectors) |
|
Definition
vectors are important carriers of
disease, and if the geographic range of the vectors
coincides with that of the host, then epizootics are possible.
This geographic rangecan be either horizontal(e.g., along
a shoreline or edge of a pond) or vertical(e.g., distances
less than 2 m above the surface)
EXAMPLE: a species of blackfly (Simulium rugglesi) is the
vector for the malarial parasite Leuocytozoon simondi,
which infects waterfowl. |
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Term
| EXAMPLE (presence of vectors): blackfly (Simulium rugglesi) is vector for malarial parasite Leuocytozoon simondi which infects waterfowel |
|
Definition
-The blackfly’s horizontal geographic range covers
much of the breeding range for ducks and geese in N.
America.
-Waterfowl are also a natural reservoir for the
parasite helping its spread to blackflies
during nesting periods, when it’s easier for blackflies to obtain a bloodmeal from the nesting birds. |
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Term
| Factors affecting disease (time of yr & weather): |
|
Definition
thetime of the year
(seasonality) and weather (rainy or excessively hot/dry)
can also influence disease. |
|
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Term
| EXAMPLE (time of yr & weather): the mystery of EHD |
|
Definition
BACKGROUND: Epizootic hemorrhagic disease/virusinfects white-tailed deer, where mortality rates can be as high as 90% in infected animals. -Symptoms are internal hemorrhaging, loss of appetite, weakness, and eventual death within 3-36 hrs of exposure. -Known outbreaks of EHD occur in August, September, and October but terminate abruptly with the first frost. -Long periods of excessively hot, dry weather precede epizootics
Q: WHAT DO YOU THINK IS GOING ON?
The disease is utilizing an arthropod vector, specifically
midges of the genus Culicoides.
-These midges prefer hotter, dryer weather and
numbers increase causing disease prevalence among deer
populations to rise significantly |
|
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Term
| Diseases can be used as agents to control _________ |
|
Definition
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Term
| EXAMPLE (disease as agent to control exotics) MYXOMATOSIS VIRUS |
|
Definition
MYXOMATOSIS VIRUS:
-European rabbit was introduced into Australia in
1859 & spread across the continent in only 16 years.
-Explosion of rabbits led to widespread overgrazing,
wind, and water erosion of soil. Conflicts with sheep
industry resulted as rabbits consumed all sheep forage.
-Fences, poisons, etc. were tried but nothing worked.
-1950: mammalian pox virus myxomatosis introduced into
population (virus very virulent in European rabbits but not
to marsupials and other domestics).
-Disease is spread by mosquitoes, and it reduced the
numbers of rabbits to 10-20% of original numbers by 1970's.
-Some rabbits developed resistance and numbers have
rebounded back to ~300 million by 1996. |
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Term
| ________ can be used to control disease |
|
Definition
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Term
| EXAMPLE (vectors used to control disease): BLUETONGUE |
|
Definition
BLUETONGUE:
-The main host is the desert bighorn sheep as well as
deer, pronghorns, elk, sheep and goats.
-This disease causes inflammation of the mucosal
membranes of the GI tract, especially the mouth and nose
causing discoloration (blueing) of the tongue.
-Culicoides varipennisis the arthopod vector of virus.
-It has been proposed (Robinson et al., 1974) that these
could be used as “mobile syringes” to immunize bighorn sheep.
By giving the insects a bloodmeal that includes bluetongue
vaccine they can then be released to seek out and vaccinate
animals that otherwise couldn’t be approached by humans. |
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Term
| Q. What is wrong with this idea of using Culicoidesspp as a vaccinizing vector? |
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Definition
| For deer, it is this same group of arthropods that carryepizootic hemorrhagic disease. So you might be treating one disease in deer affected, but in effect also increasing the potential of another disease to wipe out the population. |
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Term
| Bacterial Diseases of Migratory Birds |
|
Definition
A. Avian Cholera
B. Avian Botulism |
|
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Term
|
Definition
CAUSE: caused by bacterium Pasteurella multocida
EFFECT: acute infections can cause death in 6-12 hrs, killing 1000+ birds a day; death so quick some birds die in flight.
