1. Internal Parasites of Livestock

2. Internal Parasites of Livestock
Internal 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

3. Roundworms Most important from economic standpoint
Many different types
Affect almost every type of livestock

4. Stomach Worms (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.

5. Stomach Worms (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

6. Strongyles (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

7. Strongyles (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

8. Ascarids (Roundworm) Largest of round worms
Can reach 8 to 15 inches in length
Mainly affects younger animals
Host: primarily cattle, sheep, hogs, and horses

9. Ascarids (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

10. Ascarids (Roundworms)
Damage:
Develop pneumonia
Weight loss
Lung damage
Colic in horses
Symptoms
Weight loss
Dull hair coat
Colic

11. Pinworms (Roundworms)
Small and found in colon or rectum of horses
Host: mainly horses, but can be found in other livestock species.

12. Pinworms (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

13. Pinworms (Roundworms)
Damage:
Minor damage is caused
Cause irritation around the tail
Symptoms:
Tail rubbing
White scales deposits are visible around anus

14. Habronema (Roundworm)
Affects host in two stages
Host: Horse is major host
House fly is intermediate host

15. Habronema (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

16. Habronema (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

17. Lungworms (Roundworms)
Affect circulatory system & lungs
Host: All species of livestock

18. Lungworms (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

19. Lungworms (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

20. Tapeworms Less important than roundworms 3 species of tapeworms
Broad tapeworm
Beef tapeworm
Pork tapeworm

21. Broad Tapeworm Host: 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

22. Broad Tapeworm Damage: Symptoms No physical damage
Tapeworm is in competition with animal for food.
Symptoms
Weight loss
Diarrhea
emaciation

23. Beef and Pork Tapeworm 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

24. Beef and Pork Tapeworm Life 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

25. Beef and Pork Tapeworm Damage: Symptoms:
Little economic damage to cattle
Causes mealy beef
Symptoms:
No visible symptoms except when animal is slaughtered

26. Flukes
Several species
Liver Fluke is the most important

27. Liver Fluke Host: Parasite of cattle, sheep, goats, and man
Damaging to young animals

28. Liver Fluke Life 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.

29. Liver Flukes Damage: Symptoms: Irritation and thickening of bile duct
Fibrosis of the liver
Symptoms:
Anemia
Weight loss
Death if not treated.

30. Tomorrow
We will go over control methods of internal parasites.