L1: Digestive System Path: Forestomach, Intestines (Castleman) Flashcards
3 main types of path of rumen/reticulum/omasum
- infectious inflammatory diseases
- chemical ruminitis
- bloat (tympany)
types of infectious rumenitis/omasitis/reticulitis
erosive/ulcerative proliferative necrotizing (seen with fungal and toxicity) psuedomembranous granulomatous
appearance of mycotic omasitis
bullseye lesions with coag necrotic center caused by depopulization of rumen mucosa and infiltration of fungal agents (is aspergillus) to invade and underline mucosa
pathogenesis of rumenitis caused by lactic acidosis
1) carbohydrate overload
2) lactic acid burn of mucosa
3) acidosis
4) scarring, mycotic infection or bacterial infection –> necrotizing hepatitis
appearance of rumenitis
cooked appearance, sloughing of epithelium due to low pH, scarring
types of path of stomach/abomasum
- ulcers
- inflammatory disease
- rupture
- neoplasia
associated conditions of ulcers
- trauma, chemical injury
- high acidity
- local ischemia
- helicobacter spp.
- parasites
- neoplastic disease: mast cells and gastrin-producing tumors
how do mast cells induce ulceration
stimulate H2 receptors to produce acid
2 things that cause ulcer of glandular mucosa of stomach
1) ulcer (various causes)
2) gastric carcinoma
risk factors of abomasal ulcers
(poorly defined)
- calving and early lactation in dairy cows (maybe due to stress, diet, perfusion)
- rapidly growing calves fed 2x daily
- calves, cows/bulls treated with NSAID’s
sequelae of abomasal ulcers
- fatal hemorrhage
- chronic hemorrhage
- perforation and peritonitis
appearance of chronic abomasal ulcers
- similar to chronic ulcers in monogastrics
- raised borders
where are pigs most likely to get stomach ulceration?***
SQUAMOUS portion of stomach, which is around cardia. NOT glandular mucosa as in other animals.
causes of gastritis/abomasitis
1) Infectious (clostridial, fungal, parasitic, helicobacter)
2) toxic
appearance of clostridial abomasitis
-necrotic, hemorrhage with GAS BUBBLES (induced by clostridial exotoxins)
appearance of Osteragiasis
- imbedded L3/L4 larvae –> thick, lumpy appearance
- results in Protein Losing Abomasopathy
gastric rupture assoc. with what in horse?
SI obstruction
how can you tell if gastric rupture occured antemortem?
if hemorrhage present along ruptured edge
types of gastric/abomasal neoplasia
- adenocarcinoma (tumor of mucus cells)
- leiomyoma/leimomyosarcoma/GIST (smooth m. tumor/spindle cell tumors)
- lymphoma (commonly ST in cats, abomasum in cattle)
- squamous cell carcinoma (horses)
T/F: leiomyomas often clinically silent
T
GIST =
gastrointestinal stromal tumor (a type of spindle cell tumor)
3 types of spindle cell tumors
leiomyoma
leiomyosarcoma
gastrointestinal stromal tumor
-usually clinically silent until invade and cause peritonitis
Q: most likely cause of diffuse hyperplastic abomasitis in bovine is:
a) ostertagia ostertagi
b) bovine virus diarrhea virus
c) aspergilus sp.
d) mycobacteria bovis
e) arcanobacter pyogenes
A) ostertagia ostertagi (see pic slide 64)
see slide 64/65 of L01***
:)
causes of GI obstruction
- gastric/abomasal volvulus
- intestinal volvulus/torsion
- intestinal external herniation
- intestinal internal herniation/entrapment
- intussusception
- intestinal stenosis/atresia
- intestinal stricture
- enteroliths and impactions
consequences of volvulus
- obstruction of lumen
- obstruction of vascular supply and hemorrhagic infarction
torsion def.
twist around the long axis of the intestinal segment
volvulus def.
