Equine Colic Flashcards
Taught by Dr. Erika Little
What is the #1 predisposing factor for colic in horses?
improper management
What are the most common locations for impaction in the horse?
- Pelvic flexure
- Right dorsal colon
- Transverse colon
- Small colon
- Stomach
Where are sand impactions most commonly observed in horses?
Right dorsal colon
-
Diagnosis:
- Auscultation (sounds like a beach!)
- Fecal float/sink
- Abdominocentesis - sand
Type II cecal impactions in horses are typically the result of:
cecal dysfunction
T/F: Abdominal ultrasound is a routine part of the colic exam
True
Can confirm LDD, SI distention, bowel thickening, free fluid. Excellent tool for evaluating the GI in real time
What are the 7 locations on the horse that are examined using the fast localized abdominal sonography of horses (FLASH) ultrasound technique?
-
Left side:
- 1 - Ventral abdomen
- 2 - Gastric window
- 3 - Nephrosplenic window
- 4 - Left middle 1/3 of abdomen
-
Right side:
- 5 - Duodenal window
- 6 - Right middle 1/3 of abdomen
- 7 - Cranial ventral thorax
Where is an abdominocentesis performed on a horse?
On or to the RIGHT of ventral midline & caudal to the xiphoid
Normal lactate level in peritoneal fluid of a horse should be _____
<2
Normal WBC in peritoneal fluid in an adult horse should be _____
<5,000/μL
T/F: Normal fluid on an abdominocentesis should be serosanguinous and turbid
False.
It should not be that.
What is the minimum pre-op bloodwork prior to colic surgery?
- PCV/TP
- Lactate
- CBC with differential
- Fibrinogen
- Glucose
- BUN/Creatinine
Helps assess prognosis and help determine likelihood of intra/post-op complications
What is the best overall surgical approach for colic surgery?
Ventral midline approach
- Can exteriorize 75% of GI tract
- Minimal hemorrhage, strong closure
- Unable to exteriorize stomach, duodenum. distal ileum, base of cecum, distal RDC, transverse colon, terminal small colon
Abdominal exploration in the horse should start at the __________
cecum
When exploring the abdomen in the horse, you begin at the cecum. If you follow the lateral band to the cecocolic band, you will reach the ________
Right ventral colon
When exploring the abdomen in the horse, you begin at the cecum. If you follow the dorsal band to the ileocolic fold, you will reach the ________
antimesenteric band of the ileum
The duodenum is fixed to the dorsal body wall and transverse colon by the __________ ligament
duodenocolic ligament
What is the gold standard for assessing tissue viability?
Histopathology
Not very practical though unfortunately, so we rely on gross clinical assessment, which is only ~54% accurate
This 14 year old QH gelding was normal this morning and at lunch, but was severely painful this afternoon.
Rope horse, eats grass/alfalfa mix, and pellets. Up to date on vaccines and deworming. No history of previous colic and no meds
Physical Exam: Temp: 100.8, HR: 80, RR: unable d/t pain, mm: “muddy”, CRT: 3, GI neg all quadrants. Evidence of self induced trauma over head/eyes
Based on the PE findings, what is your next step?
- Rectal exam
- Sedation/pain management
- NG tube
- Bloodwork
Sedation/pain management
Then NG tube
An owner found her 8 year old Warmblood mare violently colicky. The mare has a foal and the owner is concerned for the foal’s safety. The mare foaled 8 weeks ago and the foal is doing great (this is her 3rd foal). Current on vaccines and deworming. On spring pasture. The owner gave 10 mL Banamine PO prior to calling.
Based on this information, what is your top differential?
Colon Torsion
Other differentials include mesocolon tear, LC displacement, or other intestinal accident.
Which of the following would be a likely pre-op drug protocol for colic surgeries?
- K+ Pen
- Gentocin
- Banamine
- Tetanus toxoid
- IV Fluid (LRS)
All of the above
What structure is Justin Beiber pointing to?
Pelvic Flexure
What is the daily maintenance fluid rate for post-op colic horses?
50 mL/kg/day
Don’t forget to add losses to maintenance
After colic surgery if your patient has hypocalcemia that is refractory to therapy, this may indicate __________
hypomagnesemia
- High prevalence of hypomagnesemia post-op due to increased requirements of critically ill patients
- Can add 150mg/kg/day of MgSO4 in fluids for maintenance supplement
When supplementing potassium in a horse, it is important not to give more than ____ mEq/kg/hr
0.5 mEq/kg/hr
Usually add 80mEq to a 5L bag
When do you discontinue meds after colic surgery?
