Internal Parasites of Internal Parasites of LivestockLivestockInternal Parasites of Internal Parasites of LivestockLivestock

Internal Parasites of Internal Parasites of LivestockLivestockInternal Parasites of Internal Parasites of LivestockLivestockInternal Parasites: live within the

internal organs of livestock◦They are not visible◦Effects on the host may be visible

Divided into three groups◦Roundworms◦Tapeworms◦Flukes

RoundwormsRoundwormsRoundwormsRoundwormsMost important from economic

standpointMany different typesAffect almost every type of

livestock

Stomach WormsStomach Worms(Roundworm)(Roundworm)Stomach WormsStomach Worms(Roundworm)(Roundworm)

Host: Every species of livestock

Life Cycle: ◦ Adults live in stomach wall.◦ Eggs pass from host and hatch into

larvae◦ Larvae are eaten by animal and travel

to stomach where they mature.

Stomach WormsStomach Worms(Roundworm)(Roundworm)Stomach WormsStomach Worms(Roundworm)(Roundworm)

Damage:◦ Penetrate

stomach lining◦ Reduce digestion

of nutrients◦ Young

undernourished animals are hit the hardest

Symptoms◦ Anemia- paleness

of gums and white of eyes

◦ Dull hair coat◦ Scours◦ Severe infestation

can cause weight loss and death

StrongylesStrongyles(Roundworm)(Roundworm)StrongylesStrongyles(Roundworm)(Roundworm)

Host: All species of livestock◦ Cattle & horse

can build up immunity by ages 4 or 5

Life Cycle:◦ Adult is attached to

lining of intestines◦ Eggs pass from

host◦ Larvae attach to

grass and are eaten by animal

◦ Pass through stomach and attach to intestinal wall

StrongylesStrongyles(Roundworm)(Roundworm)StrongylesStrongyles(Roundworm)(Roundworm)

Damage:◦ Most detrimental◦ Anemia◦ Scar tissue

reduces digestion of nutrients

◦ Major cause of Colic in horses

◦ Poor feed conversion

Symptoms◦ Anemia◦ Weight Loss◦ Scouring◦ Loss of appetite◦ Prostration◦ Rough hair coat

AscaridsAscarids(Roundworm)(Roundworm)AscaridsAscarids(Roundworm)(Roundworm)

Largest of round worms◦Can reach 8 to 15 inches in length

Mainly affects younger animalsHost: primarily cattle, sheep,

hogs, and horses

AscaridsAscarids(Roundworm)(Roundworm)AscaridsAscarids(Roundworm)(Roundworm)

Life Cycle:◦Eggs passed in feces contaminate

pastures◦Animals ingest ◦Larvae burrow into wall of intestine ◦Migrate to liver, heart, and lungs◦Animal coughs up eggs and are

swallowed◦Reach intestines a 2nd time and

develop into adult stage

AscaridsAscarids(Roundworms)(Roundworms)AscaridsAscarids(Roundworms)(Roundworms)

Damage:◦ Develop

pneumonia◦ Weight loss◦ Lung damage◦ Colic in horses

Symptoms◦ Weight loss◦ Dull hair coat◦ Colic

PinwormsPinworms(Roundworms)(Roundworms)PinwormsPinworms(Roundworms)(Roundworms)

Small and found in colon or rectum of horses

Host: mainly horses, but can be found in other livestock species.

PinwormsPinworms(Roundworms)(Roundworms)PinwormsPinworms(Roundworms)(Roundworms)

Life cycle: ◦Adult females lay eggs around the

anus of horse◦Eggs drop off and contaminate

pastures, stables, watering and feeding area

◦Eggs are ingested by animal◦Pass to colon and rectum and

mature

PinwormsPinworms(Roundworms)(Roundworms)PinwormsPinworms(Roundworms)(Roundworms)

Damage:◦ Minor damage is

caused◦ Cause irritation

around the tail

Symptoms:◦ Tail rubbing◦ White scales

deposits are visible around anus

HabronemaHabronema(Roundworm)(Roundworm)HabronemaHabronema(Roundworm)(Roundworm)

Affects host in two stagesHost: Horse is major host

◦House fly is intermediate host

HabronemaHabronema(Roundworm)(Roundworm)HabronemaHabronema(Roundworm)(Roundworm)

