Diagnostic Techniques of Equine Abdominal Cavity Flashcards
what is ultrasonography best for (7)
- small intestinal abnormalities
- imaging the liver/spleen/kidneys
- gastric distention
- left dorsal displacement
- colitis
- large colon volvulus
- right dorsal displacements
how should you assess the full abdomen (where do you start and what direction)
start caudally on the right and work cranially assessing each ICS
repeat on the left side
ventral abdomen
what is the targeted emergency assessment using US (5)
- inguinal left and right (less hair)
- left flank (nephrosplenic space)
- gastric window (left)
- duodenal window (right)
- ventral
where is the small intestine mostly found on US
inguinal area
but can be anywhere
what should you assess when looking at small intestines (3)
- motility
- distention
- wall thickness
what should the width of the small intestine lumen be on US
<4cm is normal
>4cm is distended
how thick should the small intestine wall be on US
<4mm is normal
>4mm is abnormal
what can be seen here

multiple loops of dilated small intestine
>4cm diameter
no motility
contents separates
what are mechanical obstructions of the small intestine
- simple luminal obstructions
- strangulating obstructions
what are functional obstructions of the small intestine
- enteritis
- ileus
where is the duodenal window
right side
14th-15th ICS in the dorsal/middle third
from cranial pole of right kidney tracking cranioventrally beneath liver

what would a normal duodenum window look like
non distended
motile
what should the wall thickness of the duodenum be
<4mm
>4mm distended
what should the duodenum lumen width be
<4cm
>4cm distended
what is shown here

liver
duodenum
right dorsal colon

where is the gastric window
left side
8-12th ICS in middle third
where can you find the stomach
the gastric window
seen in 4 ICS
how do you assess distention of the stomach on US (2)
- how far back/how many ICS –> does it go back to the 14th or 15th ICS
- height of the stomach
what is seen here

stomach

where can you find the nephrospenic space
splenorenal window
where is the splenorenal window
left, dorsal behind last rib or 17th ICS
what is the normal appearance of the kidney and spleen on US
kidney should be deep to spleen
what would be abnormal in the splenorenal window
colon obscures kidney –> may displace the spleen ventrally
left dorsal displacement (nephrosplenic entrapement)
what is shown here

spleen and the left kidney

what breed of horses are more predisposed to nephrosplenic entrapment
warmbloods
large breed horses

will abdominocentesis be normal with a nephrosplenic entrapment
yes
would can you feel on rectal with a nephrosplenic entrapment
medial displacement of spleen, cannot palpate kidney
where is the colon on US
seen variably throughout abdomen
RDC deep to the liver
what is the normal wall thickness of the colon
<4mm
what would an increased thickness of the colon wall be due to (2)
- colitis
- volvulus
what would blood vessels seen on the colon indicate
displacement or volvulus
what is seen here

colitis
ventral colon
1.7cm thick
should be less than 4mm
what would be seen with volvulus of the colon (3)
- thick colon wall
- abnormal sacculations
- abnormal blood vessels
what would be seen with a right dorsal displacement on US
abnormal blood vessels tracking along right abdomen
what would be seen with a right dorsal displacement with rectal palpation
tight bands horizontally across the abdomen
what is a normal PCV range
30-40%
what does the PCV increase with
dehydration
what does the PCV decrease with
anemia
what is a normal protein range
55-70 g/L
when does total protein increase
dehydration
when does total protein decrease (2)
colitis
peritonitis
what should lactate levels be less than
<2mmol/L
what is lactate a product of
anaerobic metabolism
what does lactate increase with (6)
- hypoxia
- anemia
- dehydration
- obstruction of blood supply (strangulating lesion)
- bacterial production
- other
what does an increased lactate indicate in regards to prognosis
poor prognosis as lactate increases
what does a neutropenia indicate
colitis (salmonella!)
what does increased creatine indicate
dehydration or renal injury
why would Na, Cl, bicarb and K be decreased
loss in diarrhea or reflux
K with inappetance
why would there be an increase in bilirubin
inappetance
why would liver parameters be elevated
bile obstruction
RDD
distention of duodenum
what is the earliest indicator of strangulating lesion
abdominocentesis
what are the risks with performing an abdominocentesis
- enterocentesis
- peritonitis
how is abdominocentesis performed (5)
- US used to identify site (or just right of midline at lowest point of abdomen)
- aseptic prep of site
- insertion of 18g needle
- or local anesthesia, stab incision and teat cannula
- sample collected in plain tube and EDTA
what should normal peritoneal fluid look like
- clear
- colourless or light yellow
what should the total protein be of peritoneal fluid
<20 g/L
what should the WBC count of peritoneal fluid be
< 5 x 10^9/L
what should the lactate level be of peritoneal fluid
<2mmol/L
how do strangulating lesions result in serosanginous peritoneal fluid
- hemorrhagic infarction and inflammation
- increased capillary permeability
- movement of protein, then red blood cells, then white blood cells into abdominal cavity
what does strangulating lesion peritoneal fluid look like
red, serosanginous, turbid appearance
if lactate is higher in the abdominal fluid than the blood what does this indicate
that the lactate is coming from the abdomen
if lactate is 2x blood lactate what does this indicate
strangulating lesion is highly likely
what does peritoneal glucose decrease with
septic peritonitis
bacterial consumption of glucose
will also see increased protein and WBC
what are strangulating lesions of the small intestine (6)
- pedunculated strangulating lipoma
- epiploic foramen entrapment
- mesenteric rent
- small intestinal volvulus
- intussusception
- inguinal hernia
what are strangulating lesions of the colon
large colon volvulus
what are strangulating lesions of the cecum
cecal torsion
what are small intestine non strangulating lesions (3)
- ascarid impaction
- ileal impaction
- anterior enteritis (proximal enteritis, duodenitis-proximal jejunitis)
what are non strangulating lesions of the colon (6)
- left dorsal displacement/right dorsal displacement
- impaction
- colitis
- large colon typmany, gas colic, spasmodic colic
- pelvic flexure impaction
- enterolithiasis
what should you assess cytology of peritoneal sample (3)
- number of WBC
- presence of bacteria
- presence of feed material
what is shown here

bacteria in peritoneal fluid
what is shown here

feed material
perforation/rupture
what can be diagnosed on radiograph of the abdomen (3)
- meconium impaction in foals
- enteroliths
- sand impaction