Alimentary - Esophagus & Forestomach Flashcards
True/False
The esophagus & forestomachs are lined by simple squamous mucosa
False
Esophagus & forestomachs lined by STRATIFIED SQUAMOUS (non-glandular)!
Abnormal swallowing
Dysphagia
4 phases of swallowing
- Oral
- Pharyngeal
- Crico-esophageal
- Esophageal
2 causes of esophageal dysphagia
- Acquired - PHYSICAL OBSTRUCTION, neuromuscular (myasthenia gravis), endocrinopathy (hypothyroidism)
- Congenital - congenital stricture, K9s predisposed
Causes of physical obstructions of the esophagus
- Impaction (ingesta) / FB
- Muscular hypertrophy (horses) -> prevents expansion
- Strictures (healed ulcers)
- Intra- or Extraluminal mass
Esophageal obstruction sequale
Physical perforation / pressure necrosis -> ulcer -> cellulitis (phlegmon)
True/False
Esophageal strictures can arise from prior ulcers
True
Causes of erosive/ulcerative esophagitis
- Gastic reflux
- Caustic substances (Cantharidin from Blister Beetles)
Diseases of ruminant forestomachs (non-glandular)
Rumen, Reticulum, Omasum
- Rumen tympany
- Traumatic reticulopericarditis
- Rumenitits (viral, rumen acidosis)
True/False
The term “forestomach” actually refers to esophageal dilatations because they are lined by stratified squamous epithelium / are NON-GLANDULAR.
True
Ruminant forestomach with long villi like
“lawn of grass”
Rumen
Ruminant forestomach with
“honeycomb pattern”
Reticulum
Ruminant forestomach with short spikes like
“basketball surface”
Omasum
Ruminant TRUE stomach with slick shiny surface and rugal folds
Abomasum
Lesions seen with ruminant bloat
- Rumen distension (predominantly left sided)
- Head/neck congestion & edema
- Pulmonary atelectasis
- Intraluminal slimy foam or free gas
- Esophageal bloat line
3 Syndromes of Bovine Hardware Disease
- Reticuloperitonitis
- Reticulopleuritis
- Reticulopericarditis
Can occur in combination
Hardware disease sequale
Ingestion of metallic foreign bodies
-> transmural perforation of reticulum
-> perf of diaphragm, pleural cavity, pericardial sac
-> rumen leakage
-> septic peritonitis
-> pleuritis, pericarditis
Clinical signs of Hardware Disease
Peritonitis
* focal = walled-off abscess
* severe = inappetence, dysmotility, distension
Pericarditis/Pleuritis
* inappetence, cranial abdomen/thoracic pain, grunt
* jugular vein distension, head/neck edema, cardiac insufficiency
* Washing Machine Murmur (from anaerobes)
* cardiac tamponade
* characteristic ultrasonographic features
- Ulcerative & inflammatory disease of the rumen
- Caused by unaccustomed ingestion of too much concentrate feed
- Reduced saliva production
Chemical Rumenitis
* aka Rumen Acidosis Syndrome
* Grain Overload
* Rumen Drinkers
Rumen acidosis pathogenesis
Rapid fermentation of CHO
-> excess productino of VFA (acetate)
-> microflora shift (increased lactobacillus & streptococcus, decreased ciliated protozoa & gram-)
-> decreased rumen pH (chemical burn effect)
-> rumen atony & decreased absorption
-> erosions & ulcers
-> fluid enters rumen from osmotic pressure
-> secondary fluid bloat
-> metabolic acidosis (D-lactate absorption)
-> hypovolemic shock
-> secondary bacterial/fungal infection
-> septic emboli
-> liver abscesses
Rumen acidosis clinical signs
- dehydration
- abundant grain & fluid in rumen
- acidic smell of rumen contents
mucosal lesions (papillae blunting, erosions/ulcers, infarcts, perforation, peritonitis)
True/False
Bacterial emboli in ulcerative rumenitis can lead to vasculitis and infarcts, while fungal emboli can lead to liver abscesses.
False
bacterial emboli = liver abscess
fungal emboli = vasculitis, infarcts
True/False
Rumen acidosis can lead to laminitis
True
In dogs with aspiration pneumonia and history of chronic regurgitation, you should rule out an acquired stricture caused by all EXCEPT:
Cardiac Ventricular Septal Defect
In cows and other ruminants, Rumen Acidosis Syndrome is caused by _ A _ diets that result in rumen dysbiosis through a fermentation process that creates _ B _ volatile fatty acids with a _ C _ in rumen pH and _ D _ protozoa/gram negative bacteria with _ E _ acid-producing gram+ bacteria (lactobacillus, streptococcus).
A = Carbohydrate-rich
B = Excessive
C = Drop
D = Decreased
E = Increased
Rumen acidosis often produces secondary bloat (ie, rumen tympany) from ‘stasis’ as well as through an osmotic drawl of fluid into the lumen. Rumen acidosis can lead to rumen ulcers as well as lameness due to _.
Laminitis
