Intestine, Liver, and Pancreas Pathology

What specific specific virus is ubiquitous and targets villus enterocytes?

Rotavirus

Match the age of onset with the species in terms of rotavirus:

1-7 weeks

1 week and older

4 weeks and older

Piglet

Foals

Calves

Calves: 1 week and older

Piglets: 1-7 weeks

Foals: 4 weeks and older

Name the THREE major clinical signs of rotavirus.

1. Dehydration

2. Yellow watery diarrhea

3. Weakness

What TWO types of diarrhea are characteristic of rotavirus?

1. Malabsorptive

2. Hypersecretion (enterotoxic protein)

What would the villi look like in a rotavirus case?

Short, blunted, fused villi

What virus has a similar infection but more severe and prolonged than rotavirus?

Coronavirus

True or False: Coronaviruses affect cattle and horses that are 1 week or older.

True!

What are the THREE major presentations of coronavirus in cattle?

1. Calf diarrhea- malabsorptive yellow diarrhea; dehydration

2. Winter dysentery- mild; generally nonfatal colitis in adults

3. Colitis of Beef Calves- hemorrhagic; can be fatal

True or False: Coronavirus is more severe in horses compared to cattle.

False! Coronavirus is typically MILD and NONFATAL enteritis and diarrhea in horses.

What TWO forms of coronavirus show up in swine and when?

1. Transmissible gastroenteritis (TGE): pigs younger than 10 days

2. Porcine epidemic diarrhea (PED): all ages; more severe younger pigs

What are the clinical signs of PED? (3)

1. Malabsorptive yellow diarrhea

2. Dehydration

3. Vomiting

What disease involves dilated, fluid and gas fluid intestine, and villous atrophy, commonly called "atrophic enteritis?"

Porcine epidemic diarrhea (PED) in swine

What kind of virus is BVDV?

Pestivirus

What FOUR clinical signs are characteristic of classic BVDV?

How old must calves be to get this?

1. Anorexia

2. Oculonasal discharge

3. Mild oral erosions

4. Diarrhea

1 week or older

What FIVE clinical signs are characteristic of severe acute BVDV?

What demographic of cattle is it common in?

1. Sudden death

2. Pneumonia

3. Diarrhea

4. Thrombocytopenia

5. Mucosal erosions

Older animals

If an animal presents with suspected BVDV with pyrexia, anorexia, stomatitis, and severe diarrhea +/- blood and mucus with coronary band lesions, how would you classify it?

Mucosal disease

Mucosal disease BVDV involves —- infected calves, often with ————- exposure to noncytopathic virus and exposure between ——— months to related cytopathic strain.

Persistently

In utero

6-24 months

What is the major pathologic finding of mucosal BVDV?

Peyer's patch necrosis/ulceration

(Also ulcers in mouth/esophagus/rumen/abomasum)

Severe acute inflammation of the mucosa over Peyer's patches, destruction of underlying glands, collapse of lamina propria, and necrosis of lymphoid tissue describes what disease?

Mucosal BVDV

What is a ubiquitous protozoan pathogen that is intracellular but has an extracytoplasmic location?

Cryptosporidium parvum

True or False: C. Parvum is zoonotic.

True! (Hell yeah brother)

What is the major clinical sign of Cryptosporidium parvum infections?

How old are calves that get this?

Self-limiting malabsorptive diarrhea

Day 4-20

True or False: Crypto can be intractable, especially with young or immunocompromised.

True!

What are THREE histopath findings of crypto?

1. Villus atrophy

2. Crypt hyperplasia

3. Organisms

True or False: Crypto lesions are typically localized to the large intestine rather than the distal small intestine.

False! Crypto lesions are typically localized to the DISTAL SMALL INTESTINE rather than the large intestine.

What parasite is host and tissue specific, obligate intracellular, and protozoal in nature?

Coccidia

Name the TWO major types of coccidia in large animals.

1. Eimeria

2. Cystoisospora suis

What does Eimeria spp. cause in sheep/goats and cattle, respectively?

Sheep/goats: multifocal proliferative enteritis

Cattle: necrohemorrhagic enteritis

What does Cystoisospora suis cause in swine?

Fibronecrotic enteritis

In horses, the —- stage larvae of Strongylus vulgaris is associated with ——————————— and intestinal infarction.

4th

Cranial mesenteric arteritis/thrombosis

What does small strongyles (cyathostomes) cause in horses?

What larvae can then emerge from this location?

Necroulcerative hemorrhagic typhlocolitis

4th and 5th stage larvae (cecum + colon)

Match this random list of shit:

Anoplocephala spp in horses and Moniezia in ruminants

Ascaris suum in pigs and Parascaris equorum in horses

Opportunistic ciliate pathogen

Trichuris suis in pigs

Oxyuris equi in horses

Pinworm

Cestodes

Balantidium coli

Trichuriasis

Ascarids

Balantidium coli: opportunistic ciliate pathogen

Cestodes: Anoplocephala spp in horses and Moniezia in ruminants

Ascarids: Ascaris suum in pigs and Parascaris equorum in horses

Trichiuriasis: Trichuris suis in pigs

Pinworm: Oxyuris equi

True or False: More than one concurrent disease causing diarrhea is common and can complicate diagnosis.

