unit 11 nervous system diseases

7/28/2019 Unit 11 Nervous System Diseases

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Unit 11: Nervous

System Diseases


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Unit 11: Nervous System

Diseases Tetanus

Acute, highly infectious

Contagious?Affects

Humans

Horses

Sheep Swine

cattle


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Diseases Infectious organisms gain entrance to the

body through traumatized tissue

Deep wounds that seal quickly are often mostproblematic

Docking, castration, shearing cuts, dehorning,etc.

Cause Bacterial infection


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Diseases Clinical Signs

Localized infection (doesnt go systemic)

Gives off a very powerful toxin (100x morepowerful than some poisons)

Passes along the nerves to the spinal cord

A few days to several weeks after initialinfection

Stiffness moderate to pronounced

lock-jaw

Ears, tail, eyes retracted


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Diseases Rapid symptom development often = death

Recovery usually >50%

Prevention Thorough cleansing of wounds

Antiseptic procedures Docking, castrating, surgeries, etc.

Immunity can be raised w/ a toxiod orantitoxin Toxoid

Injection of neutralized tetanus toxin tostimulate the bodys immune response


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DiseasesAntitoxin

Concentrated serum w/ tetanus toxinantibodies taken from another animal

administered as an injection Some vaccines also available

Treatment

Larges doses of tetanus antitoxin, sedatives,

and care Reopen site of infection, clean, drain

Antibiotic therapy


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Diseases Pseudorabies

Acute viral infection of pigs & cattle,

sometimes sheep Non-contagious in cattle, highly

contagious in swine

Spread by bites from infected hogs

Cause Herpes virus

Swine are long-term carriers


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Diseases Disease waits for stress periods to show itself

State blood testing is required for swinetransport

Can travel between herds ~2 mi

Clinical Signs Cattle will have usually been associated w/

swine at some juncture

Intense itching at the site of infection Newborn pigs can go from normal to coma in

6-24 hrs.


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Diseases Older swine

Show some CNS symtpoms

Incoordination, paralysis, muscle spasms, etc.

Mild fever, depression, finicky appetite

Abortions in pregnant sows, dead or mummifiedpigs if they dont abort

Infected breeding females often hard to settle

PreventionVaccinaton

No Treatment available


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Diseases Equine Encephalomyelitis

Infectious disease spread by insects

Characterized by nervous disorders andhigh mortality

Usually individual cases, unless conditions

become favorable for high populations ofmosquitoes


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Diseases Cause

Viral

3 types Western, Eastern, Venezuelan

Western & Venezuelan most common in our area

Birds help develop the disease

Clinical SignsAffects CNS

Nervousness, depression, impaired vision,etc.


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Diseases Lay on side and gallop

Mild cases often recover, acute cases oftendie

50% mortality for Western

90-100% for Venezuelan

Prevention

Vaccination Mosquito control methods

Discourage bird roosting around the barn


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Diseases Treatment

Not very effective because of the rapid natureof the disease

Mostly supportive therapy

Scrapie Common in sheep and goats

Contagious Transmissable agent can withstand boiling &

exposure to chemical agents


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Diseases Can occur more frequently in certain

breeds or families Question of heritability

Some Suffolk breeders DNA test

Clinical Signs 18-24 mo incubation period

Progressive wt loss, hind end weakness First signs:

Nervousness, restlessness, excitability, itching,patches of wool rubbed off


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Diseases No loss of appetite, normal temp

Prevention

No vaccine Quarantine and slaughter for control

No treatment


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Diseases BSE

Slow degenerative disease of the CNS

Unknown cause

Infects brain and spinal tissue

Related to an infectious human disease

Not transmitted in milk Can be passed in meat?


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Diseases No know treatment, or control

Prevention

Testing Quarantine

unit 11 nervous system diseases

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