Life Cycle:◦Adult stage is found in stomach ◦Larvae is passed which is ingested

by house fly◦House fly deposits eggs on lips of

horse◦Horse swallows eggs and they

mature in horses stomach

HabronemaHabronema(Roundworm)(Roundworm)HabronemaHabronema(Roundworm)(Roundworm)

Damage:◦ Summer sores

can form if larvae are deposited in open wounds

◦ Disfigure horses◦ Hard to heal

Symptoms:◦ Presence of

summer sores◦ Excessive tearing

and running of eyes

◦ Open sores

LungwormsLungworms(Roundworms)(Roundworms)LungwormsLungworms(Roundworms)(Roundworms)

Affect circulatory system & lungsHost: All species of livestock

LungwormsLungworms(Roundworms)(Roundworms)LungwormsLungworms(Roundworms)(Roundworms)

Life Cycle:◦ Eggs laid in lungs of animals◦ Coughed up & swallowed◦ Eggs hatch in stomach and larvae are

passed◦ Develop in moist earth or water◦ Ingested by animal◦ Burrow into lymph nodes and are carried to

lungs where they mature

LungwormsLungworms(Roundworms)(Roundworms)LungwormsLungworms(Roundworms)(Roundworms)

Damage:◦ Mechanical

blockage of lungs◦ Collapse of

infected area◦ Blockage of

windpipe and bronchea

Symptoms:◦ Coughing◦ Fast or forceful

breathing◦ Fever◦ Animal reluctant

to move◦ Goes off of feed

and water

TapewormsTapewormsTapewormsTapewormsLess important than roundworms

3 species of tapeworms◦Broad tapeworm◦Beef tapeworm◦Pork tapeworm

Broad TapewormBroad TapewormBroad TapewormBroad TapewormHost: All classes

of livestock and also in man

Reach up to 10 feet in length

Life Cycle:◦ Adult lives in

small intestine◦ Segments

containing eggs break off and pass out of animal

◦ Eggs are eaten by oribated mite

◦ Mites are eaten by host and eggs hatch in small intestine

Broad TapewormBroad TapewormBroad TapewormBroad TapewormDamage:

◦ No physical damage

◦ Tapeworm is in competition with animal for food.

Symptoms◦ Weight loss◦ Diarrhea◦ emaciation

Both are similar and almost identical

Host: ◦Beef tapeworm- cattle and man◦Pork tapeworm- swine and man◦Man is necessary intermediate host

Reach 5 feet in length

Beef and Pork TapewormBeef and Pork TapewormBeef and Pork TapewormBeef and Pork TapewormLife Cycle:

◦ Adult lives only in man◦ Eggs contaminate the feed of animal

through human contact◦ Animal ingests feed and eggs pass to

intestinal wall◦ Larvae lodge in some muscle causing a

cyst◦ Passed back to man when infected meat is

eaten

Beef and Pork TapewormBeef and Pork TapewormBeef and Pork TapewormBeef and Pork TapewormDamage:

◦ Little economic damage to cattle

◦ Causes mealy beef

Symptoms:◦ No visible

symptoms except when animal is slaughtered

FlukesFlukesFlukesFlukesSeveral speciesLiver Fluke is the most important

Liver FlukeLiver FlukeLiver FlukeLiver FlukeHost:

◦Parasite of cattle, sheep, goats, and man

◦Damaging to young animals

Liver FlukeLiver FlukeLiver FlukeLiver FlukeLife Cycle:

◦ Adult lives in bile ducts◦ Eggs passed into intestines and passed

out◦ Eggs must be in water to hatch◦ Larvae hatch and seek a snail◦ Larvae develops on snail and then attaches

to a plant◦ Animals ingest infected plant◦ Flukes pass to intestines and burrow

through abdominal cavity to the lungs.

Liver FlukesLiver FlukesLiver FlukesLiver FlukesDamage:

◦ Irritation and thickening of bile duct

◦ Fibrosis of the liver

Symptoms:◦ Anemia◦ Weight loss◦ Death if not

treated.

TomorrowTomorrowTomorrowTomorrowWe will go over control methods

of internal parasites.