Path 2 - Alimentary 3

drraythe's version from 2016-03-16 00:20


Question Answer
What is happening in cricopharyngeal achalasia? Who does this affect most commonly? (sp?) cz? How does it present?This is when the upper esophageal sphincter doesnt relax during swallowing, so food cant get through. It is Rare, but happens most often in miniature poodles, cocker spaniels. The cz is usually not known (idiopathic). Suspect is usually congenital. Sometimes you will see lesions in the cricopharyngeal mm (Fibrosis, muscular hypertrophy, muscular atrophy, myositis) but other times no lesions will be seen
What is megaesophagus? What does it look like? CS? What are the 2 categories of megaesophagus?Absence/ ↓ fxn of muscles of the upper & middle portions of the esophagus. Esophagus flaccid, sacculated. Affected animals often vomit undigested food up to 30 minutes after eating. Megae. Can be congenital or acquired!
What are the 2 examples of CONGENITAL megaesophagus?Idiopathic & persistent right aortic arch
How common is Idiopathic congenital megaesophagus? WHO does this occur in most often? What are some possible reasons for this?Happens in DOGS (great Danes, German shepherds, Irish setters, miniature schnauzers, wirehaired terriers, Newfoundlands, shar peis), CATS (Siamese) & foals. It is probably a Neuromuscular development disorder or immaturity of neuromuscular control. Some dogs out grow the problem.
What is happening in persistent right aortic arch? WHO (sp) is this most common in?Right 4th aortic arch develops instead of the left 4th aortic arch. It isnt common, but it happens most often in Irish setters, German shepherds & Boston terriers (the german-irish in Boston have their heart in the right place, but not their aorta)
What are 4 situations where there is ATQUIRED megaesophagus(1) 2° to damage
(2) Myasthenia gravis (autoantibodies to acetylcholine receptors, controlling mm of eso)
(3) Hypothyroidism ( czs muscle atrophy)
(4) Nerve damage (from certain toxins, like lead & thallium)
What are the 2 main types of esophageal obstructions?Intraluminal & periesophageal obstructions
intraluminal esophageal obstructions are usually due to foreign bodies. Explain some nuances of this when it comes to ruminantsIn rumis, you have "choke" (eso obstruction) which can lead to "bloat" (inhibition of eructation, so gas builds up in the rumen & the cow starts to bloat up). If the bloat was the cz of death, you could differentiate it from post-mortem bloating by the presence of a bloat line
BLOAT LINE → explain it. Why does it look like that.Due to ruminal bloat from an eso. obstruction. the line is at the thoracic inlet (where the object usually gets stuck) & the white side is on the abdominal side, where all the blood is pushed from the tissue due to ↑ intraabdominal pressure. The red side is on the thoracic/throat side, bc blood is not pushed out, but is backed up from not being able to pass the obstruction
What are the 3 main czs of periesophageal obstructions(1) Persistent right aortic arch
(2) Inflammation
(3) Neoplasia
What is the main czs of esophageal rupture?Usually a sharp foreign body, or iatrogenic (forcing a tube VERY HARD down their throat)
What is the main cz of an esophageal diverticulum? What can happen?Usually congenital, but can be czd by a partial tear which then out-pouches. Food/matter can accumulate in this diverticulum & this can lead to rotting/irritation/sloughing/etc
Esophageal hypertrophy usually happens in who, where? Results?Usually happens in horses in the last 6in of esophagus before the cardiac sphincter. Usually this presents as no problem, but might play a role in chronic esophageal impaction
What are the 2 main czs of Esophagitis?Gastric reflux & viral
What is happening in esophagitis czd by gastric reflux?Damage to esophageal mucosa by digestive acids & enzymes from the stomach
What are some viruses which can cz esophagitis?Erosive/ulcerative esophagitis czd by viral agents (MCF, BVD, IBR, feline calicivirus)
Name 3 parasites which infect the esophagusGongylonema
Spirocerca lupi
Hypoderma lineatum
What should we know about Gongylonema? Who does it affect?Looks like little wavy/serpentine patterns just below the superficial mucosa of the esophagus. Usually these do not present any problems. Most often seen in cattle (IH is dung beetle or cockroach)
What should we know about spirocerca lupi?Burrows into mucosa of distal esophagus & czs GRANULOMAS to form, which they live inside of. Granulomas may cz blockages. (In dogs, fibrosarcomas & osteosarcomas might happen as a result of the S. lupi granulomas) (IH dung beetles)
