Transcript Unit 16: Parasitology

Unit 16: Parasitology
Unit 16: Parasitology
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Lost production due to parasites = $10-$12
billion/yr in U.S.
Most economic losses in young animals
Complete eradication impossible, must
control effectively
Two types:
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Ectoparasites
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Live on exterior of body
Endoparasites
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live on interior of body
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Damage from parasites
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Ectoparasites
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Damaging & irritating the skin
Creating excitement, restlessness, nervousness
Transmitting infectious organisms
Sucking blood
Endoparasites
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Absorbing feed intended for the host
Sucking blood & lymph from host
Cause internal bleeding
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Parasites can mass migrate to major organs
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Obstructing bile ducts, intestines, circulatory system
Provide entry for infectious organisms
Liver, lungs, abdominal, chest, blood vessels
Symptoms
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Poor appetite, dehydration, unthriftyness, diarrhea, wt
loss, rough hair coat, slow gains, emaciation, weakness
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Diagnosis of Parasitism
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Check fecal samples for parasite eggs
Fecal examination
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Smear fecal sample on a slide
Check w/ microscope
Can lead to false sense of parasite load
Flotation method
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Float parasite eggs to top of fecal sample using solution
“catch” parasite eggs on a slide
Examine w/ microscope
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Most accurate method of diagnosis
Life cycles
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Parasite limited to outside of animal
Ectoparasites that penetrate into the body
causing tissue damage
Endoparasites – eggs ingested into stomach,
hatch & mature, adults remain in stomach entire
life, eggs passed out in feces
Require assistance from intermediate host to
complete life cycle - tapeworms
Unit 16: Parasitology
Ingested into host, migrate from digestive tract to
another part of host – ascaris worms, lungworms
Require assistance from intermediate host, also
migrate to other body parts to complete life cycle
– liver flukes, lungworms
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Control measures
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Proper nutrition
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Maintain high nutritional status
Keep pasture high quality
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Prevent overstocking
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Increased stocking rates also increases parasite load
Overstocking results in overgrazing
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Pasture rotation
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As grass is grazed closer to the ground, parasite risk
increases
Most problematic during warm, wet conditions
Keeps from overgrazing one single pasture
Prevent mixed grazing
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Don’t graze older and younger animals on same
pasture, if possible
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Sanitation
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Keep lot, pasture dry
Maintain good drainage
Clean feed bunks
Controlling Parasites
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Endoparasites
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Tapeworms, roundworms, flukes, flatworms
Factors to consider before treatment
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Pregnancy status
Other illness & medications
Method of drug administration
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Rotate dewormers, keep on a schedule
Keep in mind the life cycles
Ectoparasites
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Flies, lice, ticks, mites
Cause: irritation, decreased production, tissue damage,
etc.
Consider control measures carefully
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Keep operation sanitary first
Be careful of drug reactions & residues
Be cautious of handling risks