TRANSMISSION: bird-to-bird contact, ingestion of contaminated food & water, & inhaled in aerosol form
SYMPTOMS:
1. lethargy, not afraid of humans
2. bird will die quickly (sec/min) of handling
3. convulsions, erratic flight
4. soiling/mattiing of feathers near vent, eyes, & bill
5. prominent lesions on heart, liver, & gizzard
CONTROL/MGMT: collection/incineration of carcasses; prevent use of specific wetlands that are focal points of infection; add water to problem areas to dilute concentrations of P. multocida |
|
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Term
|
Definition
CAUSE: ingestion of toxin produced by the bacterium CLostridium botulinum. 7 types/strains of botulinum affecting diff birds.
EFFECT: lethal; annual losses can exceed 50,000 birds in single location; 4-5,000,000 birds died in western US in 1952!
TRANSMISSION: combo of toxin produced by bacteria in dead birds, maggots in dead bird carcasses, & "healthy" birds that ingest maggots. enivonmental factors include high ambient temps & water quality (occurs more in summer)
SYMPTOMS:
1. 1. Lines of carcasses
2. Botulism-affected birds tend to congregate along
vegetated peninsulas and islands
3. Paralysis of voluntary muscles, nictitating membrane,
and neck muscles.
4. Ability to fly is lost
5. At this point, birds typically dies from drowning
(loss of neck muscle control); therefore, lesions associated
with drowning are observed at necropsy.
CONTROL/MGMT: watch for areas of abundant flies & animal carcasses to stop new infections; promt removal of carcasses; sick birds fed freshwater & antitoxin; give birds shade |
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Term
| Viral Disease of Migratory Birds |
|
Definition
|
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Term
|
Definition
CAUSE: herpes virus & affects ducks, geese, & swans
EFFECT: often fatal
TRANSMISSION: some birds are carriers; outbreaks from virus shedding by carrier birds to susceptible ones
SYMPTOMS:
1. no prolonged illness
2. sick birds exhibit hypersensitivity to light
3. droopiness, thirst, and bloody discharge from vent/bill
4.internal hemorrhaging in GI tract
CONTROL/MGMT: difficult; do not release birds or eggs from flocks w/ history of the disease |
|
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Term
| Fungal Disease of Migratory Birds |
|
Definition
|
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Term
|
Definition
CAUSE: fugi genus Aspergillus
EFFECT: causes infection of the respiratory tract
TRANSMISSION: not contagious; inhalation of A. spores. outbreaks in fall-early winter after hunting season. birds w/ deficient diets/immune systems more susceptible
SYMPTOMS:
1. emaciation
2. difficulty breathing
3. if infection reaches brain, loss of muscular coordination
4. gross lesions in lungs and air sacs
CONTROL/MGMT: maintain clean environment |
|
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Term
| Parasitic Diseases of Migratory Birds |
|
Definition
A. Gizzard worms
B. Nasal Leeches
C. Brown-headed cowbirds |
|
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Term
|
Definition
CAUSE: nematode (roundworm) species like the spiurid CHeilospirura hamulosa located b/t surface lining & grinding pads of gizzard
EFFECT: not fatal
TRANSMISSION: ingestion of infective gizzard worm larvae
SYMPTOMS:
1. no obvious signs
2. in necropsy, sloughing, inflammation, hemorrhages, and ulceration of gizzard lining erode grinding pads of gizzard.