What should we know about Hypoderma lineatum?(Aka cattle bot fly) the bot fly will pass through the eso. On its migration to the skin of the back of the cattle. If the larvae dies in the esophagus, there can be a severe inflammatory rxn which can occlude the eso & cz bloat → death
Which fungus usually czs mycotic esophagitis?Candida albicans (yeast)
What are the 3 types of neoplasias most commonly associated w/ the esophagus?(1) Papillomas
(2) SCC
(3) S. lupi associated, ie, fibromas, fibrosarcomas, osteosarcomas
Which neoplasias can result from a S. lupi infxn?Fibromas
Esophageal achalasia vs cricopharyngeal achalasiaEsophageal = Lower sphincter
Cricopharyngeal = Upper sphincter (wont loosen)
In persistent right aortic arch, what is forming the "ring" around the esophagus?Aorta
Pulmonary artery
Ductus arteriosus (Ligamentum Arteriosum)


Question Answer
Since stomach is always at risk of being damaged by acid & enzymes, it needs protective mechanisms. name 4(1) Intact layer of epithelial & mucus cells-intracellular tight junctions
(2) Layer of mucus
(3) Bicarbonate ions secreted by epithelial cells into mucus layer
(4) Prostaglandins (inhibit acid secretion, stimulate bicarbonate secretion, vasodilation & ↑ blood flow)
(ALSO: Mucosal immune system, Mucosal microcirculation allows for clearance of back-diffused acids, acid exits as "jets" to leave an undisturbed mucus layer)
How are prostaglandins protective to the stomach?Inhibit acid secretion
Stimulate bicarbonate secretion
↑ blood flow
What are the 2 1° mechanisms of gastric ulcers?(1) Hypersecretion of acid
(2) Injury to protective layer
What are 2 possible czs of hypersecretion of acid which might lead to gastric ulcers?(1) Gastrinomas (tumors of islet cells that produce gastrin)
(2) Mast cell tumors (↑ histamine production leading to ↑ acid production) (lots of acid from lots of cells, ie, neoplasia)
What are 4 ways that the protective layer can be damaged, which can lead to an ulcer?Direct damage
Infectious agents & drugs
What are 2 drugs which can cz ulcers & how?(1) Corticosteroids (czs ↓ epithelial repair, ↓ prostaglandin (inhibit acid secretion, stimulate bicarbonate secretion, vasodilation & ↑ blood flow)
(2) NSAIDs (ex: aspirin, Bute, indomethacin....can be directly toxic (organic acids), cz ↓ prostaglandin synth, bc inhibit cyclooxygenase, which is important in conversion of arachidonic acids to prostaglandins)
Which swine are prone to gastric ulcers & what risk factors (4) contribute to the ulcer?Feeder pigs
Corn (rather than wheat/oats)
Finely ground feed (as opposed to course)
Dry feed (instead of moist)
Unsaturated fats (rather than saturated)
Are all risk factors which contribute to the formation of gastric ulcers
What is the pathogensis/clinical appearance of gastric ulcers in feeder swine?Begin as hyperkeratosis/parakeratosis (thickening of squamous epi of lining), then intraepithelial necrosis. Erosions/ulcers usually form around cardia (pars esophagus) & their severity can range from subclinical to exsanguination(BLEEDING OUT) into gastric lumen
What are the 3 ways horses get ulcers?Idiopathic ulcers in foals
Equine Gastric Ulcer Syndrome
CS of idiopathic ulcers in foals?Abdominal pain
Excessive salivation
Grinding of teeth
Explain how NSAIDs can cz ulcers in horses & what are all the negative results of it?Happens through prostaglandin inhibition (remember that prostas: inhibit acid secretion, stimulate bicarbonate & mucus secretion, cz vasodilation & ↑ blood flow to mucosa.) Gastric ulcers, renal papillary necrosis & right dorsal colitis
Equine gastric ulcer syndrome – who does this affect & how common is it? Cz?Happens in performance horses, from 40%-90% of the time & the cz is unknown (possibly stress)
How do ferrets get ulcers? Explain what is going onThese are czd by Helicobacter mustelae & the pathophysiology in ferrets is suspected to be similar to that of humans
Acute gastric dilation & volvulus → which dogs does this affect most? When does it usually happen?Deep chested dogs following a large meal & aerophagia (or perhaps gas produced by Clostridial species. Either way, gas in the belly)
What is is the pathophysiology of the "dilation" of acute gastric dilation & volvulus?After a large meal, the food swells & the stomach expands. Then, long axis of stomach assumes longitudinal orientation in the abdomen instead of its usual transverse position against the liver & diaphragm. Wall congested
