Diagnostic techniques of equine GIT (Maxwell) Flashcards
Signs of colic in foals
- foal laying on their back “showing their belly”
- non-productive straining
- reluctance to stand and suckle
colic etiologies in young horses
- ascarid impaction in SI (often post deworming)
- FB
- ileocecal intussusception (associated with nearby rivers or ponds)
colic etiologies in stallions
testicular torsion; inguinal hernia –> entrapped piece of bowel in scrotum
colic etiologies in post-partum mare
colon torsion (usually post foaling)
colic etiologies in fat middle/old-aged horses
strangulating lipoma
colic etiologies in older horses
epiploic foramen entrapment due to hepatic fibrosis & shrinkage
colic etiologies in foals
- meconium impaction
- SI volvulus
“meconium” = newborn’s first poop
colic etiologies in a horse with traumatic injury on the LEFT side
hemo-abdomen due to splenic trauma
Signs of endotoxemia (gram negative infection)
- peripheral perfusion (muddy or purple-looking mm.)
- prolonged CRT
- muzzle cold, ears cold, periphery of limbs cooler to the touch
- horse = clammy (assess skin tent)
Measuring lactate to determine perfusion relationship
Tissue hypoxia (due to poor perfusion) causes O2 delivery to exceed demand –> body switches to anaerobic glycolysis for ATP, where lactic acid is a by-product
What parts of GIT can you auscultate on right side of horse’s body?
Large colon & cecum
What parts of GIT can you ausculate on left side of horse’s body?
Large colon with SI sitting on top
Where can sand impaction occur in the horse’s GIT?
ventral part of GIT –> sand impaction in sternal flexure
Additional diagnostics that can be performed to determine colic & severity (5)
- Pass NG tube and look for reflux
- Perform a rectal exam
- BW (CBC/Chem, lactate)
- Abdominocentesis
- Abdominal U/S
How much volume obtained when refluxing a horse’s NG tube is normal, slightly more than normal, and abnormal?
Normal = < 2L
Slightly High = 2-4L
Abnormal = more than 4L
- do not administer PO meds
- consider leaving NG tube in & refluxing (aspirating) q2h
stomach volume is ~14-16L
What is the only true flexure in the equine GIT?
Pelvic flexure
sternal & diaph. flexures will straighten out if you take out intestines
Things you may assess on rectal examination of a horse (7)
- position
- motility
- evidence of distension (gas, ingesta, GB)
- bowel wall thickness
- abdominal effusion
- presence of fibrin on serosal wall (feels like grit)
- mass associated w/ abd viscera or LN
Risk of rectal exam
rectal tear (can be a life-threatening complication)
Minimum data base on a horse with suspected colic (4)
Hx, PE, palpation of abdominal viscera (rectal exam), NG intubation and reflux
Bloodwork tests and findings for horse with suspected colic
- Leukopenia (due to neutropenia [marginate/stick to wall of vessels] with immature neutrophils//bands)
- PLE (TP shows hypoproteinemia)
- Lactate (increased)
Where to tap for abdominocentesis
Low point behind the sternum, off midline, to the right (avoids the spleen)
sterile prep
Use of abdominal u/s to assess GI disease in a horse
- nephrosplenic entrapment (none if spleen and LK are touching as normal)
- evaluate gut wall thickness, GI motility and any ascites
Gastroscopy: the 5 steps
- Fast for 12h and remove water 4h before
- Alpha-2 agonist for sedation
- Pass 3-meter endoscope tube (just like NG tube) and then inflate once in stomach
- Examine stomach curvatures, margo plicatus, pylorus, proximal duodenum
- Deflate stomach w/ active suction
e.g. sedation protocol: tomidine + butorphanol
What drug is often administered for pain relief to treat colic in horses?
Flunixin meglumine (Banamine®)
NSAID & COX inhibitor
