10.25.96------start here--------- clinical correlation; dr JAMES orsini GI tract of the horse. draft horses: at risk for airway, orthopedic and GI problems foals: respiratory probs, urogenital, gi probs common Surgical History: 70% of useful diagnostic information is from the history 20% from the physical exam about 10% of useful info is from lab tests. it is very important to LISTEN to the owner and take a good history. dr. orsini remarks this is something MEN in particular need to work on... case: two horses pastured in maryland, in a field fenced with rubber fencing (was popular because of recycling). But, horses would chew on the rubber fencing, which didn't seem to be a big deal, but over time, the fencing would fray and be ingested, and these tiny fragments over time would cause a colic, by causing a blockage of the GI tract. If you didn't ask about housing, you could have missed this diagnosis... "let's wait and see how he is tomorrow" - procrastination. the wait and see attitude can in many cases be worthwhile, but can also result in a dead animal. back in the 60s and 70s people didn't realize colic was life threatening, and animals would present to new bolton in an already terminal condition. GI tract of horse very extensive. Small intestine is 70 ft long. sm intestine can herniate through epiploic foramen, can herniate through inguinal ring, through a rip in the mesentery, can get distended, twist, etc. the cecum can weigh 50 lbs when full. the Large intestine can also be 50 or more pounds when full. this can be a surgeons worst nightmare. and of course, because of the depth of the abdomen, you can't exteriorize the pylorus, or the stomach. via rectal exam,you can really only palpate the caudal third of the abd. left kidney, colon, bladder, uterus, ovaries, parts of small intestine IF distended, inguinal rings... the ileum is a part of small intestine that is hard to exteriorize. the ileum, because it acually enters the cecum at the base, the part you see is near the distal jejunum. the ileum can sometimes intussuscept into the cecum, esp in young horses. it will go through the ileocecal valve, and cause an obstruction which must be reduced. you have to unblock this and possibly even make a bypass, if the obstruction has caused necrosis of the distal ileum. you can see ileal hypertrophy, which causes the lumen to constrict, and can predispose animal to obstruction. this would necessitate bypass surgery. you may see an area of infarction of the GI tract [slide- infarcted, perforate cecum] which can lead to a perforation of the intestine, leading to septic peritonitis. an abdominocentesis would be diagnostic for this, because you'd see increased white cells and bacteria in the abdominal fluid. [slide- twisted right ventral colon, looks dark purple, congested.] - tissue becomes necrotic and has to be removed, or if too much tissue, you have to euthanize the horse. ENTEROLITHS; Stones of the intestine. over time, some central irritant, eg piece of foreign material or food, forms concretions, or solid layers of mineral deposited on it, and can grow to be quite large stones, and they're fine if they occur in a place where they can pass, but, say, if in the pelvic flexure narrowing, or the transverse colon, could get stuck and act as ball valves, blocking the GI tract. these horses present with history of chronic colic, because the enteroliths can move into blocking position and back out, so pain is intermittent. the key is in treating these animals, there can be multiple stones, so you don't just stop after you find ONE. EXCEPTION- [slide- xeroradiograph of enterolith showing very radiodense center]. you might want to check some of the cadavers, they may have areas of intestinal infarct. COLIC: anything that causes abdominal pain. could be kidney stones. usually GI. CASE: SIGNS: one day to 4 mos age anorexia, depresion, teeth grinding/odontoprisis/bruxism, protrusion of tongue frothing at mouth, profuse salivation/sialorrhea, regurgitation of milk, gastric distention, severe abdominal distress, megaesophagus. DIAGNOSIS: barium rads of upper GI, based on age and clinical signs, normal abdominocentesis. if at 60 min barium not in cecum, it's probably being held up somewhere... if abdominocentesis is abnormal, there may be MORE disease occuring than can be appreciated from PE. [slide- barium stopping at distal end of esophagus, hallmark of blockage at the cardia. barium not flowing into the stomach. air is seen in the stomach. this foal has an esophageal obstruction] [slide- barium in esophagus, and in stomach, but esophagus is enlarged - barium is being refluxed BACK into esophagus. barium may come out nose in this case. more caudal film shows barium filling stomach w/large gas pocket dorsally, and no barium is going into the duodenum] [slide: barium in small intestine, gas in small intestine- stops at ileum. ileocecal intussusception]. can usually only get one view of the abdomen of a foal on xray, due to size considerations, and because they are standing, but you can usually do ok accuracy wise. surgical correction: if esophageal obstruction at cardia: relocate esophagus. may require thoracotomy and celiotomy. if abscess and obstruction at gastric antrum, resect antrum and pylorus followed by gastroduodensotomy (billroth I) if pyloric stenosis: gastroduodenostomy (jaboulay). duodenal stenosis: with normal sigmoid loop of duodenum and stricture beyond hepatopancreaticampulla, can do duodenojejunostomy, jejunojejunostomy. if duodenal stenosis with abnormal duodenum to caudal flexure, gastrojejunostomy, jejunojejunostomy. if duodenal stenosis with normal sigmoidloop of duodenum and abnormal ampulla, do duodenojejunostomy (5 cm stoma) choledochojejunostomy (2 cm stoma), jejunojejunostomy (7 cm stoma) when you do a duodenojejunostomy w/o doing a jejunojejunostomy, you end up still obstructed, because you pull up a loop of jejunum to attach it, at the top of an upsidedown U, but you have to have a way for stuff that goes down the proximal loop to get back into the distalloop. postop the baby is in the icu with pillows and blankets and fluids. these problems also occur in llamas, calves, etc. -----end----------