S6 L2- Esophagus, forestomach and stomach | Quizlet

What is Esophageal ectasia, the mechanism behind it and its causes

=Dilatation of the oesophagus & weakening of it’s wall

• Mechanism= Achalasia- uncoordinated esophageal peristalsis w abnormal function of lower and upper sphincter

• Caused by

- denervation

- innervation disorders

- physical obstruction

-Idiopathic

Megaesophagus- 2 forms

1. Congenital

2.Acquired

1. Congenital Megaesophagus

=Partial Block of the lumen by persistent right aortic arch (common in German shep, irish setter, greyhound) or idiopathic denervation (common in great dane, irish setter, labrador etc)

2. Acquired Megaesophagus

=Dilation of oesophagus due to failure of relaxation of the lower sphincter

• Caused by idiopathy, hypothyroidism, esophagitis, chronic gastric dilatation, polymyositis, myasthenia gravis

Esophagitis, Oesophageal erosions, ulcerations are caused by and their PM

CAUSES

• Reflux of gastric acid

• viral infections

• Iatrogenic

• irritant ingestion

PM

• Hyperemia

• Exudate

• Inflammatory infiltrate

• Presence of erosions and ulcers

• Hyperplasia of unaffected areas

Where are Foreign objects mostly found in the GIT and what are their consequences

Mostly in segments that can't fully expand eg. Dorsal to the larynx, thoracic inlet, base of cardia, diaphragmatic hiatus

Caused by bones, potatoes, apples, corn, stones

CONSEQUENCES

1. Choke- AKA esophageal obstruction due to stenosis or blockage

2. Necrosis of esophageal wall

- Pressure mucosal necrosis

- stricture formation after necrosis healing

- esophageal perforation/ inflammation of mediastinum

Clinical Manifestation of esophageal neoplasia

Very rare, common in older patients (SCC and saarcomas)

- weight loss

- painful swallowing - Regurgitation of undigested food

- Dysphagia

- 2ndary aspiration pneumonia

- sometimes complete esophageal obstruction

Ruminal bloat is?

over-distention of rumen & reticulum by gases produced during fermentation

Describe primary and secondary bloat

1. Dietary bloat- overproduction of stable foam

2. Cause by physical or functional obstruction or stenosis of oesophagus resulting in failure to eructate (tumours, FB, innervation disorders)

Mechanism of bloat

• Severe distension of rumen w fermentation gases

• Compression of Diaphragm, lungs, increased intrathoracic pressure

• Decrease in venous return to heart

• Generalised congestion cranial to the thorax inlet

• Death (50% of cases)

PM of bloat

Bloat line → most reliable post mortem indicator of antemortem bloat

- Sharp line of demarcation b/w the pale, bloodless distal esopahgus and congested proximal esophagus at thoracic inlet.

Rumenitis is most commonly associated with and its PM

Lactic acidosis

Grain overload → rumen overload → carb engorgement → chemical rumenitis

PM

-Watery and acidic ruminal and intestinal contents

-Often abdundant grain in rumen

-Mucosa= brown and friable, detaches easily

-Hydropic changes and coagulative necrosis of luminal epithelium - neutrophilic infiltration

-Pale scars formed

Pathology of the stomach: structure, function, defence mechanism

Structure:

→ mucosal membrane:

- Non glandular part (rats, Eq, Su) proximal area around cardia lined by SSE

- Fundus and body → lined by glandular epithelium that secretes gastric acid and pepsin.

- Pyloric region → lined by glandular epithelium that secretes mucus, gastrin and other hormones.

Function:

- Enzymatic and hydrolytic digestion

- Control of GUT activity

Defence mechanism:

- Prevention of autodigestion

- Gastric immune system GALT with IgA-S

- Gastric acid - antibacterial

- Gastric motility and vomiting.

Gastric Dilatation and Volvulus is most common in

dogs esp large deep chested breed + pigs

Causes and PM of Gastric Dilatation and Volvulus

-Distension of stomach w gas, fluid, food

- Obstruction of cardia- prevents eructation and emesis

-Obstruction of Pylorus- prevents passage of gastric contents into S.intestine

-Postprandial (low impact) exercise

-Hereditary predisposition

PM

-Rotation of the stomach clockwise on the vento-dorsal axis (180-360º)

-Displacement of the spleen, torsion & congestion

-Twisted esophagus

Consequence of Gastric Dilatation and Volvulus

• Vascular compression, decreased venous drainage and hypoxia

• Antiperistaltic waves & atony

• Cardiovascular ischemia, arrhythmias and shock and cardiac collapse & death

Gastritis description and cause

acute gastric injury with visible haemorrhage or necrosis, when inflam processes are almost or completely absent.

Causes:

- Foreign objects

- Bacteria, parasites, fungi, viruses

- Irritants, drugs or immune mediated mechanisms (food allergy)

Chronic Giant Hypertrophic Gastropathy occurs in what? what are the clinical consequences? And PM

Occurs in dogs

CS

-weight loss

-vommitting, diarrhea

-Hypoproteinemia

PM

-Folding of mucosal surface that form mass

-Hypertrophy & hyperplasia of mm's

-Variable inflammatory infiltrate

BRADSOT (BRAXXY) description, causative agent, PM

-acute abomatitis of sheep & rarely in calves due to C. septicum

-Occurs in cooler climates

PM

• Bloody abdominal fluid and congestion of abomasal serosa

• abomasal mucosa lesions= diffuse or involve demarcated foci

• Abomasal folds can be thickened, red, hemorrhagic or necrotic

• Hallmark= gelatinous Edema or emphysema of mucosa

Gastric Erosions/Ulcerations cause, clinical manifestations, PM

Cause

-Idiopathic, steroids, uremia, MCT, gastrinoma

Clinical manifestations

-Vomiting, abdominal pain, appetite loss, anaemia

PM

-Numerous lesions up to 5mm

-Mainly in: antral mucosa and proximal duodenum

-Often actively bleeding or covered by clot

Equine Gastric Ulcer Syndrome (EGUS) Causes, clinical manifestation, PM

Cause:

-Decreased bicarb + mucous

-Increased gastric acid, pepsin, bile

-Improper feeding/ circulation

Clinical manifestations:

Poor performance, lack of appetite, chronic colic

PM

-Various no./size of ulcers/ erosions

-Lesions near margo plicatus

-Possible bleeding + perforation

Gastric ulcer in Su cause, clinical manifestation, PM

Cause

-Stressful handling

-High Cu and low protein diet

-Infection with ascaris suum or helicobacter

Clinical manifestations

Acute: anaemia, weakness, inappetence, vomiting, melena (tarry, smelly poo)

Chronic: anorexia, weight-loss, intermittent melena

PM

-Ulcers restricted to pars esophagea

-Parakeratosis

-Ulcer floor covered with necrotic debry or clot

Gastric parasites in horse

Gastrophilus intestinalis

Gastrophilus nasalis

Draschia Megastoma

Gastric parasites in Ru

Hemonchus Contortus

Ostertagia ostertagia

Ostertagia circumcincta

Gastric parasites in pigs

Hyostrongylus rubidus

Gastric Neoplasia name types

1. Epithelial Tumours

2. Leiomyoma

3. Gastric Lymphoma

4. Carcinoma

Gastric Neoplasia rarity & clinically

<1% of all malignancies mostly in smalls adult/older

-Progressive vomitting- hematemesis

-Anorexia

Diagnosed using Xray, USG, gastroscopy, histopathology