GI - Ex 4

Question 1

Three fecal screening tests

Answer 1

Examination for parasites - fecal float or Baermann technique

Fecal blood: occult (upper GI) and grossly visible (lower)

Fecal cytology

Question 2

Fecal Occult Blood

Answer 2

20-50x more sensitive than gross examination

*Measure pseudoperoxidase activity of Hgb

• Can get false positive: meat diet, vegetables that contain pseudoperoxidase
• Dietary restriction for 3 days prior!

*Can get false negative: high fluid content can dilute blood, blood not uniformly distributed in sample, or reader error

Question 3

Fecal Cytology

Answer 3

Inflammation - indicates colonic inflammation (neutrophils normally not present)

Neoplasia - rarely found; if found indicates colonic origin

Microflora - heterogenous normally; if homogeneity –> suggests over growth

Question 4

Clostridial spores in feces

Answer 4

Gram +, spore forming anaerobe; “Safety Pin”

Release enterotoxins –> cause diarrhea

• **No correlation between number of spores noted and C. perfringens entertain levels
• “normal” dogs have spores

Question 5

The Pancreas Functions

Answer 5

Exocrine: synthesis/secretion of digestive enzymes (6)
- trypsinogen, chymotrypsinogen, proelastase, procarboxypeptidases, lipase, and amylase

Endocrine: insulin & glucagon secretion –> glucose regulation

Question 6

Digestion/Absorption

Answer 6

• EPI
• results in inadequate food DIGESTION
• Need to differentiate from malabsorption
• intestinal dz prevents absorption
• EPI usually normal protein; malabsorption usually hypoproteinemia

*Clinical signs of maldigestion and malabsorption are similar

Question 7

EPI - Maldigestion

Answer 7

• EPI
• Pancreatic Acinar Atrophy
• Chronic pancreatitis
• Generally voluminous, poorly formed stool
• Weight loss
• BW may not be helpful

*BEST TEST = TLI

Question 8

Malabsorption

Answer 8

• Intestinal dz
• generally diffuse, severe
• can be inflammatory, neoplastic, congenital
• Generally voluminous, poorly formed stool
• Weight loss
• *Can see severe HYPOPROTEINEMIA - GI loss
• depends on duration, severity

Question 9

Fecal Fat

Answer 9

*Generally used to screen for undigested fats

Positive = undigested fats present –> maldigestion –> EPI suggested

*Very insensitive! Many EPI animals will not have detectable fat in their feces

Question 10

TLI

Answer 10

Most sensitive and specific test for EPI

Question 11

TLI - Dogs

Answer 11

< 2.5 = EPI
> 5.0 = malabsorption (intestinal dz)

2. 5-5.0 = gray zone –> repeat assay in a few weeks
   - sample exposed to extreme heat in transit, recovering from pancreatitis, food not withheld properly, or early EPI

Question 12

TLI in Cats

Answer 12

Levels <8.0 = EPI

Question 13

Absorption of B12 and Folate

Answer 13

Folate = proximal SI

B12 = distal SI

Question 14

B12 and Folate both decreased

Answer 14

Generalized malabsorption

EPI in cats may mimic malabsorption

Question 15

Decreased folate, normal B12

Answer 15

Proximal SI defect

Question 16

Decreased B12, normal folate

Answer 16

Distal SI defect

Question 17

Cats, EPI, and Folate/B12

Answer 17

EPI –> dec Intrinsic Factor release (IF necessary for B12 absorption) –> dec B12 absorption

Intestinal dz may accompany EPI –> dec folate

If above happens together you have dec B12 AND dec folate! This will appear as malabsorption

Question 18

Increased Folate and decreased B12

Answer 18

Bacterial overgrowth

• intestinal bacteria can synthesize folate and bind B12 and prevent its absorption

**Dogs with confirmed bacterial overgrowth can have normal folate, B12 levels