Lecture 39 5/2/25 Flashcards
What are the most common colic causes based on signalment?
-obese, older Arabians: strangulating lipoma
-broodmare recently foaled: large colon volvulus
-adult horse in CA eating alfalfa: enterolith
-mini horse with intermittent colic: fecalith
-foal to yearling with recent deworming: ascarid impaction
-cribber: epiploic foramen entrapment
What are the normal findings on a horse physical exam?
-heart rate less than 44 bpm
-light pink MM with CRT < 2 seconds
-no abdominal pings
-normal GI sounds in all four quadrants
-cecal contractions every 3 to 4 minutes
-no signs of pain
What are the normal findings on a horse rectal exam?
-cecum/ventral cecal band; easily moveable
-bladder
-large colon/pelvic flexure
-spleen against body wall
-open nephrogenic space
-left kidney
-small colon
-uterus and ovaries in mares
What are abnormal findings on a horse rectal exam?
-small intestine
-gas distention
-tight bands
-no large colon
-enlarged ovary
-stone in bladder
Which medications are and are not used for sedation for rectal exams?
-xylazine
-possible butorphanol
-NO detomidine; too long of sedation
What are the characteristics of buscopan?
-smooth muscle relaxation
-relaxes small intestine
-vasodilator; increases heart rate
-should do PE and obtain HR before administration
What are the characteristics of nasogastric intubation in colic horses?
-normal reflux volume is < 2L of fluid with no smell
-small reflux volume typically indicates mechanical small intestinal obstruction
-large reflux volume typically indicates enteritis
-tube should be left in when sending for referral; helps to prevent stomach rupture
Which blood tests can be done in colic horses, and what are the normal values?
-PCV: normal value of 32 to 52%
-TS: normal value of 4.6 to 6.9 g/dL
-WBC count: normal value of 5.5 to 12.5 x10^3 cells/uL
-glucose: normal value of 75 to 115 mg/dL
-lactate: normal value of < 2 mmol/L
What are the normal findings on abdominocentesis?
-glucose and lactate similar to systemic values
-WBC count < 10,000 cells/uL
-TS < 2 mg/dL
Which imaging modalities can be used in colic cases?
-ultrasound
-radiographs
Which factors contribute to the decision to do surgery on a colic?
*pain
-lasts through 3 rounds of sedation
*lactate
-abdominal lactate > double systemic lactate
- > 4 mg/dL
*septic abdomen
-abdominal glucose 50+ mg/dL LESS than systemic
-pH less than 7.3
*diagnosis/differentials
-SI distention with serosanguineous abdominal fluid
-enterolith
-septic abdomen
What are the characteristics of the ventral midline celiotomy approach to colic surgery?
-patient is under GA and in dorsal recumbency
-access to ventral abdominal contents
-best explore and access
-can still only exteriorize and visualize limited structures
What are the characteristics of the flank approach to colic surgery?
*standing sedation
*minimizes cost
*best access to dorsal abdominal contents, including:
-left dorsal displacement of large colon/nephrogenic entrapment
-small colon/rectum
-uterine torsion
What are the less commonly used approaches to colic surgery?
-ventral paramedian celiotomy
-inguinal
-parainguinal
What are the steps to colic pre-op care?
*stabilization
-hydration status
-acid/base and electrolyte imbalances
*antibiotics
-broad spectrum combo of potassium penicillin and gentamicin
*NSAIDs; banamine
*tetanus vx if 6+ months out of date
*clean/brush horse
-including picking feet out
*place NG tube
*rinse horse’s mouth
*clip abdomen within 1 hour of surgery
What are the characteristics of colic surgery recovery?
-can recover with ropes or free
-oxygen support
-continue to provide sedation until ready to extubate and stand
-can extubate early if needed
-can use leg wraps to prevent injury
What are the steps to post-op colic care?
*IV fluids
-typically twice maintenance (2L/hr)
-can supplement potassium and calcium
-regular blood work monitoring
*broad spectrum antibiotics
*NSAIDs
*hand walk
*feed ASAP; anything that can fit through tube
*possible anti-inflammatories/prokinetics
*possible anti-endotoxin medication
What are the post-op complications seen with colic?
*recurrent abdominal pain
-risk highest within 60 days post-op
-first 3 to 5 days is likely ileus
-after 7 days adhesions are likely
*ileus
-often small intestinal
-treated with anti-inflammatories and prokinetics
*septic peritonitis
-rare but serious consequence
*incisional infection
-18 times more likely to develop hernia with this complication
*endotoxemia/laminitis
-treated with anti-endotoxin medication