When the patient is eating, afebrile, normal CBC
What are the components of management for post-operative endotoxemia?
- FLUIDS
- Flunixin Meglumine (low dose)
-
Meds to chelate endotoxins
- Di-tri-octahedral (DTO) smectite (Biosponge)
-
Polymyxin B (binds endotoxin)
- Binds lipid A, neutralizes endotoxin
- Hyperimmune serum
- Plasma
- Heparin therapy (in cases of DIC)
What is the most common lesion in horses leading to post-operative ileus?
Strangulating SI lesion
T/F: Lidocaine CRI helps inhibit free radical production
True
For treatment of POI in horses, a Lidocaine bolus can be given to directly stimulate smooth muscle and inhibit free radical production
False
- For treatment of POI in horses, a Lidocaine CRI can be given to directly stimulate smooth muscle and inhibit free radical production.*
- DO NOT BOLUS! This can lead to muscle fasciculations, ataxia, and seizures.*
Metoclopramine stimulates smooth muscle in __________ and __________
Metoclopramine stimulates smooth muscle in stomach and small intestine
- Increases ACH release via:
- DA1 and DA2 antagonism
- 5-HT4 agonism and 5-HT3 antagonism
- Dose: 0.04mg/kg/hr CRI
-
Toxicity/Extrapyramidal effects:
- Excitement, restlessness, sweating, seizure
The most common complication from incisional infection is:
incisional hernia
Do not repair for 3 months - give time for formation of fibrous ring to so you have tissue that can hold your suture. Otherwise you will have a failed repair
Abnormal abdominocentesis along with a serum-peritoneal glucose difference >___mg/dL is indicative of peritonitis
>50 mg/dL
Abnormal abdominocentesis along with a serum-peritoneal glucose difference >50mg/dL is indicative of peritonitis
Peritoneal pH <____ with peritoneal glucose <____mg/dL is diagnostic for septic peritonitis
Peritoneal pH <7.2 with peritoneal glucose <30mg/dL is diagnostic for septic peritonitis
Age, gender, and signalment can rule in or out many differentials for colic. In newborn foals, what are your top differentials?
- Meconium impaction
- Gastric ulceration
- Enteritis
- Inguinal hernia with ruptured tunic
- Sepsis
Age, gender, and signalment can rule in or out many differentials for colic. In 2-5 day old foals, what are your top differentials?
- Ruptured bladder
- Gastric ulcers
- Enteritis
Age, gender, and signalment can rule in or out many differentials for colic. In older foals, what are your top differentials?
- Gastroduodenal ulcers
- Enteritis
- SI volvulus
- Intussusception
- Gastric outflow obstruction
- Impaction (Ascarid)
Certain breeds tend to have certain causes of colic. QH fillies often develop ________
hernias
Certain breeds tend to have certain causes of colic. TB colts tend to develop ________
ruptured bladder
Certain breeds tend to have certain causes of colic. Minis tend to develop ________
small colon obstruction
With regard to colic in foals, fillies are more predisposed to ________, whereas colts are more predisposed to ________
-
Colts:
- Meconium impaction
- Inguinal hernia
-
Fillies:
- Ruptured bladder (at urachus)
- Ureteral abnormalities
This type of grass hay has been associated with ileal impactions in the horse:
Coastal Bermuda
This procedure is performed during colic surgery for horses with surgical impactions:
pelvic flexure enterotomy
During a colic episode a NG tube is passed and positive net reflux is obtained. When this happens this treatment is often given via the NG tube:
no treatment
This lesion causes colic in horses and is often treated by jogging the horse after pharmaceutical administration:
nephrosplenic entrapment
In a colicking horse with a sand impaction, the majority of the sand is found in this specific portion of the GIT:
right dorsal colon
This is a common complication after SI surgery in the horse:
Post-op ileus
This type of colon obstruction causes severe congestion and edema in the mesentery and affected colon:
hemorrhagic strangulating obstruction
Identify this structure:
small colon
These are potential predisposing factors for colon torsion in horses:
Recent parturition, recent access to lush green grass, and recent dietary changes
It is common to see decreased levels of this mineral post-operatively due to increased requirements in critically ill patients:
magnesium
T/F: Cribbing predisposes horses to epiploic foramen entrapment
True
What major complication is associated with surgical correction of epiploic foramen entrapment (EFE)?
Portal vein tear
- Portal vein tear leading to fatal hemorrhage. Prognosis with fatal hemorrhage is not good.*
- It’s bad.*
