GI Pathology: Esophagus, Forestomachs, Stomach

___ and ___ have both skeletal muscle and smooth muscle in their esophagus. __ only have skeletal muscle in their esophagus?

Cats/ horses

Dogs

What species will not have keratinized esophagus?

Cat and dog

What are clinical signs of megaesophagus?

Regurge

Emaciation

Dehydration

-Aspiration pneumonia

What is going to cause congenital megaesophagus?

Persistent R aortic arch - entrapped esophagus leading to segmental dilation cranial to the heart

What breeds are predisposed to congenital megasophagus?

German Shepards

Newfoundland

Great Dane

What are some methods of acquired diffuse megaesophagus?

Polymyositis

Myasthenia gravis

Hypothroidism

Lead/ thallium tox

Explain the pathogenesis of how Spirocerca lupi will cause esophagitis?

Nematode parasites in canines will migrate from stomach -> aorta -> esophagus and will mature in the esophagus wall leading to granulomatous and fibrotic inflammation

What is a possible neoplastic changes that can be seen w/ Spirocerca lupi?

Fibrosarcomas

What are possible sequela of food bolus/ FB in the esophagus?

Pressure necrosis leading to perforation of stricture

What are causes of ulcerative esophagitis?

Caustic substances

Viral infections (BVDV)

Identify the pathology?

Esophageal stricture

-chronic inflammation/ ulceration leading to fibrosis

What is the rumen forestomach lined with?

Stratified squamous epithelium

What is the pathology of ruminal acidosis?

-High grain diet selects for microbes that produce lactic acid.

-Increase of lactic acid lowers pH leading to increased runimal osmotic pressure and hypovolemia

-Circulatory collapse occurs

What are the most common culprits of bacterial rumenitis?

Truperella pyogenes

Fusobacterium necrophorum

-abscesses in the rumen/ liver

What are the most common agents in mycotic rumenitis?

Aspergillus

Zygomycetes

Why does traumatic reticuloperitonitis/ pericarditis cause fibrinous inflammation in the heart/ peritoneum

Bacterial translocation/ inflammation

What causes primary bloat?

Frothy bloat - too many legumes

What causes secondary bloat?

Physical/ functional obstruction

Explain the pathogenesis of bloat?

- Decreased/ lack of eructation

- Gas builds up leading to luminal distension and compression of the diaphragm

- increased intraabdominal and intrathoracic pressure leading to a decreased venous return to the heart

Identify the pathology?

Bloat - (arrow pointing to bloat line where congestion is showing)

Mucous cells will secrete:

Mucus - protects epithelium

Parietal cells secrete:

Hydrochloric acid

Chief cells secrete:

Pepsin - digestive enzyme

Enteroendocrine cells secrete:

Hormones - gastrin

What animal will we find a torus pyloricus?

Swine

What is the margo plicatus?

An equine structure that separates non-glandular stratified squamous stomach to gastric stomach

What agent will kill calves that are 2-6w old after short sings of abdomen distention?

Clostridium septicum/ perforinges

What lesions will you see in the abomasum of calves affected by C. perferingens or septicum?

Hemorrhage

Necrosis

Gas bubbles

What is chronic gastritis?

Common in dogs due to dietary indiscretion

What microscopic findings will you see in chronic gastritis?

Lymphoplasmacytic gastritis

What will you see in uremic gastritis?

Calcification of glands - mineralization of vessels

What gastric parasites seen in ruminants?

Hemonchus contortus

Ostertagia ostertagi

What is the most common parasite seen in horses?

Draschia megastoma

What signs will you see in hemonchus contortus?

Blood sucking nematodes in the abomasum

-severe anemia

-hypoproteinemia

-decreased oncotic pressure

-pale mucus membrane

-effusions

-SQ edema

-Bottle jaw

What are symptoms of ostertagia ostertagi?

Thickened cobblestone appearance of abomasa mucosa

proliferation of mucosal cells

Eosinophilic gastritis

What lesions will we see in a horse affected by Draschia megastoma?

Brood pouch - mass like lesions

What are common causes of gastric ulcerations in pigs?

Grain feeds - rapidly growing pigs

What are common causes of gastric ulceration in a cow?

Mycotic,

Acidosis/ bloat

What are common causes of gastric ulcerations in a a dog?

Urema

NSAIDS

Paraneoplastic

What are two paraneoplastic causes of gastric ulcerations in dogs?

Gastrinomas-gastrin

MCT - histamine

What causes gastric ulcers in horses?

NSAIDS

Stress

Where is the most common location of an ulcer in a dog?

Gastroduodenal ulcers - at the pylorus

Identify the pathology?

Canine gastric dilation and volvulus (GDV)

- Large breed/ deep chested

Explain the pathology of GDV?

Fundus twists and greater curvature is displaced ventrally and duodenum will be moved dorsally and caudally

How dose GDV lead to death?

Decreaed blood flow to heart leading to pulmonary and Cardiovascular depression -> shock/ myocardial dysfunction

Displacements in ruminate are common w/ what?

hyper motility

Abomasum displacement most commonly occurs after __?

Parturition

What will a volvulus lead to in ruminants?

Metabolic alkalosis - chloride sequestration

What are consequences of gastric ilation/ displacement?

Rupture/ sepsis

Name the animal most likely to get the following neoplasia of the stomach:

Adenocarcinoma?

Dog

-Strictures in the stomach

Name the animal most likely to get the following neoplasia of the stomach:

Squamous cell carcinoma

Horses

-nests/ islands making keratin

Name the animal most likely to get the following neoplasia of the stomach:

Lymphoma

Cows

Cats

Dogs

Name the animal most likely to get the following neoplasia of the stomach:

Leiomyoma, leiomyosarcoma

Dogs

-non-infultrated

-in the stomach wall

GI lymphoma in cats is ___ and in cows is ___?

Spontaneous

Bovine leukemia virus induced