Specific Gastro- Intestinal Diseases Flashcards
What conditions are most frequently seen in the stomach?
Gastric dilation and impaction — highly fermentable feeds
Equine gastric ulcer syndrome —> can progress to stenosis
Neoplasia —SCC
T/F: the small intestine usually presents with strangulating disease
True
What are the non-strangulating small intestinal obstructions?
Ascarid inactions (often appear strangulating)
Small intestinal feed or foreign body impaction
Muscular hypertrophy
Abscess
Adhesions
Neoplasia
What is the signalment usually seen with ascarid impaction?
Young horses : weanlings/yearlings
Recent administration of very effective antheminitics
Clinical signs associated with small intestinal ascarid impaction?
Looks strangulating —> severe necrosis and inflammation by death of the worms
Toxic, shocky, moderate to severe colic
Can see worms on gastric reflux
What is the treatment for ascarid impaction?
Might required surgical intervention if complete obstruction
Severe necrosis of the small intestine is the normal
Conservative : laxatives (mineral oil) and IV fluids
Prevention: slow deworming
Where do small intestinal feed impactions usually occur?
Ileal
What feed is usually associated with feed impactions?
Bermuda gras
Fine hay particles
Clinical signs seen with SI feed or FB impactions?
Intermittent, partial, or complete obstrucion
Rectal : SI distention and can palpate impaction dorsally on the right just cranial to the cecum. As impaction progresses, it gets pulled out of reach
Treatment for SI feed/ FB impactions?
Conservative : laxatives (mineral oil), IV fluids, and analgesics
Surgical correction — post op ileus seen
What is the prognosis for SI feed/FB impactions?
Duration < 17hrs : likely to survive
Duration > 17hrs : usually die
What are causes of muscular hypertrophy of the SI ?
Primary (idiopathic)
Secondary - proximal hypertrophy associated with a distal stenosis
Risk factors for SI muscular hypertrophy?
Ileal impactions
Can be associated with tapeworms
Clinical signs of SI muscular hypertrophy?
Intermittent colic with mild to moderate pain after eating
Anorexia and weight loss
Treatment of SI muscular hypertrophy ?
If associate with tapeworms — pyrantel pamoate
Ileomyotomy
Side-to side ileocecal anastomosis (without resection)
Side-to-side jejunocecal anastomosis
How do abscesses cause SI obstructions?
Direct compression or stricture due to the abscesses or mass itself OR due to adhesions which result from the local inflammation
Signalment associated with abscesses resulting in SI obstructions?
Less than 5yrs
History of weight loss and/or unthriftiness
Clinical signs associated with abscesses causing SI obstrucion??
Depressed, anorexic, and febrile
Neutropenia with a left shift and hyperfibrogenemia
What do you usually see on an abdominocentesis of a horse with abscesses ?
Elevated protein and WBC count
Intracellular or fee of bacteria occur only rarely
Usually — strep zooepidemicus, strep equi, rhodococcus equi, and cornybacterium pseudotuberculosis
Treatment for abdominal abscessation?
Conservative : long term antibiotics are the treatment of choice — has guarded prognosis
Surgical
— removal of abscess and/or affected bowel
— marsupilaization of abscess
— by-pass affected bowel
T/F: adhesions can occur in either the LI or SI, but are of more significance in the SI?
True
SI has many hair-pin curves and tight adhesions are more likely to cause significant obstruction
What causes of inflammation can lead to adhesions ?
Infection
Foreign body
Vascular insufficiency
Peritonitis — usually resulting from microbial contamination of abdomen
What can peritonitis be caused by?
Previous abdominal surgery
Parasitic larval migration
Abdominal abscessation
Interstitial ischemia
Clinical signs associated with a intestinal obstruction caused by adhesions?
History of recurrent episodes of colic
Usually responsive to medical therapy until severe obstruction
Can have severe unresponsive pain
Treatment for intestinal obstrucion caused by adhesions?
Reception of adhesions and involved bowl
By-pass
Guarded to poor prognosis, recurrence is a major problem
What are the two most important neoplasms of the equine abdomen?
Squamous cell carcinoma a
Lymphosarcoma
What are causes of a strangulating SI obstructions?
Volvulus Strangulating lipoma Internal hernia - epiploic foramen - gastrospelnic ligament - mesenteric defect External hernia -inguinal -umbilical -diaphragmatic Intussusception
Signalment associated with SI volvulus?
<3yrs
If <1yr, associated with change in diet or ascarid infection
SI volvulus may be secondary to other conditions that result in a fulcrum. What are some of these conditons>?
Mesodiverticuar bands (embryonic remnant of vitelline circulation)
Meckel’s diverticulum (embryonic remnant of omphalomesenteric duct)
Adhesions
Hernias— inguinal, mesenteric
Signalment associated with strangulating lipoma?
