Equine Colic:
Ultrasonographic and Radiographic
Diagnosis
Mattie McMaster and Friends
Introduction
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In the wild,
there is no healthcare.
Colic
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ABDOMINAL PAIN
Most commonly associated
with gastrointestinal
abnormalities
Outcome:
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Resolve spontaneously
Medical treatment
Surgical treatment
Diagnostic Tools
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Patient history and
signalment
Physical exam
CBC, biochemistry and
blood-gas
Naso-gastric intubation
Rectal palpation
Abdominocentesis
ULTRASONOGRAPHY
RADIOGRAPHY
Exploratory surgery
Indications
This is a good day
to save lives…
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Obtain a more specific
diagnosis
Decide if surgical
intervention is
necessary
Estimate prognosis
Ultrasonography: Equipment
+
+
+/-
=
Preparation
Transducer
Game-face
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Low frequency
transducer
Sector transducer
Curvilinear transducer
Machine position
Scan Regions
Normal
No surgery?
Equine Abdomen
Spleen
Oh hey.
Left
Stomach
Left
Kidneys
Left
Right
Duodenum
Right
Small Intestine
Left
Large Intestine
Left
Right
That’s what
she said.
Cecum
Right
Scan Patterns
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Three patterns
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Mucous
Fluid
Gas
Evaluate
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Wall thickness
Layering
Uniformity
Luminal Contents
Peristalsis
Mmmmm,
scan patterns.
Abnormal
Through concentration,
I can raise and lower
my cholesterol at will.
Medical Colic
Brilliant diagnosis.
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Enteritis/ duodenitis
Right dorsal colitis
Verminous arteritis
Gastric distension
Gastric ulceration
Gastric SCC
Intestinal neoplasia
Abdominal abscess
Peritonitis
Enteritis/ Duodenitis
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Fluid distension of
intestinal tract with
increased peristalsis
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Developing enteritis
Wall thickened,
edematous and more
hypoechoic
Shreds of intestinal
mucosa in lumen
Figure 1
Marked fluid distension of
stomach
Duodenitis
Figure 2
Right Dorsal Colitis
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Non-steroidal antiinflammatory drug
toxicity
Thickened right dorsal
colon
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Ventral to liver in right
10th-14th intercostal
spaces
Figure 3
Gastric Distension
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Stomach is enlarged
and filled with fluid
Hyperechoic ventral
layer representing
ingesta
Hyperechoic dorsal
layer casting dirty
shadows consistent
with gas
Figure 4
Intestinal Neoplasia
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Not routinely visualized
on transcutaneous
ultrasound
Lymphosarcoma
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Within intestinal wall
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Diffuse irregular filling
Marked enlargement of
mesenteric lymph nodes
Figure 5
Abdominal Abscess
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Found:
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Ventral abdomen
Root of mesentery
Cecum
Large colon
Fluid-filled or solid
Movement of adjacent
bowel should be
examined:
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Adhesions between
adjacent intestine and
abscess
Figure 6
Peritonitis
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Ventral abdomen
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Evaluate fluid:
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6.0 to 10.0 MHz transducer
Relative quantity
Character
Evaluate:
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Abdomen, gastrointestinal
and abdominal viscera
should be scanned for
source of peritonitis
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Abdominal abscess or
devitalized bowel
Surgical Colic
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Herniation/ displacement
Nephrosplenic ligament
entrapment
Sand colic/ enterolithiasis
Intussusceptions
Large colon torsion
Strangulating small
intestinal and small colon
lesions
Small intestine masses
Impaction
Let’s have
some fun….
Herniation/ Displacement
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Abnormal position of
gastrointestinal viscera
difficult to diagnose
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Exceptions:
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Scrotum
Thoracic cavity
Umbilical hernia
Figure 9
Nephrosplenic Ligament Entrapment
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Dorsal spleen and left
kidney not visible in left
caudal abdomen
Visualize ingesta or gasfilled large bowel
Spleen ventrally
displaced
Bright hyperechoic
reflection dorsal to the
spleen from the bowel
Figure 10
Sand Colic/ Enterolithiasis
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RADIOGRAPHS
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Not often used in adult
horses
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Exceptions:
 Sand Colic
 Enteroliths
Figure 11
Enterolithiasis
Figure 12
Sand Colic
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Small, pinpoint
granular hyperechoic
echoes
Multiple acoustic
shadows
Ventral most portion of
the affected intestine
Limits peristaltic
movement
Enterolithiasis
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Enteroliths, bezoars,
fecaliths, Hasselhoffs
Oh hey..
Affected bowel in
ventral abdomen
Hyperechoic mass
casting strong
acoustic shadow
within intestine lumen
Distension of intestine Figure 13: Badness.
proximal
Intussusceptions
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Ileum and large bowel
Right side of abdomen
“Target sign”
Fibrin tags between
segments of intestine
Figure 14
Intussusceptions
Figure 15
Large Colon Torsion
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Increased wall
thickness of the large
colon
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Increased wall thickness
is diffusely hypoechoic
Badness!
Figure 16
Strangulating Small Intestinal Lesions
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Distended, fluid-filled small
intestine proximal to
strangulated portion of
small intestine
Strangulated small
intestine
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Thickened, edematous,
hypoechoic walls
Little or no peristaltic
activity
Ventral portion of abdomen
Figure 17
Small Intestinal Masses
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Within intestinal wall
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Thickened wall
Anechoic to echogenic
Carcinoids, leiomyomas,
granulomas, hematomas,
and fibrosis
Stricture secondary to
chronic colic
Intestinal obstruction
Within lumen
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Hemorrhage appears as
echogenic clots or echoic
swirling fluid
Figure 18
Impaction
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Round to oval distended
viscus
Lack visible sacculations
Wall normal to
increased thickness
Large acoustic shadows
from impacted ingesta
Distension of intestine
proximal
Little to no motility
Figure 19
Conclusion
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Early referral and
surgical intervention is
key to successful
outcome
Ultrasonography and
Radiology:



Obtain a more specific
diagnosis
Decide if surgical
intervention is
necessary
Estimate prognosis
QUESTIONS?