Lecture 12: GI 3 (lower GI) Flashcards
How do the number of taniae change throughout the equine cecum/colon?
Cecum: 4
R ventral: 4
Sternal flexure: 4
L ventral: 4
Pelvic flexure: 1
L dorsal: 1
Diaphragmatic flexure: 2
R dorsal: 2
What is a common insignificant lesion in the equine intestine?
hemomelasma ilei which are dark and elevated hemorrhagic plaques in the ileum. This is due to strongyle migration
What is a common insignificant lesion in the pig intestine?
intestinal emphysema also known as pneumotosis cystoides intestinalis
What are 2 segmental congenital abnormalities of the intestinal tract and what is a common consequence?*
Stenosis, or the narrowing of a lumen or atresia which is the complete occlusion of the intestinal tract. This leads to ischemia and failure to pass feces at birth
A Holstein calf presents for necropsy with abnormal dilation and constriction of the spiral colon. What is a likely differential?*
Atresia coli is an autosomal recessive condition in which the colon does not develop. This is most common in Holstein calves in their spiral colon. it will appear as oral dilation (dilation before the obstruction) and aboral constriction. Often there will be an enlarged uterus that is backed up with feces.
This condition can also affect foals in their small and large colon
What species are associated with atresia ani?*
It is a hereditary condition affecting calves and pigs primarily
What is the most common GIT congenital defect?
atresia ani
What can cause atresia ani? What additional problems may occur?*
Vitamin A deficiency may cause it.
Animals with this condition may also have malformations in the distal spinal column, genitourinary tract, or intestinal atresia or agenesis
What are the 4 types of acquired intestinal abnormalities
They can be
-luminal
-mural
-external
-functional (due to neuro)
How do you compare acute and chronic intestinal obstruction?
Acute obstructions typically affect the upper or mid small intestine. It can result in vomiting, dehydration, hypochloremia, hypokalemia, and metabolic acidosis.
Chronic obstruction affects the ileum or large intestine. It does not involve vomiting or metabolic acidosis. It can cause necrosis, perforation, and peritonitis
A cat presents for necropsy and upon examination you see a pleated intestine, what is your top differential?*
Linear foreign body.
Peristalsis of the linear foreign body like a string will cause pleating of the intestine and mucosal damage
What are 6 types of intestinal luminal obstructions*
foreign body
trichobezoar
phytobezoar
enterolith
parasite
colonic impaction
What is an enterolith and why does it occur?
It is a mineralization of magnesium, ammonium, and phosphate. It can be caused due to diet, alkaline water, colonic pH, or a nidus.
A horse from Florida or California presents for necropsy and you find a mineralized intestinal rock-like thingy. What is it? Is it significant?
An enterolith (mineralization of magnesium, ammonium, and phosphate)
Usually and insignificant lesion
What is a common GI parasite that causes luminal intestinal obstruction?
Small colon nematodes
What is a common cause of colonic impaction in small animals? What is a secondary consequence of this?
obstipation (feces) which can cause megacolon
What is a common cause of colonic impaction in horses? What can cause it?*
It is usually caused by digesta, sand, or feces in the pelvic flexure or transverse colon
It is often secondary to reduced water intake, diet change, or poor dentition
What are 2 types of mural intestinal obstruction?*
jejunal hematoma
rectal stricture
What is another name for jejunal hematoma?*
hemorrhagic bowl syndrome (old name)
A dairy cow from North America that was in mid-lactation presents for necropsy after sudden death, she was anemic with pale MM and had segmental intramural and luminal hemorrhage, what is your top differential and why?*
Jejunal hematoma which is most common in dairy cows usually in mid-lactation. It presents with segmental intramural hemorrhage and potentially with luminal hemorrhage as well but not always (it can rupture from the wall into the lumen)
Clinically these cows present with hemorrhage and bloody feces, bloat, abdominal pain, and sudden death. Due to the hemorrhage there is anemia and pale MM
What is a common cause of jejunal hematoma?
The cause is unknown, there may a potential it is related to aflatoxin
What is a common cause of reduced fecal output and significant abdominal distension in pigs?*
Rectal stricture
What causes rectal strictures?*
It is secondary to Salmonella typhimurium infection in the intestines of pigs. It will cause necrotizing proctitis and ischemia resulting in scarring and contraction. It is most common at the junction of the caudal mesenteric and pudendal artery because there is no collateral flow
What are 3 common causes of extramural obstruction? Which is the most common?*
strangulating lipoma (most common in horses)
neoplasia
peritoneal adhesion
What is the pathogenesis of intestinal displacement? *
- The intestine is displaced into an abnormal position
- It will become incarcerated aka. stuck in a bad position
- It will become strangulated due to reduced blood flow resulting in edema, congestion, and hemorrhage
This results ischemia and ultimately necrosis
Define volvulus*
When the organ twists on the mesenteric axis
Define torsion*
When the organ twists on its long axis
What species/type of animal is predisposed to intussusception?*
It usually targets young dogs in their ileocolic area
What is an intussusception?
a telescoping intestine
How do you name an intussusception?*
The intussuscipiens recieves the intussusception
Describe what an ileocolic intussusception means?*
the ileum is the intussusceptum and it moves into the colon the intussuscipiens
What causes intussusceptions?
They can be idiopathic but also due to
- linear foreign bodies
- a high parasite load
- previous surgery
- enteritis
- intramural mass
or it can be a perimortem change
A horse presents for a necropsy with an intestinal intussusception and a parasite load. What is the most likely parasite that you found?
High parasite loads of Anaplocephala perfoliata can cause intussusception in horses
What organs are usually entrapped in an abdominal hernia
Usually omentum and intestines. Other organs are rare to find