Older horse > 9-10yrs
Peducutated - fat masses on the end of a fibrovascular stock
What are the boundaries of the epiploic foramen?
Dorsal: caudate lobe of the liver and vena cava
Ventral: right lobe of the pancreas, gastropancreatic fold and portal vein
Cranial: hepatoduodenal ligament
Caudal : intersection of the pancreas and mesodudodenum
What are two mechanisms that epiploic foramen entrapment can occur?
Right to left passage of intestine from right of midline through foramen into the omental bursa
Left to right passage of bowel ruptures the omentum and pushes through the foramen
What are risk factors for epiploic foramen entrapment?
Older horse: reduction in size of liver results in enlargement of space
Cribbing
Clinical signs of epiploic foramen entrapment?
Rectal exam
SI distention with fewer loops than you would expect
Peritoneal fluid can be misleading — only abnormal isn 56% of cases
What is the treatment for epiploic foramen entrapment?
Surgical correction
But can result in immediate death of the horse (particular complicating factor for this surgery) —> due to inflammation, local damage, and necrosis you can have rupture of the caudal cava or portal vein
Where is the gastrosplenic ligament located?
From left part of greater curvature of the stomach t the hilus of the spleen
With gastrosplenic ligament entrapment, which part of the SI is usually trapped?
Distal jejunum and ileum
What is the signalment fo inguinal hernias?
Newborn colts
Breeding stallions: usually after breeding or significant physical exertion
Standardbreds, saddlebreds, and Tennessee walkers
Clinical signs of inguinal hernia?
Usually unilateral and indirect in stallions (within vaginal tunic)
Newborns
Indirect — reducible, non-painful
Direct (outside the vaginal tunic, in SQ tissue, passing through rent in peritoneum or fascia)
Acute and painful
Rectal palpation— intestine through vaginal ring
What are predisposing factors for umbilical hernias?
Manual breaking of the umbilical cord
Umbilical infection
Excessive straining
Ligation of cord
When are umbilical hernias in need of surgical correction?
If there is increase in size of hernia
If presence of firmness, warmth, edema
If presence of pain on palpation of the area
What are causes of diaphragmatic hernias ?
Congenital
Trauma
Increased intraabomdinal pressure: blow, parturition, severe GI distention or strenuous exercises
T/F: horses usually present only with GI signs with diaphragmatic hernias, respiratory dysfunction is not commonly seen
True
What are predisposing causes to intussusception?
Dietary change Heavy ascarid infection Enteritis Previous SI surgery Anthelmitic administration Tapeworm infestation Intramural tumors Obstruction secondary to foreign body— luminal polyp
T/F: intussusception is more common in older horses
False usually <3yrs
What portion of the intestine is most frequently involved in intussusception?
Ileum and ileocecal junction
The subacute form of intussusception is associated with what clinical sign in foals?
Diarrhea
Why would peritoneal fluid changes not reflect the degree of necrosis caused by intussusception ?
Because the “dead” bowl is inside another piece of bowel and isolated from peritoneal cavity
What inflammatory disease is a major differential for what appears to be a strangulating lesion of the SI?
Dudodenitis proximal jejunitis (DPJ)
What are the disease characteristics of duodentitis proximal jejunitis (DPJ) ?
Inflammation and edema of the duodenum and variably the stomach and jejunum
Signalment associated with DPJ?
Mostly adults especially those on a high plain of nutrition
What bacteria is thought to be involved with DPJ?
Salmonella and or clostridia (c.difficile)
Clinical signs seen with DPJ?
Moderate to severe pain with copious amounts of NG reflux, often with orange-brown fetid odor
Initial volumes may reach 12-16L
Pain usually subsides after decompression but most horses remain depressed
Abdominocentesis results that could indicate DPJ?
Increased TP
Mild to moderate WBC
Fluid yellow-turbid, in severe cases RBC might be present
What are the two major components of therapy for DPJ?
Gastric decompression — every 1-2hrs
Fluid administration — CV support
You want to give your DPJ horse something to treat endotoxemia .. what can you administer?
Polymixin B or endoserum
Lidocaine
DMSO
NSAIDS — flunixin
T/F: we give DPJ horse antibiotics as part of their therapy to treat the enteritis
False
—given to cover systemic effects of altered mucosa
Use penicillin due to possible association of clostridum
T/F: motility drugs are used in cases of DPJ?
True
In cases of persistent reflux
IV lidocaine
Common complications assoicated with DPJ ?
Peritonitis Myocardial and renal infarction Aspiration pneumonia Adhesions of small intestine Laminitis
What is usually responsible for thromboembolic injury resulting in necrotic, comprised bowel segments ?
Large strongly —> cranial mesenteric arteries
Vasculitis, purpura and DIC can also result in thrombosis