True!

What do we commonly call hemorrhagic fibronecrotic duodenitis-proximal jejunitis in horses?

Anterior enteritis (duodenitis-proximal jejunitis)

Although the cause is unknown, what is thought to be a potential reason for anterior enteritis?

Salmonella or Clostridium infection

What disease involves equine intestine does not have an identified cause, but is associated with exhaustion, stress, C. Perf A or C, C. Diff, and diet?

Colitis X

What is the major clinical sign of colitis X?

What THREE pathology findings are there?

Rapidly fatal nonhemorrhagic diarrhea

1. Cecal/colonic edema

2. Congestion

3. Hemorrhage

Name FOUR major toxicants of the intestine.

1. Bracken fern

2. Phosphorus/nitrate/thallium

3. Arsenic/copper/mercury

4. Blister beetles

What unique byproduct do blister beetles release, causing acute necrohemorrhagic enteritis?

Cantharidin

In terms of neoplasia, —- is common in cattle and sheep, yet rarely seen in pigs.

—- is commonly seen in horses and cattle.

—- are seen in horses.

Adenocarcinoma

Lymphoma

GIST (Gastrointestinal stromal tumor)

What occurs in the liver of horses and cattle where there are pale areas adjacent to a capsular adhesion?

Tension lipidosis

What is the pathogenesis of tension lipidosis? (3)

Reduced blood supply -> degeneration -> lipidosis

What commonly occur in the liver of the horse where fibrous tags or plaques are found on the diaphragmatic surface?

Capsular fibrosis

Although there is no cause known for capsular fibrosis, what was it previously linked to?

Larval nematode migrations

What liver condition involves cystic dilation of the sinusoids?

What species is it common in?

Telangiectasia

Cattle (no clinical significance)

True or False: Telangiectasia involves evidence of intense inflammation and fibrosis of the liver.

False! There is NO evidence of inflammation or fibrosis with telangiectasia.

What are the major causes of hepatic lipidosis in pigs, sheep/goats, cattle, and horses, respectively?

Pigs: dietary excess

Sheep/goats: dietary deficiency of cobalt/vitamin B12; ketosis

Cattle: ketosis; bovine fatty liver syndrome

Horses: hyperlipidemic; overweight/pregnant/lactating pony/mini

True or False: In general, hepatic lipidosis is more common in pregnant and lactating animals.

True!

What TWO major things are associated with bacterial hepatitis?

1. Abscesses

2. Granulomas

What are the FOUR major routes of bacterial hepatitis?

1. Hematogenous

2. Ascending from biiary tract

3. Parasite migration

4. Direct extension

Name FOUR bacterial causes of bacterial hepatitis, both Gram-positive and negative.

1. Fusobacterium necrophorum (rumen acidosis)

2. Corynebacterium pseudotuberculosis

3. Rhodococcus equi

4. Trueperella pyogenes

Name TWO acid-fast bacterial causes of bacterial hepatitis.

1. Mycobacterium bovis

2. Mycobactrium avium subspecies paratuberculosis

True or False: Fungal disease, like mucormycosis, can also cause hepatitis.

True!

What are the THREE major consequences of abscesses/granulomas caused by bacterial hepatitis?

1. Incidental

2. Rupture -> septic embolization

3. Phlebitis and thrombosis -> septic thromboembolism

Name at least FOUR bacterial causes of multifocal, random necrotizing manifestations of bacterial hepatitis.

1. Campylobacter fetus subspecies fetus

2. Actinobacillus equuli

3. Salmonella spp

4. Listeria monocytogenes

5. Brucella spp

What causes Tyzzer's disease?

What animal is it most commonly seen in?

Clostridium piliforme

Foals

What are the pathologic findings that could indicate Tyzzer's disease?

What stain is often used to confirm?

1. Random necrotizing hepatitis

2. Intracellular bacilli

Warthin-Starry or GMS silver stains

—-virus hates babies

Herpes

What is the major clinical sign of herpesvirus infections across species?

What TWO pathologic findings would be expected?

Disseminated viral infection

1. Multifocal

2. Random hepatic necrosis

What is the disease associated with injection of equine serum biologic that has been linked to equine parvovirus?

Theiler's disease

What are the FOUR major clinical signs of Theiler's disease?

1. Liver failure

2. Hepatic encephalopathy

3. Icterus

4. Photosensitization

What would you expect to find on pathology with Theiler's disease?

Small, flabby (dishrag) liver with lobular pattern (centrilobular to massive necrosis)

What nematode is typically responsible for larval migration to the liver, especially horses and pigs?

