Pathology of Alimentary Tract 2 (Ruminant Forestomachs/ Glandular stomach)

melian.yates
Mind Map by , created over 5 years ago

Doctorate Pathology (Systems Pathology) Mind Map on Pathology of Alimentary Tract 2 (Ruminant Forestomachs/ Glandular stomach), created by melian.yates on 12/05/2013.

1009
2
0
Tags
melian.yates
Created by melian.yates over 5 years ago
patho. practical slides
أطباء2020
Pancreas Pathology
melian.yates
Endocrine Pathology
melian.yates
Sociology - Crime and Deviance - Feminists
josaul1996
4. The Skeletal System - bones of the skull
t.whittingham
Musculoskeletal Pathology
melian.yates
Liver Pathology
melian.yates
General Pathoanatomy Final MCQs (301-400)- 3rd Year- PMU
Med Student
General Pathoanatomy Final MCQs (401-519)- 3rd Year- PMU
Med Student
General Pathoanatomy Final MCQs (201-300)- 3rd Year- PMU
Med Student
Pathology of Alimentary Tract 2 (Ruminant Forestomachs/ Glandular stomach)
1 Ruminant Forestomachs
1.1 Forestomachs: Rumen, Reticulum, Omasum
1.2 Note: Postmortem putrfactive changes occur rapidly (Gas distension, Sloughing of mucosa)
1.3 Functional Disorders
1.3.1 Bloat (Ruminal Tympany)
1.3.1.1 Failure to expel fermentation gases
1.3.1.2 Pathogenesis:
1.3.1.2.1 Primary:
1.3.1.2.1.1 "Frothy bloat"
1.3.1.2.1.2 Due to formation of stable foam in Rumen (follows ingestion of excess high protein lucerne/clover or high concentrate, low roughage diet
1.3.1.2.2 Secondary:
1.3.1.2.2.1 Mechanical/functional obstruction of oesophagus (oesophageal stricture) -> accumulation of gas
1.3.1.2.2.1.1 Vagus indigestion (Traumatic reticuloperitonitis, liver abscess, chronic suppurative bronchopneumonia)
1.3.1.2.2.1.1.1 Recurrent laryngeal nerve & Vagus nerve => Vagal function => Reduced Rumen Motility
1.3.1.2.2.1.2 Neoplasia (Lymphoarcoma, Papillomas)
1.3.1.3 Overdistension of Rumen & Reticulum with fermentative gases
1.3.1.3.1 Increased intra-abdominal pressure
1.3.1.3.1.1 Congestive heart failure
1.3.1.3.1.1.1 Compression of diaphragm
1.3.1.3.1.1.1.1 Resp. failure
1.3.1.3.1.1.1.1.1 "Bloat line" cranial to thoracic inlet
1.3.1.3.1.2 Reduced return of blood flow to heart
1.3.1.3.1.3 Blood is dark (Hypoxic) & clots poorly
1.3.1.3.1.3.1 Congestion, Oedema & subcutaneous haemorrhage of head & neck tissues
1.3.2 Runminal Acidosis (Grain overload)
1.3.2.1 Ruminitis may develop => allow thromboemboli to travel to the Liver => Hepatic abcessation
1.3.2.1.1 Histologically: Microvesicles containing mainly neutrophils occur in the epithelium of the rumen papillae
1.3.2.1.1.1 May be focal erosions/ulcerations
1.3.2.1.1.1.1 Damaged mucosa may be colonized by fungi (e.g. Mucor/Rhizopus/Absidia app.) or bacteria (e.g. Fusobacterium necrophorum)
1.4 Inflammation
1.4.1 Traumatic Reticulitis "Hardware disease"
1.4.1.1 Ingestion of sharp objects (e.g. wire, nails)
1.4.1.2 1) Fall to floor or reticulum => Insignificant
1.4.1.3 2) Contractions force foreign body into wall of reticulum:
1.4.1.3.1 => Mild suppurative or Granulomatous reticulitis +/- Peritonitis
1.4.1.3.1.1 Localized => Adhesions
1.4.1.4 3) Foreign body penetrates Cranial wall (rumen contractions) :
1.4.1.4.1 => Acute Peritonitis, Local Fibrous adhesions
1.4.1.4.1.1 => Penetrates Diaphragm (Fibrinopurelent pleurisy, pneumonia, pericarditis)