CONTROL/MGMT: look for gizzard worm eggs in feces and/or eval of carcasses. |
|
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Term
|
Definition
CAUSE: bloodsucking leeches of genus Theromyzon
EFFECT: mild irritation; severe infections cause blindness, eye damage, blocked nasal passages, throat blockage, or blocked trachea
TRANSMISSION: peak parasitism in spring & summer
SYMPTOMS:
1. infected birds are irritated and can be seen
trying to remove them
2. labored breathing and gasping
CONTROL/MGMT: no control measures; biologists/managers can see blood-engorged leeches protruding from nares or attached to eyes |
|
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Term
|
Definition
| CAUSE: Kirtland's warblers parasitized by brown-headed cowbirds, which are obligate brood parasites EFFECT: lowers # of host's young that survive b/c they're caring for parasitic young TRANSMISSION: cowbirds don't build own nest, lay their eggs among clutches of other nesting birds SYMPTOMS: 1. bird(s) in nest that do not look like parent bird, but look strangely like cowbirds? 2. broken eggs below nest; mother cowbird will remove some, not all, of the host’s eggs. CONTROL/MGMT: cowbirds prefer patchy forests - managers avoid fragmentation of forest; wire traps baited w/ sunflower seeds & live decoys[image] |
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Term
| Toxic Diseases of Migratory Birds |
|
Definition
A. Lead Poisoning
B. Oil Toxicosis |
|
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Term
|
Definition
CAUSE: absorption of hazardous levels of lead into body tissues
EFFECT: eventually fatal
TRANSMISSION: by hunters/fishers or industry
SYMPTOMS:
1. reluctance to fly
2. if fly, weakness and inability to sustain flight
3. develop wing drop
4 emaciation
5. wasting away of breast muscle, impacted esophagus/proventriculus, distended gall bladder
CONTROL/MGMT: denying bird use in problem areas, removal of dead birds, use of nontoxic shot on hunting areas |
|
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Term
|
Definition
CAUSE: exposure to spilled petroleum products
EFFECT: hypothermia & poisoning from ingestion, inhalation, or absorption of the product
TRANSMISSION: human-caused oil spills; most spills occur in winter when navigation difficult
SYMPTOMS:
1. bird is wet and chilled because oil damages feather waterproofing and insulation.
2. thin, because they stop feeding and use fat reserves and muscle to produce heat in response to chilling
3. oil may be in trachea, lungs, GI tract,and near vent
4. intestine is reddened
5. salt glands swollen and adrenal glands become enlarged
CONTROL/MGMT: identification obvious; control expensive & complicated |
|
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Term
| Bacterial Diseases of Mammals |
|
Definition
A. Tuberculosis
B. Brucellosis
C. Anthrax |
|
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Term
|
Definition
CAUSE: bacterium Mycobacteria
EFFECT: deer & cattle, evidenced by tubercles which form as body attempts to wall off infection (fatal)
TRANSMISSION: bacteria shed into exhaled air, body fluids, & exudate from tuberculosis abscesses...then enter lymph notes to replicate
SYMPTOMS:
1. chronic cough
2. emaciation
3. anorexia
4. low grade fever
CONTROL/MGMT: zoonosis; screen pops by dermal sensitivity testing. mgmt difficult - test/slaughter; carcasses incinerated |
|
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Term
|
Definition
CAUSE: bacteria of Brucella spp. & infects cattle, elk, bison, reindeer, sheep, goats, & wild pigs
EFFECT: high fever, joint disease, abortion, damage to reproductive system, death
TRANSMISSION: oral route & bacterial localize in organs/joints & reproductive system
SYMPTOMS:
1. abortion, premature birth, neonatal mortality
2. lameness and joint infections
3. swollen lymph nodes
4. at necropsy, legions of varying degrees of severity observed in different host spp.
