Alimentary System Flashcards
What is Brachygnathia superior/inferior?
Short maxilla/mandible
What is prognathia?
Long maxilla/mandible
What is cleft palate/palatoschosos?
- Inadequate growth of palatine shelves
- Midline defect of hard and/or soft palate
- Causes aspiration pneumonia and problems with sucking
What is Hare lip/cheiloschisis?
Absence of part of lip rostral to nasal septum
What is stomatitis?
Inflammation of the oral cavity
What is the most common oral malignancy in cats? Describe its features.
- Squamous cell carcinomas of the oral cavity
- Malignant epithelial tumour
- Often on the ventrolateral tongue
- Locally invasive with/without metastases
- Composed of elevated firm, white plaques or nodules that may ulcerate
- Irregular masses and cords of squamous epithelium invading the lamina propria
- Forms circular “pearls” of keratin
What is the most common oral malignancy in dogs? Describe its features.
- Tumours of pigment-producing melanocytes
- Nearly always malignant in the oral cavity
- Grow rapidly
- Oval or spindle-shaped melanocytes with variable melanin content
What are Epulis periodontal tumours?
- Group of benign neoplasms of periodontal origin affecting gingivae, particularly in brachycephalic breeds
- Firm lesions on gums surrounding teeth, especially carnassia/canine region
- Dense collagenous and sometimes ossified tissue covered with stratified squamous epithelium which descends into stroma in cords
What is oesophageal achalasia?
Failure of cardiac sphincter to open.
How may megaoesophagus be aquired?
- Neurological
- From equine grass sickness, for example
- Muscular
- From myodegeneration
What is ruminal tympany? Describe the different types of this disorder.
- Ruminal bloat: rumen becomes distended with gas or fermenting feed
- Primary
- Frothy bloat- formation of stable foam in rumen from ingestion of high protein lucerne/clover or high concentrate/low roughage dies
- Secondary
- Mechanical/functional obstruction of oesophagus leading to accumulation of gas
Describe traumatic reticulitis.
- Ingested sharp objects will fall to the floor of the reticulum and be forced into the body wall via contractions
- Causes mild suppurative or granulomatous reticulitis with/without mild peritonitis
- Foreign body penetrates cranial wall, encouraged by rumen contractions
- Results in acute peritonitis which progresses though the diaphragm and forms local fibrous adhesions
- Can cause fibropurulent pleuricy, pneumonia, and pericarditis
- Inflammatory processes around reticulum may also lead to “vagus indigestion” and ruminal stasis
What is a cause of papillomatosis in the bovine rumen?
Bovine papillomavirus type 4
What is a cause of squamous cell carcinoma of the rumen?
Develops from papillomas in cattle in association with ingested carcinogens in bracken fern
What is the most common presentation of abomasal displacement?
Left displacement
What is evidence that a gastric rupture occured antemortem rather than as an agonal change when observed at post-mortem?
Evidence of haemorrhage and peritonitis
What is the most common gastric neoplasm in small animals? What is a characteristic of this neoplasm?
- Adenocarcinoma
- Locally aggressive and spreads via lymphatic vessels
What is the most common gastric neoplasm of horses?
Squamous cell carcinoma
What is the target of gastrointestinal stomal tumours?
Interstitial cells of Cajal
What is exudative diarrhoea? Describe this conditon.
- Caused by loss of the integrity of the mucosa causing exudate
- Inflammatory products present
- increased vascular permeability
- Erosion and ulceration present
- Increased mucosal permeability with interstitial fluid moving into the lumen with increased hydrostatic pressure
- Can be accompanied by decreased oncotic pressure with hypoalbuminaemia and protein lost in exudate
What is lymphangiectasia?
- Loss of protein-rich lymph due to obstruction of intestinal lymphatic vessels
- Causes severe protein loss
- Often due to neoplasia
- May be an idiopathic condition
- Lacteals become dilated
What are the most common causes of intestinal hypoxia/necrosis?
Strangulating lesions/intussusception
What is typhlitis?
