Lecture 7 2/6/25 Flashcards
What is the general overview of chronic small bowel diarrhea?
-3 weeks or longer in duration
-can be accompanied by other clinical signs; vomiting, weight loss, changes in appetite, melena/hematemesis/hematochezia
-requires a diagnostic workup
What are the extra-GI causes of chronic small bowel diarrhea?
-hepatic dz
-pancreatic dz
-renal dz
-endocrine dz
-hypercalcemia
-underlying dz such as neoplasia or systemic infection
What is the primary GI cause of chronic small bowel diarrhea?
chronic enteropathy
What conditions fall under chronic enteropathy?
-endoparasites
-food-responsive enteropathy
-microbiota modulation responsive enteropathy/idiopathic dysbiosis
-lymphangiectasia
-immunosuppressant responsive enteropathy/IBD
-non-responsive enteropathy
-GI lymphoma
-fungal infections
What are the characteristics of hypoadrenocorticism/Addison’s disease as a cause of diarrhea in dogs?
-seen in 4% of dogs with chronic GI signs
-classical hypoadrenocorticism involves deficiencies in glucocorticoids and mineralocorticoids
-atypical hypoadrenocorticism involves deficiency in just glucocorticoids
What findings should increase suspicion of Addison’s disease in dogs?
-signalment; typically female, predisposed breeds
-intermittent GI signs
-lack of stress leukogram
-lymphocytosis
-increased K and decreased Na
How is Addison’s disease diagnosed?
-resting cortisol measurement
-measurements >2 ug/dl rules out Addison’s
-measurements < 2 ug/dl indicates need for an ACTH stimulation test
What findings should increase suspicion of hyperthyroidism in cats?
-older cats
-concurrent weight loss
-CBC and chem abnormalities; especially elevated liver enzymes
How is hyperthyroidism diagnosed?
-total T4 measurement
-thyroid scintigraphy
What are the differentials for weight loss despite a good appetite?
-inadequate caloric intake
-maldigestion
-malabsorption
-diabetes mellitus
-energy consumptive dz
What is the main goal when doing a diagnostic approach to chronic small bowel diarrhea?
-narrow down the differential list
-rule out diseases
-screen for clin path data that supports differentials
What does an inflammatory leukogram with left shift indicate for a patient with chronic small bowel diarrhea?
need for aggressive diagnostics and therapeutics
What does marked anemia indicate for a patient with chronic small bowel diarrhea?
possibility of GI bleeding; should be imaged sooner and possibly started on blood transfusions
What does erythrocytosis indicate for a patient with chronic small bowel diarrhea?
hemoconcentration and a need for fluid therapy
Which changes on a CBC aid in ordering the differentials list?
-lack of stress leukogram (Addison’s)
-eosinophilia
What does eosinophilia correlate with in chronic small bowel diarrhea patients?
-parasites
-food allergies
-mast cell cancer
-hypoadrenocorticism
What are the possible anemia types seen in chronic SI diarrhea animals?
-regenerative, macrocytic, hypochromic: indicates regenerative anemia from hemorrhage
-non-regenerative, microcytic, hypochromic: indicates iron deficiency anemia and chronicity
-reticulocytosis without anemia: indicates increased RBC turnover
Which findings on the chem panel indicate extra-GI disease?
-azotemia: kidney dz
-elevated liver enzymes: hepatic dz
-hyperglycemia: diabetic ketoacidosis/diabetes
-hypercalcemia
What are the characteristics of reactive hepatopathy?
-dogs only
-ALT and ALP increase; 2-4x normal
-no increase in TBili
-no evidence of liver dysfunction; glucose, urea, albumin, and cholesterol are normal
How does hypokalemia influence treatment?
patient should be supplemented with IV fluids and nutritional support
How does a finding of severe hypoalbuminemia influence treatment?
-IV fluids has an increased risk of third-spacing
-can see edema and/or cavitary effusion
-negative prognostic indicator in dogs with chronic enteropathy
What are the characteristics of increased BUN?
-can be indicative of GI bleeding
-can concurrently see anemia/inappropriate reticulocytosis, thrombocytosis, melena, and/or hematemesis
What are the characteristics of panhypoproteinemia?
-indicates malabsorptive disease
-decreased albumin and globulin due to protein-losing enteropathy
-can see hypocholesterolemia in patients with concurrent lymphangiectasia
What are the causes of decreased albumin?
-decreased production
-loss
-sequestration
What are the characteristics of globulins?
-includes non-albumin proteins, immunoglobulins, and acute phase proteins
-larger than albumin
-glomerulus is is selective; less likely to be filtered compared to albumin
What are the findings associated with protein losing enteropathy?
-low albumin
-low globulins; can be normal or high w/ inflammation
-low cholesterol
-decreased cobalamin
-changes in folate
-diagnosed through deworming, diet/probiotic trials, and biopsy
What are the findings associated with protein losing nephropathy?
-low albumin
-normal globulins; can be high w/ inflammation
-normal cholesterol; can be high w/ inflammation
-azotemia and glucosuria
-diagnosed through UA and urine protein-creatinine ratio
What are the findings associated with liver dysfunction?
-low albumin
-normal globulins; can be high with inflammation
-low cholesterol
-low urea and glucose
-high Tbili and PT/PTT (low clotting factors)
-diagnosed through bile acids and NH3 measurements
What are the characteristics of urinalysis in patients with chronic SI diarrhea?
-often normal
-used to screen for concurrent dz
-must be performed in patients with hypoalbuminemia to determine if loss is via the kidneys
What are the characteristics of fecal testing?
-should be done in all patients with chronic GI signs
-ideally want a large, non-diarrheal sample
-can do a sugar/routine float or a zinc/giardia float
-ideally repeat exam 3 times
-treat all identified parasites appropriately
Which tests are used to rule out pancreatitis?
-SNAP cPL test
-pancreatic lipase immunoreactivity/PLI
Which disease causes maldigestion?
exocrine pancreatic insufficiency
Which diseases cause malabsorption?
-food-responsive enteropathy
-antibiotic-responsive enteropathy
-lymphangiectasia
-immunosuppressant-responsive enteropathy
-GI lymphoma
Which B vitamins are evaluated to identify malabsorptive disease?
-cobalamin, vit. B12
-folate, vit. B9
What are the characteristics of folate?
-absorbed in proximal SI
-decreased in malabsorptive dz of duodenum
-increased in bacterial overgrowth of upper SI (produced by bact.)
What are the characteristics of cobalamin?
-absorbed in distal SI/ileum
-decreased in malabsorptive dz of ileum and bacterial overgrowth of SI (used by bact.)
What are the characteristics of cobalamin supplementation?
-should be done when serum conc. is in the low normal range; less than 400 ng/L
-can be done parenterally or orally
What is important regarding folate supplementation?
benefit of supplementation has not been demonstrated
What are the characteristics of the trypsin-like immunoreactivity test?
-sensitive and specific test for maldigestion
-species specific
-requires 8-12 hour fast and non-hemolyzed serum
-low values diagnostic for exocrine pancreatic insufficiency
