Pig Parasites

Question 1

Which parasites of pigs are pasture transmitted?

Answer 1

Hyostrongylus rubidus, Oesophagostomum spp., Metastrongylus spp.

Question 2

Which parasites are transmitted in indoor pigs?

Answer 2

Ascaris suum, Trichuris suis, Sarcoptes scabiei var. suis,

Question 3

Which parasites are eradicated in commercial swine in Canada?

Answer 3

Trichinella

Question 4

Which parasites are not in pigs in Canada?

Answer 4

Taenia solium

Question 5

What are the pig parasites?

Answer 5

Question 6

Life cycle of Hyostrongylus rubidus?

Answer 6

typical life cycle of trichostrongyles

Question 7

Pathogenesis of Hyostrongylus rubidus?

Answer 7

• rarely causes clinical problems
  but possibly:
• ulceration, stomach perforation
• hemorrhage, anemia (blood feeder)
• decreased milk yield & fertility

Question 8

Life cycle of Ascaris suum?

Answer 8

• adults in SI (extremely fecund females)
• eggs pass in feces
• larval development occurs entirely w/in egg, temp dependent development
• extremely hardy eggs (7-10 yrs in shaded, damp conditions)
• PPP: 6-8 wks
• no transplacental or transmammary infection

Question 9

What is the pathogenesis of Ascaris suum?

Answer 9

• often asymptomatic
  MIGRATING LARVAE can cause:
• physical damage to liver (1st infection)
• hypersensitivity, allergic inflammation (esosinophilic), “milk spots” in liver (following infections)
• emphysema, “HEAVES” or “THUMPS”, & secondary bacterial/viral infections in lungs
  ADULT WORMS can cause:
• subclinical effects, performance problems, rarely: obstruction, perforation of the gut wall, occlude bile duct

Question 10

Life cycle of Trichinella

Answer 10

direct life cycle
- adult nematodes in small intestine of host
- L1 in muscles of SAME HOST
- foodborne transmission only (no fecal or environmental stage)

Question 11

Clinical signs of Trichinella in people?

Answer 11

• often subclinical
• adults in small intestine: D+
• larvae in muscles: myalgia, fever, periorbital oedema, myocarditis (potentially fatal)

Question 12

What is the life cycle of Strongyloides ransomi (S. suis now)?

Answer 12

• adult females in SMALL INTESTINE
• homogonic & heterogonic lifecycles
• percutaneous & oral transmission of L3
• prenatal & TRANSMAMMARY pathogen of nursing piglets (2 wk old)

Question 13

Pathogenesis of Strongyloides ransomi (S. suis now) in nursing piglets?

Answer 13

catarrhal enteritis, dysentery, anemia (75% mortality)

Question 14

What is the life cycle of Oesophagostomum spp.?

Answer 14

• typical trichostrongyle life cycle
• L4 encyst in nodules in LARGE INTESTINE

Question 15

Subclinical and clinical effects of Oesophagostomum spp.?

Answer 15

• Piglets: D+. weight loss, anorexia
• finishing pigs: reduced weight gain
• sows: reduced litter sizes & milk production

Question 16

What is the life cycles of Trichuris suis?

Answer 16

• L1 develops inside egg, infective
• simple mucosal migration

Question 17

What is the pathogenesis of Trichuris suis?

Answer 17

• often asymptomatic
• anorexia, poor weight gain, large bowel D+ (mucous +/- blood), hypoalbuminemia/anemia

Question 18

What is the life cycle of Metastrongylus spp.?

Answer 18

• indirect life cycle w/ earthworm IH
• pig passes larvated eggs in feces
• earthworm eats eggs
• translation L1-L3
• pig eats L3 in earthworm

Question 19

what is the symptoms of Metastrongylus spp. in pigs?

Answer 19

verminous bronchopneumonia in young outdoor pigs (like husk in cattle)

Question 20

What is the life cycle of Taenia solium?

Answer 20

predator-prey indirect life cycle
- human DH, swine IH (people can also serve as IH)
- eggs are immediately infective & resistant

Question 21

What conditions do Taenia solium cause?

Answer 21

neurocysticercosis & epilepsy

Question 22

Symptoms of Sarcoptes scabiei var suis?

Answer 22

thick scabs & crusts, highly pruritic, major production losses

Question 23

Symptoms of Haematopinus suis?

Answer 23

itchy bites can lead to self excoriation & weight loss

Question 24

Symptoms of Cystoisospora suis?

Answer 24

yellow-gray, pasty D+ (often no blood), loss of condition, dehydration, high morbidity, low mortality

Question 25

Life cycle of Toxoplasmosis in pigs?

Answer 25

- pigs are a common IH for Toxoplasma gondii - most often acquired horizontally - consume sporulated oocysts in feed or water contaminated w/ cat feces - consume tissue cysts in undercooked meat or rodents - pigs are a common source of human infection

Question 26

Life cycle of Balantidium coli in pigs?

Answer 26

- large intestinal ciliated protozoan - trophozoites in gut - cysts in feces

Question 27

symptoms of Balantidium coli in pigs?

Answer 27

- generally harmless in pigs, incidental finding on histopathology - rarely causes ulcers, D+

Question 28

symptoms of Balantidium coli in people?

Answer 28

- can cause D+, nausea, vomiting, & anorexia

Question 29

Which genera produce trichostrongyle type eggs in pigs?

Answer 29

Hyostrongylus rubidus, Oesophagostomum spp.

Question 30

Which genus of helminths are displaying AHR?

Answer 30

- Oesophagostomum spp. resistant to bezimidazoles

Question 31

Which ectoparasites are important in pigs?

Answer 31

Sarcoptes scabiei var suis, Haematopinus suis (sucking louse), Erystalis tenex (hover fly)

Question 32

What are the different types of coccidiosis in pigs?

Answer 32

1. Eimeria spp. - harmless, generally in adult pigs 2. Cystoisospora suis - pathogenic in piglets < 2 wk old (yellow-gray pasty D+ (often no blood), loss of condition, dehydration, high morbidity, low mortality)

Question 33

Which pig parasites are zoonotic?

Answer 33

- Ascaris suum (to other animals) - Trichinella (eating undercooked meat, CFIA) - Trichuris suis (but natural transmission is rare & doesnt usually fully develop in people) - Taenia solium (CFIA) - Sarcoptes scabiei var suis (transient infection) - Toxoplasmosis (pigs are common source of infection for humans) - Balantidium coli

Question 34

Regulatory control of Trichinella?

Answer 34

- CFIA maintains Canada's disease-free status (surveillance, regulation, & testing) - prohibits feeding of meat products to pigs - tests all horses slaughtered in CFIA regulated abattoirs for export certification - REPORTABLE ANIMAL DISEASE