Gross Pathology of Swine 1

Question 1

Most common heart defects

Answer 1

Valvular dysplasia
High ventricular septal defect

Question 2

Differential list for myocardial necrosis (white spots on heart)

Answer 2

Pseudorabies (suid herpesvirus 1)
Encephalomyocarditis virus (picornavirus)
Foot and mouth disease (aphthovirus)- sucklings

Question 3

Gross signs of polyserositis

Answer 3

Fibrin (vasculitis) in pericardium, chest, abdomen, joints, meninges

Question 4

Causes of polyserositis (3)

Answer 4

Streptococcus suis type 2
Mycoplasma hyorhinus
Glasserella parasuis

Question 5

Four causes of vegetative valvular endocarditis

Answer 5

Streptococcus suis type 2
Staphylococcus aureus
Coliform (e.coli, salmonella, trueperella, etc.)
Erysipelothrix rhusiopathiae

Question 6

What does a Vitamin E/Selenium imbalance cause in the pig?

Answer 6

Mulberry heart disease aka Dietetic microangiopathy

Question 7

What is the pathogenesis of mulberry heart disease?

Answer 7

Vit E and Selenium don’t prevent oxidation–> fibrinoid vasculitis and hemorrhage due to systemic arterial degeneration–>ischemic necrosis of myocardium (no direct damage to myofibrils)

Question 8

Gross signs with mulberry heart disease

Answer 8

Myocardial necrosis- classically, ton of hemorrhage around bulging/dilated RV
Arteriolar necrosis in multiple organs

Question 9

Age group most often affected by Mulberry heart disease

Answer 9

Weaners

Question 10

Other organs that will be affected by mulberry heart disease

Answer 10

Brain
Liver
Lungs

Question 11

Differentials for fibrinous pericardial effusion (3)

Answer 11

Mulberry heart disease
Edema disease (shiga producing E.Coli)

Question 12

Mechanism in gossypol toxicity (from cotton seed meal)

Answer 12

Heart- we don’t know, but they die of heart failure
Liver- uses up glutathione

Question 13

Gross lesion with gossypol toxicity in the heart

Answer 13

Pericardial effusion

Question 14

Differentials for nasal discharge

Answer 14

Polyserositis (glasser’s disease, strep suis, mycoplasma hyorhinus)
Inclusion body rhinitis
Pseudorabies in young piglet

Question 15

Gross lesion with inclusion body rhinitis

Answer 15

Catarrhal rhinitis

Question 16

Cause(s) of atrophic rhinitis

Answer 16

Nonprogressive- B bronchiseptica
Progressive- B bronchiseptica and P multocida (type D toxin producing)

Question 17

What does necrotic rhinitis look like, vs. atrophic rhinitis

Answer 17

Necrotic rhinitis- bullnose (issue lateral to turbinates), caused by F necrophorum
Atrophic rhinitis- deviation of snout and porphyrin staining (turbinates gone)

Question 18

Respiratory signs with pseudorabies

Answer 18

Age dependent:
No problems in adults
Grower-finisher- respiratory disease (lung spots of necrosis)
Pigs 2 weeks old or less- necrotizing rhinotracheitis, then hemorrhagic meningoencephalitis

Question 19

Cause of tracheal hemorrhage

Answer 19

Actinobacillus pleuropneumoniae or suis
Swine influenza

Question 20

Cause of checkerboard pneumonia with depressed necrotic areas in swine

Answer 20

Swine influenza virus (epithelial necrosis)

Question 21

Cause of enlarged lungs without checkerboard pattern (2)

Answer 21

Porcine circovirus type 2 or Porcine arterivirus (PRRS)

Question 22

Morph for porcine circovirus type 2 or PRRS

Answer 22

Granulomatous bronchointerstitial pneumonia

Question 23

Classic bronchopneumonia cause with sharp demarcation between normal and abnormal

Answer 23

Mycoplasma hyopneumoniae (enzootic pneumonia)

Question 24

Shipping fever of pigs; how to tell from other pneumonias?