1.4.1.4.1.1.1 Fusobacterium, Actinomyces spp.
1.4.1.5 Inflammatory process around Reticulum (may) => vagus indeigestion & ruminal stasis
1.4.1.6 => Purulent fluid build up => Cardiac Failure
1.4.2 Ruminitis (Bacterial or Mycotic)
1.4.2.1 Bacterial
1.4.2.1.1 Lactic Acidosis
1.4.2.1.1.1 Opportunistic pathogens (Take advantage of acidotic lesions & other disturbances of rumen flora)
1.4.2.1.2 Mechanical Injury to Rumen
1.4.2.1.2.1 Ex. Traumatic Reticuloperitinitis
1.4.2.1.2.2 Damage to Rumen wall => Infiltration of bacteria (GI colonizers)
1.4.2.1.3 Fusobacterium necrophorum, Trueperella pyogenes, Actinobacillus lignieresii
1.4.2.2 Mycotic
1.4.2.2.1 Abx, Lactic Acidosis
1.4.2.2.2 Vascular invasion -> Thrombosis -> Infarction
1.4.2.2.3 Haematogenous -> Placentitis -> Abortion
1.4.2.2.4 Mucor/Rhizopus/Absidia
1.4.2.3 Gross: Multiple, dark red areas of swollen paillae, Coagulative necrosis of papillae, Serofibrinous exudate
1.4.2.4 Histologically: Coagulative necrosis of papillae, marked neutrophil infiltrate
1.4.2.5 Thromboembolic spread => Form areas of coagulative necrosis & abscesses in Liver
1.5 Neoplasia
1.5.1 Papillomatosis
1.5.1.1 Bovine papillomavirus type 4
1.5.1.2 Usually pedunculated structures in Reticulum/Rumen of Cattle
1.5.2 Squamous cell carcinoma
1.5.2.1 Thought to develop from papillomas in Cattle in association with ingested carcinogens in Bracken Fern
2 Pathology of the Glandular Stomach & Abomasum
2.1 Physical Disturbances
2.1.1 Obstruction
2.1.1.1 Foreign body
2.1.1.1.1 Bones, stones, hair/wool balls (trichobezoars), plant material (phytobezoars)
2.1.1.2 Pyloric Stenosis
2.1.1.2.1 Dogs, Foals, Cats
2.1.1.2.2 Congenital Hypertrophy of Pyloric muscle
2.1.1.2.2.1 => Delayed Gastric emptying & persistent vomiting/regurgitation
2.1.1.2.3 Acquired
2.1.1.2.3.1 Following healed ulcers (foals)
2.1.1.3 Functional Obstruction
2.1.1.3.1 Dysautonomia
2.1.1.3.1.1 Feline dysautonomia
2.1.1.3.1.2 Equine Grass sickness
2.1.1.3.2 Vagal indigestion (Cattle)
2.1.1.3.3 End-stage liver disease (Equine)
2.1.1.4 Horses DON'T vomit! Stomach will rupture before they vomit
2.1.2 Displacements of the stomach/abomasum
2.1.2.1 Herniation of Stomach (through diaphragm)
2.1.2.1.1 Congenital (Cats)
2.1.2.1.1.1 Often associated w/ herniation of Liver
2.1.2.1.1.1.1 Peritoneo-pericardial diaphragmatic hernia
2.1.2.1.2 Acquired (Dogs, Cats)
2.1.2.1.2.1 RTAs
2.1.2.1.2.1.1 Displacement of GI tract into peritoneal cavity
2.1.2.2 Abomasal Displacement (Cattle)
2.1.2.2.1 Ventral & to left of Rumen (LDA)
2.1.2.2.1.1 85% of Displacements
2.1.2.2.1.2 Partial obstruction of outflow
2.1.2.2.1.2.1 Mild consequences: May not require surgery
2.1.2.2.2 To right of Rumen (RDA)
2.1.2.2.2.1 15% of Displacements
2.1.2.2.2.2 Acute dilation & volvulus
2.1.2.2.2.2.1 Severe consequences: Usually require surgery
2.1.2.2.2.2.2 Obstructs outflow from abomasum
2.1.2.2.3 Normal location: Close to or just right of the ventral midline
2.1.2.2.4 Constriction of blood vessels & trauma to vagus nerve resulting in abomasal distension w/ blood-stained fluid & gas, congested mucosa, infarction
2.1.2.2.4.1 May rupture => Peritonitis, shock, death
2.1.2.2.4.1.1 NOTE: Gastric rupture may be a PM event due to putrefactive gases (Look for evidence of haemorrhage & Peritonitis suggesting antemortem rupture
2.1.2.2.5 Predisposing factors:
2.1.2.2.5.1 Post-parturient Dairy Cows
2.1.2.2.5.1.1 Change to grain concentrates in diet (Increased VFAs -> Affect motility)