twist in axis outside the long axis of the organ and involving the mesentery
strangulating lipoma common in older horses
T
intussuscipiens vs. intussusceptum***
intussuscipiens on outside, intussusceptum on inside
predisposing factors for intussusceptions
- enteritis/altered motility
- intestinal FB (esp. linear FB)
- intestinal polyp/neoplasm
linear FB induces ulcers on what border?**
MESENTERIC (can result in peritonitis)
4 types of stenosis/atresia
(se on pg. 79)
- stenosis (narrowing of lumen)
- membrane atresia (membrane goes across lumen)
- cord atresia (cord in place of continuous lumen)
- blind end atresia (completely separated segments)
is atresia developmental?
yes
is stenosis developmental?
no
chars. of intestinal adenocarcinoma in DOGS
age: 9yo
- more common in males
- colon/rectum (55%) or SI
- plaque like or ulcerated appearance +/- polypoid
- usually constrictive in SI
behavior of adenocarcinoma if untreated
spreads to local LN, peritoneum, liver
chars. of intestinal adenocarcinoma in CATS
- age: 11yo
- males more common
- Siamese cats
- 90% in SI
- almost always annular and constrictive/obstructive
2 types of epithelial tumors
adenoma
adenocarcinoma
sequelae of intestinal lymphangiectasia/lymphatic lipogranulomas
dilation of lymphatics –> PLE, can’t absorb fat well, lymphopenic
know what linear FB looks like grossly***
(pg. 84)
slide 85/86***
:)
what allows villi to contract?
smooth m.
where are stem cells in intestine?
crypts
3 mechs. of diarrhea in enterocolitis
1) maldigestion/malabsorption: Osmotic (due to villous atrophy, etc.)
2) Secretory mechanisms: Cl- secretion (from infectious agents working at lvl of crypts)
3) increased permeability (due to mucosal epithelial damage)
types of exudate in enterocolitis
- necrotizing
- fibrinonecrotic
- hemorrhagic
- proliferative
- granulomatous
what things cause villous atrophy?
virus, protozoa including: -coronavirus -rotavirus -cryptosporidia -enteric calicivirus -norovirus -enteric synctial virus -parvovirus -astrovirus - some E. coli "CREEP CANE"
what things target intestinal crypt cells?
- parvovirus
- BVD
- Rinderpest
- mycotoxins
- radiation
Q: Which of the following infectious agents induces necrosis of crpyt epithelial cells?*****
a) rotavirus
b) coronavirus
c) Cryptosporidia sp.
d) parvovirus
parvo (also, feline panleukopenia)
classic dz resulting in fibrinonecrotic lesions and fibrin casts**
enteric salmonellosis
pathogenetic mechanisms of salmonella
1) attach to M-cells, enterocytes, and goblet cells
2) survive in phagosome
3) enterotoxin/verotoxin/endotoxin induce necrosis of mucosa
4) upregulation of Cl- secretion via PGE2
3 forms of salmonella
1) Peracute septicemia
2) acute enteric salmonellosis
3) chronic enteric salmonellosis
peracute septicemia form of salmonella–>
vasculitis, thrombosis
acute enteric salmonellosis form of salmonella –>
enterocolitis, septicemia (hepatocellular necrosis, lymphadenomegally, splenomegaly, fibrinous cholecystitis)
chronic enteric salmonellosis –>
enterocolitis, thrombosis, rectal stricture in pig
what other bacteria can cause fibrinonecrosis besides salmonella?**
E. coli
Clostridium difficile
Lawsonia intracellularis
Causes of hemorrhagic enterocolitis (4)**
Clostridia perfringens
Shigellosis (primates)
Lawsonia intracellularis (pigs)
coccidiosis
2 causes of hyperplastic (proliferative?) enterocolitis**
Lawsonia intracellularis
Coccidiosis
2 causes of granulomatous enterocolitis**
1) mycobacterial infection (ie. Johne’s disease)
2) Histoplasmosis, deep mycoses
Q: which of the following infectious agents most commonly induces fibrinonecrotic enterocolitis?
a) Rotavirus
b) Salmonella
c) Cryptosporidia
d) Mycobacteria
e) Lawsonia intracellularis
B) Salmonella sp.
Q: which most commonly induces proliferative enteritis?
a) rotavirus
b) salmonella
c) cryptosporidia
d) mycobacteria
e) Lawsonia intracellularis
e) lawsonia intracellularis