CONTROL/MGMT: zoonosis; keep infected cattle off open ranges; herds culled & vaccinated; testing before shipment |
|
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Term
|
Definition
CAUSE: bacteria Bacillus anthracis & affects ruminants, humans & other animals
EFFECT: fatal
TRANSMISSION: neutral or alkaline soils; decomposing vegetation following flooding; inhalation/inoculation; biting insects
SYMPTOMS:
1. aggressiveness
2. agitation
3. depression
4. body fluid leaking from rectum, nose, mouth
5. edema and hemorrhaging
CONTROL/MGMT: zoonosis; very contagious to man; vaccine available; carcasses burned |
|
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Term
| Viral Diseases of Mammals |
|
Definition
A. Hemorrhagic Disease
B. Foot-and-Mouth Disease
C. Rabies
D. Mad Cow Disease |
|
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Term
| Hemorrhagic Disease (Bluetongue & Epizootic Hemorrhagic Disease) |
|
Definition
CAUSE: viral, 4 serotypes of BT & 2 of EHD
EFFECT: variety of livestock & wild ungulates, less severe-fatal
TRANSMISSION: biting midges or gnats (Culicoides spp); prevalent in warmer months; cattle=reservoir hosts
SYMPTOMS:
Acute/fatal cases:
1. depression & very thirsty
2. appear to be blind
3. swollen ears, eye lids, lips and tongue
4. froth exuding from nostrils
5. hemorrhaging
6. dead hosts around water holes (see 1)
Less severe cases:
1. ulcers in mouth
2. tongue may be dark/ulcerated
3. abortion/neonatal death occurs
4. animals with less severe cases can survive but remain emaciated
CONTROL/MGMT: no good treatment; steeply sloped ponds=reducing organic content of water=less gnat breeding |
|
|
Term
| Q. This strategy of keeping ponds steeply sloped is also used to control disease in cultured freshwater catfish ponds. What disease in catfish do you think farmers are trying to control for by doing this? |
|
Definition
| [image]Infection by digenetic trematodes (diplostomes). REMEMBER: flukes use snails as first intermediate hosts. By keeping the edges of ponds steep, the snails are cut down on the edges of the pond, thus helping to control fordigenetic trematodes. |
|
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Term
|
Definition
CAUSE: picornavirus of the genus Aphthovirus & affects many spp of cloven-hoofed animals
EFFECT: blisters rupture & transmit virus, ulcerations & secondary infections, damage heart, death; some survive but become carriers
TRANSMISSION: extremely infectious, shed in oral secretions; survives in manure, blood & excreta; aerosol transmissions
SYMPTOMS:
1. depression
2. loss of appetite
3. emaciation
4. lame
5. profuse salivation
6. blisters/vesicles on legs/feet & nose, & near mouth
CONTROL/MGMT: no treatment; infected are quarantined, tested, & slaughtered |
|
|
Term
|
Definition
CAUSE: Rhabdovirus (bullet-shaped viruses) of genus Lyssavirus
EFFECT: virtually 100% fatal; must be treated immediately in humans or fatal; pathogen attacks brain & spinal cord
TRANSMISSION: salivary glands of infected animals (bats, raccoons, skunks, foxes, dogs, cats, etc.) when it bites
SYMPTOMS:
Wildlife: 1) furious form - "mad-dog"; 2) paralytic (dumb) form
Man: thirsty, convulse & terrified of water; by time of symptoms, it's too late
CONTROL/MGMT: zoonosis; dangerous in urban areas (raccoons, dogs, & cats); all dogs require vaccination; isolate/sacrifice wildlife w/ symptoms |
|
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Term
| Mad Cow Disease (Bovine Spongiform Encephalopathy) |
|
Definition
CAUSE: "prion" - infectious protein lacking nucleic acid; damage nearby healthy cellular proteins; found in cattle; scrabie is a form in sheep & chronic wasting disease is a form in deer; Creutzfeldt-Jacob disease may be this in humans.
