Equine Med- Obstruction vs Strangulation of SI

wilsbach's version from 2016-02-19 04:50


Question Answer
Obstruction vs Strangulation why is it important?(1) Great impact on treatment plan (Strangulating lesions always require surgery). (2) Great impact on prognosis (3) Great impact on the owner’s wallet!!!!!
describe the diff between obstruction and strangulation in terms of.. what kinda obstruction are these? what parts of the GI are compromised?BOTH are mechanical obstructions. However..... a SI obstruction is a simple obstruction where only the lumen of the bowel is blocked, so flow of ingesta is impeded, but blood supply is intact so it is non-strangulating. A STRANGULATION is a strangulating lesion, meaning both the lumen and blood supply are impeded leading to devitalized bowel
what are signs you'd see which would indicate there is devitalized bowel?Endotoxemia, Hemoconcentration, dehydration
if there is a obstruction in the SI, which way does the bowel dilate?orad dilation
Obstruction vs strangulation: level of pain?O: mild to mod. S: mild to SEVERE
Obstruction vs strangulation: response to analgesia?O: Good response to analgesia and/or gastric decompression. S: Brief response to analgesia (give meds and 10 min later colicking again)
Obstruction vs strangulation: whats the CV system doing?O: Minimal CV compromise. S: CV deterioration (Endotoxemia, Hemoconcentration, Dehydration)
Obstruction vs strangulation: whats peritoneal fluid like?O: WNL. S: Peritoneal fluid abnormal
Obstruction vs strangulation: which might have gastric reflux?O
what are the 2 main reasons horses will have a SI obstruction?Ascarid impaction (6mo-1yr old), Ileal impaction
what are the 4 main reasons horses will have a SI strangulation?Intussusception, SI volvolus, Pedunculated lipoma, Abdominal incarceration
what are the 3 main places there will be an abdominal incarceration causing a strangulating lesion?Epiploic foramen, Mesenteric rent, Inguinal ring hernia

Non strangulating lesions

Question Answer
WHAT IS THE ASCARID WHICH CAUSES THESE IMPACTIONS?Parascaris equorum, equine roundworm
what age is most prone to getting parascaris equorum impactions?Older foal and weanling disease-- usually see from 6mo-1yr... Immunity developed by 18-24 months so dont see in older horses
what is the hx usually like for a horse with an ascarid impaction?Poor deworming history / poor dooers, or Heavy worm burden and fast kill dewormer used
(said in class) how do you know if the worms in the horse are resistant to the dewormer you are using?do fecal egg count before deworming, then deworm, then do another FEC, and needs to be reduced 90%. if not that much, there is resistance to that dewormer. then you can advice owner to give an alternative.
ddx to ascarid impaction?lawsonia intracellularis-- ADR horse basically
So you do an US and you find a whole ton of worms in the GI of this 10mo old horse. And the owner is like "OMG KILL THEM ALL" and you gotta be like..."naw man, if you kill them all at once they will all move down the GI at once and cause an impaction. And when they die they get stiff and can puncture stuff. we need a low key dewormer."
what is the preparent period?prepatent period- 8-12 weeks from infection to first evidence that there is parascaris in that animal. that is the prepatent period.
***what is the infective stage of parascarias equorum?IT IS L2******* NOT L3!!!!!
what is the lifecycle of parascaris equorum?
clinical signs of an ascarid impaction?Unthrifty foal with colic and depression, HR↑, RR↑, and sometimes febrile, Signs of endotoxemia
how do you dx an ascarid impaction? History / signalment, Fecal egg count, Gastric reflux (with worms!!!!), Ultrasound abdomen
what is really weird about reflux in ascarid impaction?CAN HAVE REFLUX WITH WORMS IN IT!!
whats an ascarid egg look like?LIKE A ROUNDWORM bc it is a roundworm bruh
what is initial tx for ascarid impaction? what next?Gastric decompression / lavage initially. Then Anti-inflammatory therapy (Dead worms cause damage to SI wall). SX OFTEN INDICATED (--> poor prog bc young foals more predisposed to adhesion formation. so initially go home, but then come back within 2 months with recurrent colic, and there are adhesions everywhere in the abdomen )
what is a good dewormer for parascaris equorum? which one has reported resistance to it?Reported resistence to ivermectin. Benzimidazoles= appropriate choice fenbendazole (said in class moxidectin os C/I in horses <4mo)
If large worm burden is suspected, how should you choose your dewormer?use a less effective anthelcide- Reduce mass killing possibly reducing risk of obstruction
when and where in the world/season is ileal impaction most common?Most common in Southern US Jun-Nov (south in summer-fall)
what is Ileal impaction most often associated with (major risk factor)?Coastal Bermuda Grass
CS of ileal impaction?COLIC! Spasm of ileum around impaction---> Distention of proximal intestine (both are painful)
if you NG tube a ileal impaction, will you get reflux?yep
how can you dx a ileal impaction?Rectal exam: impaction may be palpated, distention small intestines
how is medical tx of ileal impaction different in early dz from late dz?EARLY DZ: Intravenous fluids, anti inflammatories, (maybe oral laxatives?). LATE DZ: Gastric decompression
when would you do sx tx of ileal impaction, and what do you do sx-ically?sx in CHRONIC cases. Manual massage to break down impaction. Enterotomy rarely needed
most common complication of sx tx of ileal impaction?Post-operative ileus (distention / inflammation) (basically hard from them to bounce back from sx and sm int can get pissed off)
how can you prevent ileal impaction?Avoid Coastal Bermuda Grass and Course fibrous feeds (also Deworm for tape worms??? <---praziquantel)
what is happening in ileal hypertrophy? (which part is hypertrophic)Muscular hypertrophy of the ileal wall
what is the presentation of ileal hypertrophy?Chronic colic (low grade pain for years), Inappetance, Weight loss
tx for ileal hypertrophy?Ileo or jejunocecostomy
Differential Dx SI obstructions (4)Neoplasia, Inflammatory Bowl Disease, Intra-abdominal Disease (Bastard strangles aka Metastatic strangles- strep equi equi), Adhesions (Scar tissue from previous colic surgeries)

