Intestinal Lab Evaluation Flashcards
If fecal blood is grossly visible, where is the origin of the bleed?
Lower GI (colonic)
If fecal blood is occult, where is the origin of the bleeding?
Upper GI (melena)
What are indications the there is fecal occult blood?
Unexplained diarrhea or loose stool
Unexplained microcytic anemia
Ulcerogenic drugs
History of GI tract tumors
Fecal occult blood measures ________________ and is 20-50x more sensitive than gross examination
Pseudoperoxidase activity of hemoglobin
What can cause a false positive fecal occult blood test?
Myoglobin/hemoglobin in meats
Some fresh vegetables contain peroxidase
–> dietary restriction for 3 days prior
What can cause false negative fecal occult blood tests?
High vit C intake
High fluid content can dilute blood
Blood is not uniformly distributed in sample
Reader error
In a fecal cytology, you see neutrophils, what is this due to?
Colonic inflmmation
Eosinophils can be present in fecal cytology in what condition?
Eosinophilic colitis
T/F: a pleomorphic population of bacteria in the GI tract is indicative of infection?
False
Pleomorphic is normal
Uniform–> abnormal overgrowth
What appears as a safety pin in a fecal cytology?
Clostridium spore
What bacteria is “gull winged” shaped in a fecal cytology
Campylobacter
What is the difference between exocrine pancreatic insufficiency (EPI) and malabsorption
EPI = inadequate food digestion
Malabsorption = disease preventing absorption
Exocrine pancreastic insufficiency in dogs is usually due to??
Pancreatic acinar atrophy -immune mediated destruction of pancreas
What are the causes of maldigestion?
Exocrine pancreatic insufficiency
Bile acid insufficiency (rare)
Chronic biliary obstruction
Serum bile acids increased
Is it malabsorption or maldigestion?
Voluminous, poorly formed stool, flatulence, and foul odor
Maldigestion
Is it malabsorption or maldigestion?
Voluminous, poorly formed gray feces
Maldigestion
What tests are used for digestion/absorption screening?
Fecal starch
Fecal fat
Fecal proteolytic activity
Plasma turbidity test
What is a sensitive and specific test for EPI ?
Trypsin-like immunoreactivity (TLI)
In dog and cat, a small amount of trysoinogen continually escapes from pancrease
TLI > 5.0ug/L is ?
Normal
A TLI <2.5 ug/L is?
EPI
A TLI that is 2.55.0 ug/L is in the “gray zone” what can cause this?
Sample exposure to extreme heat
Recovering from pancreatitis
Food not withheld appropriately
Early EPI
->repeat in a few weeks
In cats, a TLI of _____ug/L is highly specific for EPI
<8
4yr old FS Golden retriever mix
Loose stools, malodorous
Polyphagia
PE: thin, quiet, poor haircoat
TLI = <0.5ug/L
Exocrine pancreatic insufficiency
Folate is absorbed in the ______________ and B12 is absorbed in the _______________
Jejunum; ileum
If both vitamin B12 and folate are decreased where is the malabsorption occurring?
Generalized
If folate is decreased and B12 is normal, where is the malabsorption occurring?
Proximal SI defect (jejunum)
If folate is normal and B12 is decreased, where is the malabsorption?
Distal SI defect ( ileum )
What are your two DDx for a decrease in folate and B12 in a cat?
Generalized malabsorption
EPI -> pancreas produce IF(required for B12 absorption) and intestinal disease can accompany EPI causing decreased folate –> mimicking malabsorption
Do dogs with EPI usually have changes in folate and B12 levels ?
B12 may be slightly decreased, but stomach secretes some IF
Folate is normal to increased because bacterial overgrowth is common in dogs with EPI (also can cause further B12 reduction)
Increased folate and decreased B12 indicates?
Bacterial overgrowth
Bacteria bind B12 and prevent absorption and synthesize folate
What protein is normally found in plasma but concentration within the GI lumen can occur in protein losing enteropathy
Fecal a1-protease inhibitor
Dog with chronic loose, gray-coloured stoo;
Bile acids - normal
TLI 2.5
Folate 8.0 -normal
Cobalmin 210 - decreased
Exocrine pancreatic insufficiency
Dog with chronic loose stool and weight loss
Bile acids- normal
TLI 8.1 -normal
Folate 3.2-low
Cobalamin 110- low
Generalized malabsorption
T/F: High vomiting due to pyloric obstruction can result in a metabolic alkalosis
True
Loss of HCl