EFFECT: death
TRANSMISSION: feed produced from infected animals; mother to calf (maybe); humans believed to be infected by ingesting beef
SYMPTOMS:
1. belligerence
2. confusion
3. poor coordination
4. increased thirst/urination
5. destruction of nerve cells in brain - sponge-like appearance
CONTROL/MGMT: zoonosis; no treatment; infected animals isolated/slaughtered |
|
|
Term
| Parasitic Diseases of Mammals |
|
Definition
A. Gastrointestinal nematodes
B. Liver flukes
C. Arthropods |
|
|
Term
| Gastrointestinal nematodes |
|
Definition
CAUSE: several general of nematodes (e.g. Ostertagia, Haemonchus)
EFFECT: minimal, unless heavy infection
TRANSMISSION: eggs deposited in feces, larvae hatch, & eaten by host w/ grass
SYMPTOMS:
1. diarrhea
2. weight loss
3. anemia
CONTROL/MGMT: preventive; new animals have fecal exams & treatment w/ antihelminthics before release |
|
|
Term
|
Definition
CAUSE: spp of digenean genera Fasciola & Fascioloides
EFFECT: minimal, unless heavy infection
TRANSMISSION: accidental ingestion of infective stages on vegetation
SYMPTOMS:
1. weight loss
2. diarrhea
3. anemia
CONTROL/MGMT: preventive; new animals have fecal exams & treatment w/ antihelminthics before release; have sheep & cattle graze on sandy soil & not snail habitat |
|
|
Term
|
Definition
CAUSE: ticks, flies, gnats, mites, fleas
EFFECT: variety of disease
TRANSMISSION: mobile or act as vectors for other diseases
SYMPTOMS: varies w/ disease & arthropod
CONTROL/MGMT: zoonosis; dipping of animal to ride it of arthropod or depop of known hosts |
|
|
Term
| Wildlife Diseases Affecting Man (Zoonoses) |
|
Definition
1. Lyme Disease
2. Bubonic Plague/Black Death
3. Sylvatic plague
4. Tularemia
5. Rabies
6. Helminths: beef tapeworm(Taenia) |
|
|
Term
|
Definition
-most common arthropod-borne disease of
humans in U.S.
-pathogen is a spirochete bacterium
(Borrelia burgdorferi)
-vector transmitted by larvae, nymph, and adult stages of the deer tick (Ixodes spp).
-higher prevalence seen in hunter, hikers, and other venturing in woodlands
-symptoms include arthritis, abnormal heart rhythm,and neurological difficulties. Classic symptom is the bulls-eye rash.
-treatment is by antibiotics |
|
|
Term
| Bubonic plague/Black Death |
|
Definition
-wiped out 1/3 of the population of Western Europe in 14th century (20 million people)
-caused by the bacteria Yersinia pestis (2 part“safety pin” appearance)
-vector is a flea and reservoir hosts are rodents |
|
|
Term
|
Definition
-caused by Y. pestisoccurring in wild animals
-vector is a flea and reservoir hosts are rodents
-humans become infected by visiting prairie dog towns |
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Term
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Definition
-spread by contact with ticks that have previously fed on infected rabbits (called rabbit fever)
-pathogen is bacterium Francisella tularensis
-highly debilitating affecting liver
and spleen if
-typical pathology is throat infection,
vomiting, diarrhea, fever, and
pneumonia symptoms |
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Term
| Natural conditions for fisheries diseases |
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Definition
- animals in fresh & salt water harbor disease
- parasites harbored by aquatic animals lost to vast expanse of water
- light infections do little harm to aquatic hosts
- under crowded conditions or inadequate water; fish may become heavily diseased & die |
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Term
| Man & disease in aquatic environments |
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Definition
- fisherman who find diseased animals discard them
- majority of diseases cannot harm humans if animal cooked thoroughly
- most parasites of aquatic animals will not live in man |
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Term
| disease & commercial fisheries |
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Definition
- commercial fisheries suffer great losses ea. yr b/c of disease
- Minnesota ciscos (fish) infected w/ tapeworm cysts
- no known control for most diseases in marine environments (it's a big ocean out there!), but some control in small bodies of water |
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Term
| Viruses/Bacteria in Fisheries |
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Definition
1. Baculovirus penaei
2. Vibrio parahaemolyticus (AKA vibrio) |
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Term
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Definition
- infects digestive gland of shrimp
- large, refractile polyhedral-shaped inclusion body seen w/ microscope
- not fatal, but overcrowding makes it spread
- pink, brown, & white shrimp affected |
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Term
| Vibrio parahaemolyticus (AKA vibrio) |
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Definition
- bacteria occurs in crabs, thru other Vibrio spp. infect other fisheries
- produces large jelly-like blood clots & nodules in gills
- can kill crab
- zoonosis: infected crabs cause food poisoning/intestinal upset
- minimal heating eliminates threat |
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Term
| Fungi diseases in Fisheries |
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Definition
1. Black gill disease
2. Foot disease |
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Term
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Definition
a. fungus that infects shrimps
b. evidenced by dark pigment in gills |
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Term
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Definition
a. fungus that infects oysters (Crassostreasp.)