What is is the pathophysiology of the "volvulus" of acute gastric dilation & volvulus? What are some of the results?170 to 360 degree clockwise Rotation of the stomach (as viewed from ventral surface). Duodenum & esophagus become twisted around each other. The spleen goes (at least part of the way) w/ the stomach. Folds upon itself. Bc of this, there is severe congestion & infarction in the stomach & spleen. → Acid-base & electrolyte abnormalities, cardiac arrhythmias (myocardial depressant factor) → Gastric rupture, shock & death, peritonitis
Explain 1° vs 2° acute dilation of the equine stomach. What do both usually lead to?1⁰: Overeating, lush pastures, excess water intake (directly cz the dilation)
2⁰: Gastric ulcers, neoplasia, pyloric stenosis, “cribber” horses. Both can lead to gastric rupture
What is "garbage gut"? Describe the mucosa of the stomach in this conditionUsually used to describe dogs w/ gastritis, bc they will eat old garbage which is rotting & contains toxins which will damage the mucosa. (Long notes said aka Acute hemorrhagic gastritis). The mucosa will be hemorrhagic & full of edema
What are 3 parasites in the horse which can cz gastritis? Explain a little about them(long notes expanded on these quite a bit)(1) Gastrophilus (aka bot flies)
(2) Drachia
(3) T. axei
(The HORSE DRAChula would AX the horses GASTRIC)
(Note - "Habronema" in long notes. another parasite which czs gastritis)
Gastrophilus - in who? Whats it about & whats going on?HORSE - (Aka bot flies) Larvae get licked, embed in oral mucosa, migrate out & get swallowed, In the stomach they attach to the squamous portion of the stomach (intestinalis) & glandular stomach/duodenum (nasalis). (3 parasites of horse - The HORSE DRAChula would AX the horses GASTRIC)
Drachia - in who? Whats going on?Horse - Most severe gastritis from this (dracula is pretty fucking severe). in a nodule (brood pouch) in the glandular portion of the stomach adjacent to the Margo plicatus.(3 parasites of horse - The HORSE DRAChula would AX the horses GASTRIC)
T. axei - in who? What’s going on?Horse - burrow into the gastric glands in the mucosal portion of the equine stomach. They cz raised whitish thickened areas in the mucosal portion of the horse stomach, aka, bumpy lumpy mucosa (3 parasites of horse - The HORSE DRAChula would AX the horses GASTRIC)
What are 3 parasites in cats/dogs which can cz gastritis? Explain a little about them(1) Ollulanus (found on the gastric mucosa. May cz mild to moderate gastritis)
(2) Gnathostoma (found in nodules in the gastric mucosa. They are rarely a problem. Spirally looking)
(3) Physaloptera (can be found in the stomach & are occasionally expelled in vomitus. They are usually attached to proximal duodenal mucosa. Intermediate hosts are dung beetles. Decent sized worms)
(GNAT (who is harmless) has OLLU! to the PHYne cats & dogs)
Ollulanus - in who? What’s going on?Dog/cat. Found on the gastric mucosa. May cz mild to moderate gastritis (for all cat/dog parasites-GNAT (who is harmless) has OLLU! to the PHYne cats & dogs)
Gnathostoma - in who? Whats going on?Cats/dogs. Found in nodules in the gastric mucosa. They are rarely a problem. Spirally looking (gnat was a sweet harmless girl who just twirled her hair & smiled) (for all cat/dog parasites-GNAT (who is harmless) has OLLU! to the PHYne cats & dogs)
Physaloptera - in who? Whats going on?Cats/dogs. Can be found in the stomach & are occasionally expelled in vomitus. They are usually attached to proximal duodenal mucosa. Intermediate hosts are dung beetles. decent sized worms (for all cat/dog parasites-GNAT (who is harmless) has OLLU! to the PHYne cats & dogs)
What czs fungal gastritis? Explain who's affected (broad & specific), where, prognosis?Pythium insidiosum - an oomycete, not a true fungus, that can cz chronic pyogranulomatous gastritis & gastroenteritis in dogs (also a cutaneous form in horses! usually lower legs). Tend to effect lg breeds of dog that like water. Bad stuff – no good Tx. If infxn is not extensive the infected portion of the stomach can be surgically excised.
Whats up w/ Pythium insidiosum?An oomycete which can cz fungal gastritis in dogs & a cutaneous infxn on the lower limbs in horses. (Python biting a dogs stomach & the legs/skin of horses will leave nasty red sores)
What are the 3 main neoplasias which can cz gastritis? Who is most affected by which?Adenocarcinoma (mostly dogs, arise from epi. cells)
Lymphosarcoma (most often in cats-cats always are sarcomas)
SCC (mostly horses/llama-theyre out in the sun the most)
(also gastric mast cell tumor mostly in dogs & leiomyoma & leiomyosarcoma, sm mm, not very common)
Explain the connection btwn uremia & gastritis.Urea damages small vessels in wall of stomach & in lumen, bact can convert urea into ammonia & that will cz more damage

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