Inflammation of the caecum
What is proctitis?
Inflammation of the rectum
Describe the sequelae of infection for parvoviral enteritis.
- Initial multiplication of virus in lymphoid tissues
- Viraemia
- Villous atrophy results from inability to replace enterocyte from crypts
- Necrosis of crypt epithelial cells leads to crypt dilation
What is the lamina propria mucosae? Why is is susceptible to infection?
- Thin layer of loose connective tissue, or dense irregular connective tissue, which lies beneath the epithelium and together with the epithelium constitutes the mucosa
- Has a poor inflammatory response, making it susceptible to infection
What causes Feline Infectious Peritonitis? How can this manifest?
- Caused by Feline coronavirus
- Forms
- “Wet” (effusive) form with white miliary granulomas and fibrin on serosa plus high protein exudate in peritoneal cavity
- “Dry” (non-effusive) formCharacteristics
- White-gray granulomatous masses in wall of intestine
- mutifocal pyogranulomas on serosa and in wall
- infiltration by lymphocytes, plasma cells, macrophages, and neurophils
- necrotizing vasculitis also present
What is being pictured here? What causes this?
- Hepatocyte Vacuolation
- Fatty change
- Lipid accumulates in cytoplasm of injured hepatocytes and hepatocytes are unable to function normally
- Reversible but may progress to lipidosis (steatosis)
- Grossly, liver is pale yellow, friable, and greasy
- Hepatocytes distend by discrete circular lipid vacuoles which displace the nucleus to the periphery of the cell
- Massive uptake of fatty acids from blood following excessive mobilization of peripheral adipose tissue reserves
- Overloads metabolic capacity of hepatocytes and further inhibits their function
- Vacuolation of hepatocytes: large clear vacuoles which push the nucleus to one side. In each cell there is a single large, clear empty vacuole, lipid present which has been dissolved out
What is steroid-induced hepatopathy?
Excessive glycogen accumulation in the hepatoctyes in the presence of high levels of corticosteroids (endogenous or exogenous (iatrogenic))
Describe hepatic amyloidosis.
- Types
- Primary: Familial (genetic)
- Secondary: Usually follow chronic inflammation
- Grossly: Liver becomes enlarged, pale and firm but friable, with rounded borders
- Histologically
- Amyloid protein is deposited extracellularly along sinusoids in space of Disse and around portal areas
- Green birefringence can be seen under polarizing light when stained with congo red
Describe cirrhosis.
- Diffuse, irreversible, end-stage hepatic disease
- Destroys function
- Mostly seen in dogs
- Cause cannot always be established
- Affected animals exhibit hepatic insufficiency (hypoproteinaemia, ascites) or liver failure when severe, including icterus/jaundice (hyperbilirubinaemia), hypoproteinaemia (ascities, coagulopathy), ammonia retention (hepatic encephalopathy), secondary photosensitisation (herbivores, phylloerythrin (product as a result of consuming chlorophyl-filled plant material) not excreted due to cholestasis)
- Grossly: Liver is small, misshapen, fibrosed, irregular
- Histologically: loss of hepatocytes, collapsed parenchyma, nodular regeration, lack of central veins
- Briding fibrosis (can be surrounding regenerative nodule)
- Bile ductules will be proliferative
- There is bridging fibrosis, biliary hyperplasia, nodular regeneration, and hepatocyte destruction
Describe hepatic telangiectasis.
- Dilation of groups of sinusoids filled with blood
- Incidental finding in cattle and cats
- Grossly: Red and purple areas
- Cause is idiopathic
How does congestive heart failure manifest ine th liver?
- Causes the liver to have chronic venous congestion
- Back flow of blood through the vena cava causes congestions in the liver
- Fibrin strands in the peritoneal cavity
- Can cause liver to have “nutmeg” appearance
Describe ragwort (Senecia spp.) toxicity in the liver?
- Pyrroliziding alkaloids are activated in the liver which Inhibit cellular division
- Megalocytosis of hepatocytes are apparent histologically