2.1.2.2.5.1.1.1 Hypocalcaemia (Abomasal atony)
2.2 Inflammation
2.2.1 Haemorrhagic/necrotizing Abomasitis
2.2.1.1 Braxy
2.2.1.1.1 Sheep/Cattle
2.2.1.1.2 Acute abomastitis (Red, thickend, necrotic haemorrhagic mucosa
2.2.1.1.2.1 Ingestion of frozen food in winter
2.2.1.1.2.1.1 Devitalizes gastric mucosa
2.2.1.1.2.2 Coagulative necrosis of mucosa & deeper structures w/ fibrin, oedema, haemorrhage & sometimes submucosal emphysema
2.2.1.1.3 Clostridium septicum (Exotoxin)
2.2.2 Bacterial Gastritis & Gastric Ulceration
2.2.2.1 Heliobacteriosis
2.2.2.1.1 Dogs, Cats
2.2.2.1.2 Helicobacter heilmannii, Helicobacter felis
2.2.2.1.3 Chronic mucoid gastritis
2.2.3 Hypertrophic Gastritis/ Abomastitis
2.2.3.1 Chronic hypertrophic gastritis (Dogs)
2.2.3.1.1 Chronic retention of gastric fluid & bile reflux
2.2.3.1.2 Marked mucosal thickening & convolution of rugae
2.2.3.1.2.1 Histologically: Marked epithelial hyperplasia, loss of parietal/chief cells, dilation of mucous glands & mixed inflammatory cell infiltrates in lamina propria
2.2.3.2 Parasitic Gastritis (Osteragiosis)
2.2.3.2.1 Cattle: Ostertagia ostertagi
2.2.3.2.1.1 Sheep: Teladorsagia circumcincta
2.2.3.2.2 Acute Gastritis
2.2.3.2.2.1 Hyperaemia & oedema
2.2.3.2.3 Chronic Gastritis
2.2.3.2.3.1 Nodules (encysted larvae) in abomasal mucosa, "Morocco leather" appearence
2.2.3.2.4 Glandular hyperplasia, loss of parietal/chief cells, chronic inflammation associated w/ lymphocytes, plasma cells & eosinophils & larvae
2.2.4 Chronic Atrophic Gastritis (Dogs)
2.2.4.1 Aetiology uncertain
2.2.4.1.1 Mucosal thinning & loss of gastric glands, diffuse mixed inflammtory infiltrate in the lamina propria
2.3 Ulceration
2.3.1 Pathogenesis
2.3.1.1 Hypersecretion of acid &/or impaired mucosal barrier
2.3.1.1.1 => Mucosal barrier is disrupted -> Pepsin & acid cause Necrosis -> Erosion/ulcers (Erosion of underlying blood vessels -> Haemorrhage
2.3.1.2 Causes:
2.3.1.2.1 NSAIDs
2.3.1.2.1.1 Corticosteroids (Stress)
2.3.1.2.1.1.1 Viral infection (e.g. mucosal disease)
2.3.1.2.1.1.1.1 Foreign bodies
2.3.1.2.1.1.1.1.1 Intestinal obstruction (reflux of bile)
2.3.1.2.1.1.1.1.1.1 Neoplasia
2.3.1.2.1.1.1.1.1.1.1 Idiopathic
2.3.1.2.1.1.1.1.1.1.1.1 (Local Trauma)
2.3.1.2.1.1.1.1.1.1.1.1.1 (Local Ischaemia)
2.3.2 Dogs: NSAIDs, Mast cell tumor (Histamine => HCl hypersecretion), Pancreatic gastrinoma (Tumor derived from Islets -Pancreas -> Gastrin) Azotaemia, Cirrhosis, Bile reflux
2.3.3 Pigs (weaned growers & feeders): Finely ground grain concentrate diets - stratified squamous areas of stomach affected
2.3.4 Horses: Stress/ NSAIDs - stratified squamous epithelium at margo plicatus (adults & foals), glandular area (foals)
2.3.5 Cattle: Periparturient lactic acidosis, Abomasal impaction, displacement or torsion, Mucosal disease - Bleed & perforation
2.3.6 Heal by granulation & fibrosis or perforate
2.4 Neoplasia
2.4.1 Adenocarcinoma
2.4.1.1 Malignancy of mucosal epithelium
2.4.1.2 Most common gastric neoplasm in Small animals
2.4.1.3 Locally aggressive & spreads via lymphatic vessels to lymph nodes, lung, liver
2.4.1.4 Thickened, pale tissue, ulcerated of fungating
2.4.2 Squamous cell carcinoma
2.4.2.1 Commonest gastric tumor in Horses
2.4.2.2 Large cauliflower-like mass
2.4.2.2.1 Metastases & transcoelomic spread
2.4.3 Leiomyoma/Leiomyosarcoma
2.4.3.1 Smooth muscle neoplasms forming nodular masses
2.4.3.2 Mainly Dogs
2.4.4 Lymphoma
2.4.4.1 Diffuse infiltration of Neoplastic lymphocytes
2.4.4.2 Dogs, Cats, Horses