GI Pathology: Esophagus, Forestomachs, Stomach

Cats/ horses

Dogs

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

Cat and dog

What species will not have keratinized esophagus?

Regurge

Emaciation

Dehydration

-Aspiration pneumonia

What are clinical signs of megaesophagus?

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

What is going to cause congenital megaesophagus?

German Shepards

Newfoundland

Great Dane

What breeds are predisposed to congenital megasophagus?

Polymyositis

Myasthenia gravis

Hypothroidism

Lead/ thallium tox

What are some methods of acquired diffuse megaesophagus?

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

Explain the pathogenesis of how Spirocerca lupi will cause esophagitis?

Fibrosarcomas

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

Pressure necrosis leading to perforation of stricture

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

Caustic substances

Viral infections (BVDV)

What are causes of ulcerative esophagitis?

Esophageal stricture

-chronic inflammation/ ulceration leading to fibrosis

Identify the pathology?

Stratified squamous epithelium

What is the rumen forestomach lined with?

-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 is the pathology of ruminal acidosis?

Truperella pyogenes

Fusobacterium necrophorum

-abscesses in the rumen/ liver

What are the most common culprits of bacterial rumenitis?

Aspergillus

Zygomycetes

What are the most common agents in mycotic rumenitis?

Bacterial translocation/ inflammation

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

Frothy bloat - too many legumes

What causes primary bloat?

Physical/ functional obstruction

What causes secondary 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

Explain the pathogenesis of bloat?

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

Identify the pathology?

Mucus - protects epithelium

Mucous cells will secrete:

Hydrochloric acid

Parietal cells secrete:

Pepsin - digestive enzyme

Chief cells secrete:

Hormones - gastrin

Enteroendocrine cells secrete:

Swine

What animal will we find a torus pyloricus?

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

What is the margo plicatus?

Clostridium septicum/ perforinges

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

Hemorrhage

Necrosis

Gas bubbles

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

Common in dogs due to dietary indiscretion

What is chronic gastritis?

Lymphoplasmacytic gastritis

What microscopic findings will you see in chronic gastritis?

Calcification of glands - mineralization of vessels

What will you see in uremic gastritis?

Hemonchus contortus

Ostertagia ostertagi

What gastric parasites seen in ruminants?

Draschia megastoma

What is the most common parasite seen in horses?

Blood sucking nematodes in the abomasum

-severe anemia

-hypoproteinemia

-decreased oncotic pressure

-pale mucus membrane

-effusions

-SQ edema

-Bottle jaw

What signs will you see in hemonchus contortus?

Thickened cobblestone appearance of abomasa mucosa

proliferation of mucosal cells

Eosinophilic gastritis

What are symptoms of ostertagia ostertagi?

Brood pouch - mass like lesions

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

Grain feeds - rapidly growing pigs

What are common causes of gastric ulcerations in pigs?

Mycotic,

Acidosis/ bloat

What are common causes of gastric ulceration in a cow?

Urema

NSAIDS

Paraneoplastic

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

Gastrinomas-gastrin

MCT - histamine

What are two paraneoplastic causes of gastric ulcerations in dogs?

NSAIDS

Stress

What causes gastric ulcers in horses?

Gastroduodenal ulcers - at the pylorus

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

Canine gastric dilation and volvulus (GDV)

- Large breed/ deep chested

Identify the pathology?

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

Explain the pathology of GDV?

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

How dose GDV lead to death?

hyper motility

Displacements in ruminate are common w/ what?

Parturition

Abomasum displacement most commonly occurs after __?

Metabolic alkalosis - chloride sequestration

What will a volvulus lead to in ruminants?

Rupture/ sepsis

What are consequences of gastric ilation/ displacement?

Dog

-Strictures in the stomach

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

Adenocarcinoma?

Horses

-nests/ islands making keratin

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

Squamous cell carcinoma

Cows

Cats

Dogs

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

Lymphoma

Dogs

-non-infultrated

-in the stomach wall

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

Leiomyoma, leiomyosarcoma

Spontaneous

Bovine leukemia virus induced

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