Equine Med- Chronic diarrhea

wilsbach's version from 2016-02-22 18:52


Question Answer
once again, list of things which cause ACUTE diarrhea? Salmonella spp, Clostridium spp., Antimicrobial associated, Potomac Horse Fever, Blister Beetle Toxicosis, grain overload
once again, list of things which cause CHRONIC diarrhea?Salmonella spp. (can be acute or chronic), Sand enteropathy, NSAID toxicosis, Parasites, (IBD), (neoplasia), (peritonitis). (dont think we're going over parenthesis ones)
how might the diarrhea itself vary between acute and chronic type? Not as watery / profuse as acute diarrhea. May be intermittent / seasonal
are systemic signs more prevalent in acute or chronic diarrhea?systemic signs more prevalent in in ACUTE
what is appetite/ temperature like in a horse with CHRONIC diarrhea?both normal
what will hematology usually look like with chronic diarrhea?usually normal, might see some hypoproteinemia.

Chronic Salmonellosis, Sand Enteropathy/colic

Question Answer
why is this salmonellosis "chronic"? Prolonged fecal shedding after acute phase
what is the main problem with chronic form of salmonellosis?NOT a huge risk for the horse itself, however, they are a Constant source of contamination and Can cause acute clinical cases in other horses
dx of chronic salmonellosis?same as acute-- (PCR of feces is the best way, culture difficult due to intermittent shedding)
risk factors for sand colic Environments with sandy soils. Also ingested during normal grazing / or from ground feeding
where does ingested sand tend to finally settle down?down into ventral colons.
what is the pathophys of sand colic?sand settles in ventral colons--> Mechanical irritation of colonic mucosa. Can also develop obstruction --> Colic
how would you describe the diarrhea caused by sand? Diarrhea is not severe, May be intermittent / seasonal.
how can you dx sand colic? (4)(1) auscultation: “waves on the shore” (2) Fecal float for sand (multiple times!) (not sure if this includes the glove technique but don't forget that) (3) Ultrasonography (4) X-Ray of ventral abdomen
What might sand colic sound like if you ascult the abdomen?waves on a shore
how do you tx sand colic... and what is the focus of the treatment? Oral and IV fluids (overhydration), NSAIDs to decrease inflammation & control pain... main treatment is directed toward removing sand and ingesta from colon OVER TIME!: Psyllium (Metamucil / Sand clear)
how quickly do you want to remove sand from the GI?SLoWLY!!!!!! sx is rare and risky! Rather, use Psyllium (Metamucil / Sand clear) to slowly remove it.
what are the main complications of sand colic?endotoxemia--> laminitis
when would you consider sx intervention for sand colic? what do you do?consider sx if there is uncontrollable pain. remove the sand via Pelvic flexure enterotomy
how can you help prevent sand colic?Management changes are vital!!!! put Hay in racks / bins, Tarp / carpet or mat beneath the food, Avoid overgrazing pastures, Prophylactic psyllium administration


Question Answer
what are the two NSAIDs which are the main suspects in RDC?Phenylbutazone / flunixine meglumine
how do the NSAIDs cause RDC (pathophys)Cause mucosal ulcers through inhibition of the cyclo-oxygenase pathway of the arachidonic acid cascade: PG’s ↓.... PG’s regulate mucosal blood flow in the stomach, colon, and kidney so altering blood flow can lead to the colitis. (there is a Individual variation in sensitivity )
of Phenylbutazone / flunixine meglumine, which is more likely to cause the ulcers? Phenylbutazone > Flunixine meglumine (bute is the worst-- remember group example from 3rd term)
NSAIDs can cause ulcers all long the GI...what are the most common places?Oral and lingual ulcers rarely occur, GASTRIC ulcers more common, and Right Dorsal Colitis (RDC) is the MOST COMMON (And often only place) affected.
right dorsal colitis can lead to what problems?can cause Protein loosing enteropathy, Can cause acute or chronic intermittent colic
what are the clinical signs of ACUTE RDC? CHRONIC?ACUTE: colic, endotoxemia... Depends on size ulcer(s) .. CHRONIC: protein losing enteropathy, diarrhea (so you can see ventral edema from PLE)
most sensitive part of GI to NSAIDs is..RDC!!
what blood work might support a suspicion of RDC?Albumin loss (protein losing enteropathy), Neutropenia may be present, Elevated fibrinogen (inflammatory marker)
what will you see on US that is supportive evidence for RDC? (and where are you ultrasounding?) Thickened RDC wall (12-15 ICS) is supportive evidence (> 0.5cm)
how do you tx RDC?Immediate discontinuation of NSAIDs!!!! + Supportive care for colitis...also do Dietary modifications (less roughage and more complete pelleted feeds), Corn oil (linoleic acid) (Aids mucosal healing), Synthetic prostaglandins
what dietary modifications would you like to use as therapy for a RDC horse, and why?Restrict long stem fibers / roughage, and give more Complete pelleted feeds (this decreases the mechanical load the colon has to bear)
What can you give to tx the RDC horse which aids in mucosal healing?corn oil (has linoleic acid)
why do you wanna give Synthetic prostaglandins and what is an example of one?bc NSAIDs inhibit COX so PGs not made, and PGs are what control blood flow to you can give PGs directly to help support bloodflow. One such PG is misoprostol (2ug/kg PO q 6-8 hours)
how should you manage the pain of RDC?NO NSAIDS LOLOLOLOL. you can give opioids (morphine- with caution- or Butorphanol intermittently). You can also give lidocaine 2% CRI.
if you provide pain management for the RDC horse and you cannot get it controlled, what should you consider? Uncontrollable pain may indicate exploratory laparotomy--> Colonic resection or bypass
what are the complications of RDC? (prog?)COMPLICATIONS INCLUDE: laminitis, colon rupture, colonic infarction, Colonic stricture. (guarded prognosis)


Question Answer
what is CYATHOSTOMIASIS caused by?Small Strongyles
what is the lifecycle of small strongyles/CYATHOSTOMES?
what is the pathophys of cyathostomiasis?Adult worm lives in colon. Encysted larvae cause damage when hatching out of the gut wall
what is the seasonality of cyathostomiasis like?End winter / early spring (northern areas) (think of it as They are coming out of "hypobiosis")
how might bloodwork be affected by cyathostomiasis?hypoproteinemia (protein lost to gut bc mucosal damage?)
how do you dx cyathostomiasis? FEC / FEC reduction test (consider encysted cyathostomes though- might have to just look for response to deworming)
what dewormers could you consider to tx cyathostomes? Moxidectin (little resistance), Fenbendazole (5 days 10mg/kg PO q24h)