b. causes small rough greenish spots inside the shell
under the attachment of the adductor muscle
c. in severe cases, part of the muscle separates
from the shell and a horny elastic cyst forms
d. the valves cannot close properly, and oyster is
more susceptible to predation |
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Term
| Flagellates in Fisheries (Amyloodinium ocellatum) |
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Definition
a. dinoflagellate that infects marine fish
b. causes serious problems for captive fish (hatcheries) due to rapid multiplication
c. typically attach to the gills and high numbers can be fatal
d. other dinoflagellate spp are known to infect gills of freshwater fish |
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Term
| Sporozoans of Fisheries (Eimeria spp) |
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Definition
a. coccidians of many types cause serious economic losses to untreated, infected fish
b. form resistant spores, hence their taxonomic name
c. different coccidians infect different tissues (e.g., testes of menhaden; swim bladder of cod).
d. coccidians are well known as they are the malaria-causing organisms, and can also cause severe economic losses in poultry and livestock |
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Term
| Ciliates of Fisheries (Ichthyophthirius multifilis) |
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Definition
Common name: Ich
a. fish can be seriously infected with this ciliate
b. appears as little white spots moving slowly over the fish
c. they feed on tissues just under the outer layer of the skin eventually causing irritation and infection
d. most managers treat the short-lived free-swarming stage, but feeding stages (trophonts) typically remain and can prolong infectione. ich is the largest protozoan found on fish |
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Term
| Microsporidians in Fisheries (Ameson michaelis) |
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Definition
a. causes severe damage specifically to blue crabs
b. internal infection, so it is not lost during molting and affects the crab’s behavior
c. heavy infections easily recognized because muscle tissue acquires a chalky appearance in joints of appendages and abdomen turns grayish
d. muscle tissue surrounding the masses of spores breaks down, and crab becomes weakened and vulnerable to stress (which increases fatalities) |
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Term
| Myxosporidians in Fisheries (Myxobolus lintoni/cerebralis) |
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Definition
Common Name: whirling disease
a. M. lintonicauses tumorous growths on fish (e.g., sheepshead minnow)
b. might be evidence for a connection between this parasite and pollution/stress
c. M. cerebralisinvades and erodes cartilage supporting the central nervous system of salmonids
d. this parasite causes erratic circular swimming and blackened tails in heavy infections |
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Term
| Cestodes in Fisheries (Diphyllobothrium latem) |
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Definition
Fish Tapeworm
a. ZOONOSIS–tapeworms are considered important in fisheries if they can infect man
b. adults are in the intestine of bears, dogs, and other animals and usually can cause some harm if in great abundance
c. the larval forms are found in fish and copepods; the larvae in fish are infective to man if not properly cooked
d. this species is found in freshwater pike, trout, orperch; other species infect marine fish and invertebrates as well.
e. tapeworms infect many invertebrates and adults are found in all groups of vertebrates |
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Term
| Monogeneans in Fisheries (Discocotyle salmonis) |
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Definition
Gill worm
a. occurs on the gills of trout and salmon
b. many monogenean spp are mucus, epithelial or
blood feeders and sometimes are so numerous that fish
is seriously affected
c. they utilize a direct life cycle
d. monogeneans are very active, easily observed,
and make great biological tags
e. parasitize lower vertebrates |
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Term
| Digeneans in Fisheries (Clinostomum marginatum) |
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Definition
Flukes
a. trematode larvae and adults are found in all vertebrate groups and inverts; larval form of this species causes “yellow grub” in freshwater fish
b. digeneans infect variety of sites in hosts: internal organs, tissues, eyes, etc. High intensities can debilitate or kill host (e.g. Bolbophorus)
c. they utilize an indirect life cycle (more players in the game)
d. also make great biological tags and indicators of host environment
e. ZOONOSIS; some species are infective to man (e.g., Paragonimus westermaniin the lungs of man obtained from infected crayfish) |
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Term
| Nematodes in Fisheries (Anisakis) |
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Definition
Roundworms
a. ZOONOSIS; larval nematodes of this genus are in the tissues of fish & typically utilize marine mammals as final hosts but can be infective to man -anisakiasis(e.g., eating raw, undercooked fish/sushi)
b. nematode larvae and adults are found in all vertebrates groups and inverts. Larval Contracaecumspp are found in many important commercial/recreational fishes and utilize birds as final hosts
c. inhabit a wide variety of sites within hosts
d. they utilize both direct and indirect life cycles and paratenic hosts.