Answer 24

Actinobacillus pleuropneumoniae or suis; looks as bad as it can get, lots of fibrin, oat cells

Question 25

Cause of embolic pneumonia (sepsis) (2)

Answer 25

Erysipelothrix rhusiopathiae Salmonella cholerasuis or typhisuis

Question 26

Cause of large greenish nodules in lungs with areas of hyperinflation

Answer 26

Metastrongyles: Metastrongylus apri

Question 27

Cause of areas of hemorrhage and necrosis scattered throughout all lung lobules, with lots of eosinophils

Answer 27

Ascaris suum larval migration

Question 28

Cause of diffuse lung edema and hydrothorax (toxic)

Answer 28

Fumonisin (moldy corn poisoning) Fumonisin B1- also causes pancreatic necrosis, damages alveolar endothelium

Question 29

Cause of hemorrhage in tonsillar tissue

Answer 29

Classical swine fever

Question 30

Other gross signs with CSF

Answer 30

Splenic infarcts at margins Hemorrhage at periphery of lymph node (medullary sinuses)

Question 31

Cause of diffusely hemorrhagic lymph nodes

Answer 31

African swine fever

Question 32

Cause of tonsillar necrosis

Answer 32

Pseudorabies

Question 33

Cause of generalized lymphadenopathy; key histo

Answer 33

Porcine circovirus 2; granulomatous inflammation with botryoid intracytoplasmic viral IBs in macs

Question 34

Morph with PCV2 in lymph nodes

Answer 34

Granulomatous lymphadenitis with botryoid inclusions

Question 35

Other differential for granulomatous lymphadenitis

Answer 35

Mycobacterium avium (mostly historical, so always pick PCV2)

Question 36

Cause of enlarged, orange lymph nodes

Answer 36

Iron supplementation (normal)

Question 37

Cause of enlarged spleen

Answer 37

Mycoplasma suis (extravascular hemolysis, no icterus)

Question 38

Cause of ulcers on lips and gingiva

Answer 38

Mycotoxin (tricothecene) from Fusarium spp.

Question 39

What causes edema disease?****

Answer 39

Shiga toxin producing E.Coli

Question 40

Gross signs with edema disease

Answer 40

Larynx, brain, stomach, mesocolon

Question 41

Differentials for gastrointestinal venous infarcts (4)

Answer 41

Salmonella cholerasuis (sepsis) Post-weaning colibacillosis Erysipelothrix Sepsis

Question 42

What does mycobacterium avium do in the pig?

Answer 42

Hemolymphatic, GI

Question 43

Parasite of GI that causes proliferation, but does not invade mucosa

Answer 43

Hyostrongylus rubidus

Question 44

Cause of congested intestines full of orange/brown fluid in neonates

Answer 44

ETEC

Question 45

Differentials for see-through intestines full of clear fluid in young pigs

Answer 45

Coronavirus: Transmissible gastroenteritis Porcine epidemic diarrhea virus Rotavirus

Question 46

Cause of mesocolon edema in neonates? Weaner?*****

Answer 46

Clostridium dificile in neonates Edema disease if older

Question 47

Cause of segmental necrohemorrhagic enteritis with gas production in young piglets

Answer 47

Clostridium perfringens type C

Question 48

Cause of proliferative enteritis

Answer 48

Lawsonia intracellularis

Question 49

Three patterns of lawsonia intracellularis

Answer 49

1. Proliferative enteritis- cerebriform folds 2. Hemorrhagic bowel syndrome- blood in lumen 3. Necrotic enteritis/ileitis- fibrinonecrotic membrane

Question 50

Host adapted Salmonella strains; disease caused?

Answer 50

cholerasuis and typhisuis; sepsis, thrombosis, edema, cyanosis, button ulcers in colon

Question 51

Non host-adapted Salmonella strain; disease caused?

Answer 51

typhimurium; diffuse mucosal necrosis in all GI

Question 52

Gross lesions seen with C. dificile

Answer 52

Mesocolon edema Volcano ulcers, button ulcers

Question 53

Differentials for necrotic enteritis

Answer 53

Salmonella typhimurium Lawsonia intracellularis (does not affect colon) Classical swine fever (pestivirus) Brachyspira hyodysenteriae (swine dysentery)

Question 54

What part of GI do ascarids like?

Answer 54

Duodenum

Question 55

Cause of hemorrhagic or fibrinonecrotic colitis in spiral colon****

Answer 55

Brachyspira hyodysenteriae- swine dysentery

Question 56

Parasite of GI that DOES embed in mucosa

Answer 56

Trichuris suis, will see long worms with hemorrhage