Ch 48 Large intestine

Question 1

Which species has a distinct ileocolic and cecocolic valve?

Answer 1

canine

Question 2

which is feline and which is canine?

Answer 2

A canine
B feline

Question 3

What are the 4 theories of pneumatosis coli?

Answer 3

Bacterial, Mechanical, Mucosal damage, Pulmonary disease

Question 4

Answer 4

Question 5

Answer 5

Narrowing and irregularity of the descending colon are present immediately cranial to the air- inflated catheter cuff. This was due to spasm associated with insertion of the catheter. B, The spasm was transient based on a subsequent radiograph made several minutes later.

Question 6

Dose for barium enema to fill entire colon

Answer 6

7-15 ml/kg

Question 7

Which radiographic technique might help for subtle mucosal lesions of the colon?

Answer 7

double-contrast study performed by removing as much of the barium as possible and then inflating the colon with room air through the catheter

Question 8

What should be differentiated from ulcers in the canine colon, and feline colon and cecum?

Answer 8

mucosal lymph follicles; they can appear as spicules (barium enema) or pinpoint radiopacities (double contrast)

Question 9

Can you evaluate the colon after per os barium?

Answer 9

No, there is inadequate distension and there will be filling defects from ingesta/faeces

Question 10

Which contrast is normally used for an enema study, and which if a colonic rupture is suspected?

Answer 10

Barium for a routine (barium) enema study
15-20% non-ionic aqueous iodine for suspected rupture

Question 11

What is the downside of using aqueous iodine as contrast when colonic rupture is suspected?

Answer 11

Mucosal detail will be diminished compared to barium

Question 12

What are the causes of transient colonic spasm?

Answer 12

• narcotic premedications
• cold contrast medium
• irritation of the wall by the catheter

Question 13

Answer 13

meniscus sign > intussusception (in this case: ileocecocolic in a dog)

Question 14

Answer 14

dog with a pelvic fibroleiomyoma that caused partial colonic obstruction and fecal accumulation

Question 15

Answer 15

Generalized megacolon in a young dog due to Hirschsprung’s disease, which is a congenital deficiency in colonic innervation. Note the increased opacity of the fecal material due to inspissation

Question 16

Normal canine colon diameter

Answer 16

< L7 length

Question 17

Normal feline colon diameter

Answer 17

2.2x SI diameter

<1.3 L5 length
<2.8 L2 endplate

Question 18

____________ is clinically defined as infrequent and reversible fecal retention,______________ as permanent but reversible loss of colonic function, and______________ as permanent and irreversible colonic distension.

Answer 18

Constipation;
obstipation;
megacolon

Question 19

A ratio of _____ between colonic diameter and L5 length in cats, is suggestive of megacolon.

Answer 19

1.5

Question 20

Which spinal anomalies can lead to megacolon?

Answer 20

Cauda equina syndrome
Sacrocaudal agenesis in Manx cats

Question 21

Which metabolic disorders can cause megacolon?

Answer 21

hypokalemia
hypothyroidism

Question 22

What are some mechanical causes of colonic obstruction?

Answer 22

pelvic narrowing (malunion fractures)
prostatomegaly
lymphadenomegaly
colonic masses

Question 23

Answer 23

barium enema of a cat with an ileocolic intussusception. The intussusceptum creates a filling defect in the barium. Edema and swelling of the intussusceptum create a coiled-spring appearance to the filling defect; this is typical of the appearance of the intussusceptum in a barium enema.

Question 24

what do A, BL C and D represent?

Answer 24

Question 25

Answer 25

medial iliac lymphadenomegaly, secondary to anal sac adenocarcinoma in a dog

Question 26

Answer 26

prostatomegaly

Question 27

Answer 27

Question 28

images a, b, c (not bottom right)

Answer 28

dog with a colonic volvulus. The large comma-shaped or C-shaped distended bowel segment in the cranial abdomen is typical of a colon torsion. Also, the cecum (C) is located dorsally and on the left, and the transverse colon (T) is in the mid-abdomen.

Question 29

Answer 29

Barium enema in a dog with a colon torsion showing the twist in the descending colon.

Question 30

Answer 30

dog with localized colitis, characterized by nondistensibility and mucosal irregularity of the distal portion of the descending colon

Question 31

Answer 31

dog with a benign colonic stricture of unknown etiology.

Question 32

Answer 32

dog with a mass (arrows) creating a polypoid filling defect in the mid-portion of the descending colon. The diagnosis was lymphoma.

Question 33

Which segments are missing in feline short colon syndrome?

Answer 33

ascending and transverse colon; this leads to leftward displacement of the ileocolic junction.

Question 34

What does a hyperechoic band in the colonic muscular layer represent?

Answer 34

fibrous tissue of the mesenteric plexus, separating the inner circular and outer longitudinal tunica muscularis (normal finding)

Question 35

What do hypoechoic submucosal micronodules represent in canine colons and feline cecums and colons?

Answer 35

Enlarged lymphoid follicles; in the feline cecum, they can coalesce to form a follicular layer.
They can be found in asymptomatic patients, but some studies suggest it represents active inflammation or neoplasia if there is concurrent wall thickening or loss of layering.

Question 36

In the dog, to which lymph node is the white arrow pointing?

Answer 36

right colic

Question 37

Answer 37

Question 38

Answer 38

Dorsal rectal wall thickening (between arrowheads) due to submucosal bleeding in a Labrador retriever that sustained trauma.

Question 39

When measuring the colon to compare
with the length of L5 to determine
megacolon in cats with highest accuracy
(76.9% sensitivity, 84.6% specificity),
a) measure the colon at at the maximum
diameter (a)
b) measure the colon at the pelvic inlet (b)
c) measure the colon at the level below L5,
by drawing a perpendicular line (c)
d) measure

Answer 39

a) measure the colon at at the maximum
diameter (a)

Question 40

Which of the following involves a mechanical etiology of megacolon?
a) Manx syndrome
b) Hirschprung’s disease
c) Hypothyroidism
d) Key-Gaskell Syndrome
e) Pelvic fracture malunion

Answer 40

e) Pelvic fracture malunion