Ascarids

What parasite is associated with milk spot liver?

Ascaris suum

Whaat is the pathologic difference between acute and chronic ascarid larval migration?

Acute: tracts of inflammation and hepatocellular necrosis

Chronic: fibrous tracts

What is the major cestode associated with larval migration of the liver?

Cysticercus tenuicollis (Taenia hydatigena)

What liver fluke migrates through the intestine into the liver and causes adult to live in the biliary system and are associated with tracts of hemorrhage, necrosis, and parasitic hematin that repairs with fibrosis?

Fasciola hepatca

Fasciola hepatica causes what TWO major things in adults?

1. Biliary ectasia

2. Fibrosis

What liver fluke involves immature flukes migrating through the intestine and the liver and continues to migrate or become encysted in a fibrous capsule?

Fascioloides magna

True or False: Fascioloides magna involves tracts of hemorrhage, necrosis, and parasitic hematin, which repairs by fibrosis.

True!

Migrating liver flukes can activate —- spores.

Clostridial

What spore is associated with bacillary hemoglobinuria?

What THREE things does its exotoxins cause?

Clostridium haemolyticum

1. Hepatic necrosis

2. Intravascular hemolytic anemia

3. Hemoglobinuria

What spore is associated with infectious necrotic hepatitis/Black disease?

Clostridium novyi

True or False: The exotoxins of Clostridium novyi cause hepatic necrosis and a less prominent hemolysis.

True!

Name at least TWO examples of pyrrolizidine alkaloid-containing plants.

1. Senecia

2. Cynoglossum

3. Amsinckia

4. Crotalaria

5. Echium

6. Trichodesma

7. Heliotropium

Liver toxicosis is commonly caused by alkaloids. Alkaloids are metabolized by —- to a reactive intermediate -> binds —- and —- —- -> cell —- and DNA —- mutations leading to —-.

P450

Proteins

Nucleic acid

Death

Mutation

Neoplasia

Order the following from greatest to least in terms of liver toxicosis by susceptibility:

Sheep/goats

Pigs

Cattle/horses

Pigs > Cattle/horses > sheep/goats

Name the FOUR major pathologic changes associated with liver toxicosis.

1. Hepatic fibrosis

2. Megalocytosis

3. Ductular reaction

4. Regeneration

What mycotoxin is associated with hepatoxic and carcinogenic effects, commonly impacting young pigs, horses, and cattle?

Alfatoxin B1 (Aspergillus flavus)

True or False: Acute intoxication of alfatoxin B1 is more common in young pigs, horses, and cattle.

False! CHRONIC intoxication of alfatoxin B1 is more common in young pigs, horses, and cattle.

What are the TWO major clinical signs of mycotoxins?

1. Ill-thrift

2. Hepatic failure

What are the FOUR pathologic findings of mycotoxins in the liver?

1. Hepatocellular degeneration/necrosis

2. Ductular reaction

3. Centrilobular to bridging fibrosis

4. Megalocytosis

What species have reduced biliary excretion of copper?

Sheep

What TWO things cause chronic copper toxicosis?

1. Dietary copper excess

2. Molybdenum insufficiency

What releases stored copper from the liver?

Hepatocellular injury (often a toxicant)

What are the THREE clinical signs of chronic copper toxicosis?

1. Acute intravascular hemolysis

2. Icterus

3. Hemoglobinuria

What are the TWO major pathologic findings of chronic copper toxicosis?

1. Orange liver

2. Chronic hepatitis

What should you do if you see a liver you're worried about chronic copper toxicosis?

Submit KIDNEY for copper analysis

What is hepatosis dietetica associated with?

Vitamin E/Selenium deficiency in pigs

What is the major pathologic finding of hepatosis dietetica?

Centrilobular to massive hepatic necrosis

What neoplasias are most common in ruminants?

Hepatocellular adenomas and carcinomas

What neoplasia occurs in all large animal species?

Cholangiocellular carcinoma

(Benign/malignant/metastatic) neoplasia is very common and —- is the most common.

Metastatic

Lymphoma

What is common in ruminants and is usually incidental but can obstruct extrahepatic bile duct?

Choleliths

What unique disease is seen in cattle caused by Salmonella dublin?

Fibrinous cholecystis

True or False: Pancreatic disease is very common in large animals.

False! Pancreatic disease is very RARE in large animals

What pancreatic disease is uncommon in cattle older than 4 years, usually incidental?

Pancreatic calculi (pancreolithiasis)

What pancreatic condition is sporadic in the horse and is linked to Strongylus spp. larval migration or ascending bacterial infection?

Chronic pancreatitis

What are the TWO main pathologic findings of chronic pancreatitis?

1. Enlarged fibrotic pancreas

2. Dilated ducts

What pancreatic condition is sporadic in calves?

Pancreatic hypoplasia