Nematodes of Swine

Question 1

Hyostrongylus rubidus (common name)

Answer 1

red stomach worm

Question 2

Hyostrongylus rubidus (pathology)

Answer 2

adults suck blood; larvae in gastric glands may form nodules

Heavy infection: anemia, weakness, rapid loss of condition

Question 3

Ascaris suum (importance)

Answer 3

decreased feed efficiency, diarrhea, weight loss, occ. intestinal obstruction/rupture
Liver migration leaves white scars called “milk spots” – liver condemned at slaughter
Verminous pneumonia

Question 4

Ascaris suum (route of infection)

Answer 4

L2 egg infective – hepatotracheal migration

Question 5

Strongyloides ransomi (common name)

Answer 5

threadworm of pig

Question 6

Trichinella spiralis (life cycle)

Answer 6

female in small intestine  large #s active larvae  blood vessels (several weeks in circ.)  encyst in muscle tissue (viable for years)  tissue eaten by another host (rat, man, pig)  (pigs IH or FH)  larvae freed from cysts  mature in intestine  copulate  produce larvae for about 2 weeks

Question 7

Trichinella spiralis (significance)

Answer 7

In pigs, not very pathogenic
Carcasses may be condemned – take random biopsies from jaw muscle and diaphragm

In humans, may cause severe and even fatal infections
Intestinal adults – nausea, vomiting, diarrhea
Larvae – muscle stiffness, pain – death may occur by paralysis of respiratory muscles

Question 8

Trichinella spiralis (control)

Answer 8

Cook garbage fed to swine
Control rat infestation of pig farms
To prevent human infection, thorough cooking (to 160º F) or freezing of pork, game animals

Question 9

Oesophagostomum sp

Answer 9

same as in ruminants

Question 10

Trichuris Suis

Answer 10

Same as in other species

Question 11

Metastrongylus sp (common name)

Answer 11

lungoworm of pig

Question 12

Metastrongylus sp (site)

Answer 12

bronchi, bronchioles

Question 13

Metastrongylus sp (IH)

Answer 13

earthworms