Lecture 7: Abnormal Conditions of Equine Small intestine Flashcards
What are the two classifications of obstructions
- Simple/ nonstrangulating vs strangulating
- Functional vs mechanical
What is a simple/ nonstrangulating obstruction
Blood supply to intestine involved in the obstruction remains patent
How does peritoneal fluid in a simple/ nonstrangulating obstruction look
Grossly normal
What is a strangulating obstruction
Blood supply is constricted/blocked which results in mucosal ischemia injury and endotoxemia
What is a functional obstruction
Lumen of the intestine involved remains patent but motility is altered
No blockage
What is a mechanical obstruction
Lumen is blocked
How does peritoneal fluid look in a strangulating obstruction
Serosanguineous
What are some causes of non-strangulating/ simple obstructions
Ideal impaction, ascarid impaction, enteritis
How does the ileum appear in an ileum impaction
Mostly normal but enlarged- doughy to solid tubular mass that extends ileocecal junction
What can cause ileal impactions
High prevalence related to feeding costal Bermuda grass hay
Regional: southeast US
Risk for ileal impactions increases by recent introduction to __ or feeding ____
Bermuda hay or poor quality hay
What is the pain for ileal impactions attributed to
Spasmodic bowel contraction around impaction- more severe and constant pain as small intestinal distention progresses
What would rectal exam reveal in an ileal impaction
Small intestine distention in right dorsal quadrant behind cecum
What are some rule outs for ileal impactions
Strangulating obstruction, enteritis
What is the treatment for ileal impactions
IV fluids, banamine, mineral oil via NG tube
What is the prognosis for ileal impactions
Favorable if treated early
If delayed: gastric rupture, mucosal necrosis, ileal perforation
What is the main ascarid that affects horses
Parascaris equorum
What age are ascarid impactions common
Foals and young horses
What do ascarid have widespread resistance to
Ivermectins
What is tx for ascarid impaction
Surgery
What is post-operative mortality for ascarid impactions and why
92%- focal necrotizing enteritis, peritonitis, abscess formation, adhesions
Why do you not want to deworm a foal less than 60 days for ascarids
- Want them to develop immunity ~1yr
- Don’t want all worms to die then cause blockage
What are the best drugs to tx ascarid impaction
Oxibendazole> fenbendazole > pyrantel pamoate
What is DPJ
Inflammation of the proximal portion of the small intestine leads to endotoxemia and ileus and thus fluid accumulation in SI and stomach
What type of obstruction is DPJ
Functional
How do you diagnose DPJ
- Large NG reflux
- Severe pain initially then depression
- Tachycardia, pre renal azotemia, dehydration, hypotension, electrolyte abnormalities
- After NG reflux should have pain relief