Strangulating lesions

Question Answer
what is Intussusception? what are the diff types?Piece of intestine telescopes on itself- can be Jejuno-jejunal, Jejuno-ileal, Ileacecal, (Ceco-colic)
intuss. usually happen to what age of horse?young (Foals & weanlings) bc nutrition changes--> changes in motility
which two types of intuss. are associated with parasitism? which parasites for which intuss?(1) Tapeworm & ileocecal intussusception (Anoplocephala perfoliata) (2) Ascarid & jejuno-jejunal intussusceptions (Parascaris equorum)
intuss often associated with sudden...changes in diet
clinical signs of intuss?acute colic
tx for intuss?Surgery!
what is intuss like on rectal exam?dilated small intestines (in class she said cant palpate with rectal palpation bc cant really reach sm int,or the horses are young so too small )
what is intuss like with NG intubation?reflux +/-
what is intuss like on US?bulls eye is classic US image- pathognomonic
is peritoneal fluid normal or abnormal with intuss?abnormal bc inflammation
Small Intestinal Volvulus--> how much rotation for this to be considered volvulus?Loop of intestine twists upon itself > 180
**what is the most common sx colic in FOALS?Small Intestinal Volvulus
tx for SI volvulus?sx tx-- resection
how does volvulus happen? (pic)dorsal attachment of mesentery and then small intestines just all hanging and everywhere, so volvulus can occur.
when doing sx for volvulus, you need to consider what about the CV system?are just the arteries compromised, or just the veins, or both?
what is a Pedunculated lipoma?Benign fatty tumor in mesentery which has a mesenteric pendulous stalk
what age/ what breed is predisposed to pedunculated lipomas?Disease of older horses and esp. Arabians
CS of a pedunculated lipoma?acute colic
tx of pedunculated lipoma?surgery (Survival: 48-78%)
3 major complications after sx to fix pedunculated lipoma?Post operative ileus, Adhesions, Sequela of endotoxemia
Small Intestinal Incarceration---> situation where SI might incarcerate in a mesenteric rent?idiopathic, blunt trauma)
Small Intestinal Incarceration---> situation where SI might incarcerate through an inguinal ring?stallions & colts
Small Intestinal Incarceration---> which part of SI is most commonly involved in a epiploic foramen incarceration?Ileum most commonly involved
what are the 4 places an SI incarceration is likely to occur?Mesenteric rent, Inguinal ring, Gastrosplenic ligament, Epiploic foramen
cs of SI incarceration?acute colic
tx of SI incarceration?sx to resolve the entrapment
prog of SI incarceration?fair…..depending on timing of intervention
Potential post-op complications of SI incarceration?POI (post op ileus), Adhesion formation