Swine Parasites

Question 1

What parasite of swine causes respiratory signs known as “Thumps”?

Is the life cycle indirect or direct?

Describe the life cycle

PPP?

What life stages will cause appearance of “milk spots”

Answer 1

Ascaris suum

direct

Tracheal migration! (ingesttion of infective larvated eggs –> eggs hatch in SI and larvae penetrate intestinal walls to get into venous circulation –> L2 enter liver molt to L3 and migrate –> carried by venous circulation to lungs and molt to L4 –> L4 coughed up and swallowed?? and end up in SI –> L4 molt to adults in SI

7-9 weeks

L2 in liver (24 hrs of infection) and L3 in lungs (4-7 days of infection)

Question 2

What feed additive can be used in swine to kill Ascaris suum?

What life stages is it effective for?

Withdrawal time?

Is A. suum zoonotic?

Answer 2

Pyrantel tartrate

adults, L2, L3

24 hrs

Yes

Question 3

What parasite of swine belongs to the Rhabitoidea superfamily and only has parasitic females

Answer 3

Strongyloides ransomi

Question 4

How do pigs get infected with S. ransomi?

Where do adults reside?

What is unique about its life cycle?

Answer 4

Ingestion of L3, percutaneous penetration, transmammary

Small Intestine

Adults can be free living

Question 5

What drugs are efficacious for S. ransomi in pigs?

Answer 5

Ivermectin and doramectin

Question 6

What parasite is responsible for baby pig coccidiosis?

How old are the pigs that get coccidiosis?

PPP?

Pathology caused by coccidia?

Answer 6

Isospora suis

5-10 days old

6-8 days

Yellowish/gray , pasty to liquid, rancid smelling diarrhea, dehydration

Question 7

How can you diagnose cystoisospora suis?

Answer 7

oocysts in feces

necropsy: impression smear mid jejunum and ileum

Question 8

What treatments are available?

Answer 8

NO FDA APPROVED Tx

Ponazuril (not approved)

Question 9

What parasite of swine is known as the swine nodular worm?

Describe the life cycle of this parasite

PPP?

Answer 9

Oesophagostomum spp.

Strongyle type eggs shed in feces –> L1 to L3 on grass –> L3 ingested and form nodules in SI –> L3 molt and L4 exit nodules and migrate to colon –> L4 may either undergo a final molt to adult or or form another nodule to overwinter and then molt to adult

7 weeks

Question 10

Efficacious drugs for Oesophagostomum spp.?

Answer 10

Avermectins: Ivermectin, doramectin,

Pyrantel tyrtrate

Question 11

What parasite is known as the whipworm in swine?

Where does it reside as an adult?

If a pig is exposed to infective stages for whips and ascarids at the same time, which parastie’s eggs will we see first in the feces?

PPP of whips?

Treatment options?

Answer 11

Trichuris suis

cecum & colon

Whips

6-7 weeks

Fenbendazole, doramectin

Question 12

What parasite is the lungworm of swine?

How do we prevent infection?

How can we identify adults of this parasite?

Answer 12

Metastrongylus apri

Prevention: do not raise pigs on dirt or pasture (do not let pigs ingest the I.H., earthworms)

Location in which they are found: bronchioles, bronchi

Question 13

What do you need to keep on our rule out list when presented with pigs raised on dirt with respiratory signs (“thumps”)

Answer 13

Metastrongylus apri and larval migration (L3) of Ascaris suum

Question 14

What drugs can we use for Metastrongylus apri

Answer 14

Doramectin, ivermectin, fenbendazole

Question 15

What parasite historically associated with swine has been said to parasitize more animals than any other worm?

Which genotype (species) is the most common?

What is the I.H. for this parasite? D.H.?

Answer 15

Trichinella sp.

Genotype T1 (T. spiralis)

I.H. = Any animal, D.H. = any animal

Question 16

Regarding its life cycle, what is unique about it (clue: true predator/prey relationship)

Life cycle of Trichinella spiralis?

Answer 16

No life stages occur outside the host

Adults in small intestine mucosa –> deposit larvae in mucosa or lymphatics –> larvae enter lymphatics to get to venous system –> heart –> lungs –> systemic circulation & striated muscle and encyst –> encysted larvae ingested by another host –> larvae excyst in intestines of new host –> enter mucosa of intestines and molt to adults

Question 17

What is the name of the structure that Trichinella spiralis larvae form when they encyst in muscle tissue?

Zoonotic?

Answer 17

Nurse cell (larvae-muscle cell complex)

about 70 um coiled up

YASSSS

Question 18

For prevention of Trichinella zoonosis, what cooking temperatures are recommended?

Answer 18

145F for whole cuts of meat, 160 for ground meat

160 for wild game, 165 for poultry

Question 19

What parasite is responsible for causing “Measly Pork”? What is another name for this disease?

D.H.?

I.H.?

Answer 19

Taenia solis, cysticercosis

Human

Swine or Human

Question 20

For Taenia solis, what is the location life stage found in humans and swine?

Answer 20

Humans: cysticerci (skeletal muscles), adults (SI)

Swine: cysticerci (skeletal muscles)

Question 21

How do humans get infected by Taenia solis?

How do swine get infected?

Answer 21

Ingestion of hexacanth embryo (which develops to cysticerci) or ingestion of raw or undercooked pork containing cysticerci (which develops to adults)

Ingestion of hexacanth embryo

Question 22

What parasite is known as the swine kidney worm?

What are the 3 modes of infection of this parasite?

Answer 22

Stephanurus dentatus

ingestion of L3, ingestion of P.H. (earthworm) containing L3, skin penetration of L3

Question 23

What causes most of the pathology associated with Stephanurus denatus infection?

Answer 23

migration of larvae through liver and peritoneal cavity, can cause lesions similar to milk spots of Ascaris suum

Question 24

Prevention of Stephanurus dentatus infection?

Treatment options?

Answer 24

Do not raise swine on dirt or pasture

Ivermectin, doramectin, fenbendazole,

Question 25

T/F: Sarcoptic mange in swine is a reportable disease

T/F: Haemotopinus suis is the only biting louse of swine

Answer 25

False, it is not

False, H. suis is a sucking louse, but it is the only sucking louse of swine,