e. Some can be quite large, but can be killed by heat or freezing |
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Term
| Acanthocephalans in Fisheries (Serrasentis sagittifer) |
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Definition
Spiny-headed worms:
a. this conspicuous acanthocephalan is found in the gut of a very popular commercial and recreational fish along the Gulf coast -cobia (i.e., lemonfish). Another species, Dollfusentis chandleriis found in croaker.
b. some species cause substantial pathology to their hosts since their spiny heads perforate the intestinal wall.
c. intensities can be quite high for this parasite (e.g., 450+ were found in a single croaker)
d. ZOONOSIS; adults utilize all vertebrates, and larvae are found in terrestrial, freshwater and marine invertebrates; many spp use paratenic hosts. |
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Term
| Crustaceans in Fisheries (Pennelidae, cymnothoid isopod, fish lice) |
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Definition
a. many types of crustacean parasites
(e.g., copepods, isopods, barnacles etc.)
b. they are one of the most easily seen parasites,
so they are familiar to many fishermen. Sea lice appear
as tiny brownish specks moving about on the sides of fish.
c. they infect fish and invertebrates
d. can cause considerable damage to and debilitate
their hosts attaching to scales, fins, gills, mouth and
through tissues. They can also lead to secondary infection.
e. aquatic crustaceans are not infective to man,
but some can cut, slice, or clamp you if you handle them. |
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Term
| Leeches in Fisheries (Myzobdella lugubris) |
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Definition
Crab leech
a. leeches can parasitize fish and invertebrates and are the largest external parasites found on fish
b. many spp are blood suckers, but several are not
c. usually attach to the gills, opercles, nostrils, fins, and body surfaced. they can also serve as vectors for blood parasites (e.g., sporozoans) |
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Term
| Reasons conservationists are ill-equipped to manage disease: |
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Definition
1.It is difficult to identify or to predict the circumstances under which disease might pose a risk.
2. Mgmt strategies to deal with these risks are not well established
3. Techniques and tools for preventing or responding to disease threats are not well developed
4. Because disease is often overlooked as a conservation
problem until a major problem occurs, there is little
funding or political will for putting ideas into practice |
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Term
| Increasing importance of disease in wildlife conservation: |
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Definition
- rapid pop growth & increased moblilization threatens habitats & favors spread/persistence of disease
- general deterioration in infrastructure for domestic animal disease control in developing countries
- human activity & environmental degradation -> alters dynamics of disease in natural pops
- appearance of new pathogens w/ increased virulence |
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Term
| One of the big avenues for reducing disease in endangered and threatened animals is reducing their contact with _____________ ___________. |
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Definition
reservoir hosts
EXAMPLE: Parc National des Volcans in Rwanda does not permit sick park rangers, guides, or tourists to visit habituated groups of mountain gorillas
EXAMPLE: Management plans for bighorn sheep in California recommend a 15-km buffer zone to separate bighorn populations from domestic sheep carrying potentially threatening infections. |
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Term
| What we need to know now to help fight wildlife/fisheries diseases in the future |
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Definition
1. Wildlife managers/biologists need technical information
2. There is a need for epidemiological studies of animal disease.
3. We need better risk assessment informationfor endangered/threatened spp
4. Wildlife managers/biologists need a better understanding of pathogens in multi-host systems, which is critical for determining the management strategies that will be most appropriate for field use. |
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