Lecture 8 2/6/25 Flashcards
What are the characteristics of chronic enteropathy?
-greater than or equal to 2-3 weeks of gastrointestinal signs
-requires ruling out metabolic causes and maldigestion
-should evaluate a resting cortisol in all dogs and T4 in all older cats presenting with GI signs
What are the clinical manifestations of chronic enteropathy?
-diarrhea
-vomiting
-weight loss
-changes in appetite
-melena
-hematochezia
-tenesmus/straining
-hematemesis
-constipation
Which type of chronic enteropathy is responsible for the most cases?
food-responsive enteropathy
What does use of the term IBD imply in dogs?
-exclusion of extra-GI dz
-exclusion of parasitism
-exclusion of diet-responsive dz
-exclusion of antibiotic-responsive dz
-confirmation of inflammation on intestinal biopsy
-requirement for immune-modulators
What is chronic enteropathy used to describe?
chronic GI signs for which an underlying etiology has not yet been determined
What is protein-losing enteropathy?
small intestinal malabsorptive syndrome characterized by excessive protein loss, including hypoalbuminemia and hypoglobulinemia +/- hypocholesterolemia
What are the possible pathophysiologies/etiologies of protein-losing enteropathy?
-increased mucosal permeability due to inflammatory or neoplastic infiltration
-mechanical causes; ulcers, erosion, congestion
-lymphatic obstruction or rupture; lymphangiectasia w/ low cholesterol
What are the severe chronic enteropathies that can cause PLE?
-lymphoplasmacytic enteritis
-lymphangiectasia
-alimentary lymphoma
-infectious enteropathies
What are the clinical signs of protein losing enteropathy?
-small intestinal diarrhea
-weight loss despite good appetite
-panhypoproteinemia
-edema/pleural effusion/peritoneal effusion
-hypercoagulability
-refractory to treatment
What is lymphangiectasia?
subtype of protein-losing enteropathy in which there is both panhypoproteinemia and hypocholesterolemia
What are patients with lymphangiectasia at risk for?
hypocalcemia secondary to vitamin D malabsorption
What can be seen on abdominal ultrasound in patients with lymphangiectasia?
striations perpendicular to the intestinal lumen
What are the clin path findings in an uncomplicated chronic enteropathy?
-possible weight loss
-normal serum proteins
-normal cholesterol
-no third spacing
-normal electrolytes
What is the treatment for uncomplicated chronic enteropathy?
elimination diet +/- glucocorticoids
What are the clin path findings in protein-losing enteropathy?
-weight loss that may be profound
-panhypoproteinemia
-normal to low cholesterol
-edema and effusions if albumin is severely low
-normal electrolytes
What is the treatment for protein-losing enteropathy?
-elimination diet
-glucocorticoids +/- second agent
-manage risk of thrombosis
What are the clin path findings in lymphangiectasia?
-weight loss that may be profound
-panhypoproteinemia
-low cholesterol
-peritoneal and pleural effusion regardless of how low albumin is
-ionized hypocalcemia possible
What is the treatment for lymphangiectasia?
-low fat diet +/- elimination
-glucocorticoids +/- second agent
-manage risk of thrombosis
What is the minimum database when working up chronic enteropathy?
-CBC
-biochem panel
-UA +/- UPC
What are the characteristics of hypocalcemia in protein-losing enteropathy?
-decreased calcium is possible
-often low total calcium since hypoalbuminemia decreases total calcium
-confirm with ionized calcium measurement to determine if functional calcium is truly low
What are the characteristics of abdominal radiographs as a diagnostic tool for chronic enteropathy?
-often unrewarding
-screens for concurrent dz and obstructions
-may find gas and/or fluid in intestinal loops
-does not allow for evaluation of intestinal wall thickness and structure
What are the goals of abdominal ultrasound as a diagnostic tool for chronic enteropathy?
-screen for underlying and concurrent dz
-assess GI tract and associated lymph nodes; look for masses, wall thickness abnormalities, and wall layering abnormalities
-presence/absence of intestinal wall thickening does not rule chronic enteropathy in or out
What does a thickened intestinal muscularis on ultrasound indicate?
severe inflammation or small cell GI lymphoma; cannot differentiate on ultrasound
What does loss of normal layering on ultrasound indicate?
severe inflammation or neoplasia; cannot differentiate on ultrasound
What do mucosal hyperechoic striations perpendicular to the lumen indicate on ultrasound?
-increased suspicion of lymphangiectasia
-can be a normal postprandial change
Why should all patients with chronic diarrhea be dewormed (unless contraindicated)?
fecal testing is not 100% sensitive; it is better to empirically deworm than to miss a parasite causing clinical signs
Which anthelmintic medications can be used for empirical deworming in patients with chronic enteropathy?
-fenbendazole
-drontal plus
-profender
Why is endoscopy not routinely done as an early diagnostic tool in chronic enteropathy cases?
biopsy results can look the same for many different etiologies; treatment trials are often better for making an accurate diagnosis
When should a biopsy be obtained in chronic enteropathy workup?
-once food-responsive enteropathy, parasites, and idiopathic dysbiosis have been ruled out as potential causes
-when IBD, lymphangiectasia, and neoplasia are remaining possible differentials
-after completing therapeutic trials in patients that are stable, eating, and otherwise well
Which patients have an indication for an earlier biopsy?
-hyporexic or anorexic patients
-patients with 10% or greater unintended weight loss
-moderate to severe hypoalbuminemia
-young boxers and french bulldogs
-loss of intestinal wall layering, especially if focal
Why are biopsies typically sought earlier in a patient with protein-losing enteropathy?
-dropping albumin puts pressure on the timeline
-patient is more stable early on
-allows for early diagnosis and initiation of proper treatment
-rules out lymphoma and histoplasmosis early
What is the caution in doing biopsies in patients with protein-losing enteropathy?
albumin is important for healing; want to avoid full thickness biopsies when possible
What signs can help you to localize dz prior to doing a biopsy?
-small vs large bowel diarrhea
-serum folate and cobalamin measurements
-abdominal ultrasound findings
Which GI locations can be biopsied via scope?
-gastric (upper GI scope)
-duodenal (upper GI scope)
-ileum (lower GI scope)
-colon (lower GI scope)
Which GI location always requires surgical biopsy?
jejunum
What are the characteristics of endoscopic biopsy?
-no incisions
-faster recovery
-can access esophagus, stomach, duodenum, and ileum w/ minimally invasive procedure
-no full thickness biopsies; better healing, but chance to miss dz
-can biopsy multiple sites per segment
What are the characteristics of surgical biopsy?
-chance for poor healing, especially with low albumin
-longer recovery
-provides access to jejunum, liver, pancreas, associated lymph nodes, and potential masses
-allows for full thickness biopsies
-typically can only biopsy one site per segment
Which intestinal neoplasias are most common?
-intestinal adenocarcinomas
-gastrointestinal lymphoma
What are the clinical signs of intestinal neoplasia?
-non-specific GI signs
-anorexia
-weight loss
-vomiting and/or diarrhea
-possible hematochezia and/or melena
How is intestinal neoplasia diagnosed?
-palpation of mass or diffuse intestinal thickening
-rectal exam to find polyps and adenocarcinomas
-abdominal radiographs
-abdominal ultrasound
-cytology
-histopathology
What is the treatment of choice for intestinal adenocarcinoma?
surgery
What is the treatment of choice for high grade/large cell GI lymphoma?
chemotherapy +/- surgery
What is the treatment of choice for low grade/small cell GI lymphoma?
chemotherapy
