Medical treatment of colic Flashcards
What % of horses with colic signs will need surgical intervention / euthanasia?
around 9%
What are risk factors for critical cases of colic?
- Pain score
- Heart rate
- CRT
- Weak pulse
- Absence of gut sounds in 1 or more quadrants
What would your initial approach to colic be?
- HISTORY TAKING
- OBSERVATION - colic?
- CLINICAL EXAMINATION - further tests?
- ASSESSMENT - medical / surgical
- PLAN - analgesia / Tx?
What are indications for medical tx of colic?
- Mild – moderate pain
- Good response to analgesia
- HR <50 bpm
- GI motility continuing / improving
- No net reflux
- Resolving / no abdominal distension
- Normal peritoneal fluid
- Normal PCV / TP & systemic lactate
What are principles of medical tx?
- Analgesia
- +/- oral fluids
- Other specific therapies - IV fluid, phenylephrine, psyllium
What analgesia would you give horses with colic?
- NSAIDs
- Alpha 2 agonists
- Opiates
What NSAIDS can be used for analgesia and why?
- Phenylbutazone - 12hr duration, moderate potency - good first line
- Flunixin Meglumine - 12hr duration, potent analgesia, masks increase in HR with SIRS - use with CAUTION
others =
* Metimazole (Buscopan)
* Ketoprofen
* Meloxicam
What A2 agonists can be used for analgesia + why?
- Xylazine - good analgesia, short acting (30mins) - good in assessing pain of colic
- Romifidine - 2-4hr duration, IM, Useful if moderate - severe pain (combined with butorphanol)
- Detomidine - potent analgesia for 2-4hrs, (combined with butorphanol)
What Opiates can be used for analgesia + why?
- Butorphanol - combined with A2, used in moderate-severe painful cases
- Pethidine - uncommonly used
- Morphine - potent but not appropriate for colic
What is Butylscpolamine / Hyoscine?
- Smooth muscle relaxant
- 2 forms =
- Buscopan
- Buscopan compositum - combined with NSAID (metimazole)
- Indicated in spasmodic colic
- Useful when performing rectal exam
When would you give flunixin?
– When referral is not an option & horse is exhibiting moderate / severe pain (if no response seen euthanasia is appropriate)
– When an exact diagnosis is known & medical treatment is appropriate (e.g. pelvic flexure impaction)
– When the decision to refer has already been made
When would you be cautious of giving flunixin?
– Mild / moderate pain of unknown cause & where referral is an option
What are benefits of oral fluids?
- Easy and inexpensive
- 4-6 litres water (500kg horse) / electrolyes administered q.4h by nasogastric intubation
– Stimulates gastrocolic reflex - Can place an indwelling stomach tube for continuous administration of fluids
- Provides hydration provided the horse is not refluxing
- Hydrates ingesta assisting resolution of large colon impactions
When would you administer IV fluids?
– Reflux obtained on nasogastric intubation (is there a surgical lesion?)
– Severe systemic compromise & immediate systemic support needed
What are the downsides of IV fluids?
- Expensive - £350
- Does not directly hydrate ingesta – excess fluids lost by urination
- Difficult to administer and monitor safely outside clinic facilities
How would you treat spasmodic colic?
- Butylscopolamine +/- NSAID usually effective
- Mild pain + normal CV parameters
What would you see with large colon impactions? Tx?
- Mild / moderate signs of pain
- Rectal exam findings = Doughy, firm structure on LHS of caudal abdomen
- Often in stabled animals
Tx =
* Oral fluid therapy every 4 hrs
* can add magnesium sulphate as laxative - ONCE
* Analgesia - IV flunixin meglumine
* Surgery if no response to therapy
What would you get with 2ndary large colon impaction?
- Due to grass sickness
– Corrugated feel – not smooth and large ‘vacuum packed’
– usually a primary small intestinal lesion
– results of initial +/- repeat assessments indicative of need for surgical management
What are problems with caecal impactions?
- Can rupture quickly = death
- Medical / surgical management dependent on findings on clinical exam
How would you treat gastric impaction?
- Medical Tx if mild signs
- Surgery often unsuccessful
- IV fluid therapy
- Repeated gastric lavage
- +/- use of carbonated drinks - diet coke
When would you treat large intestine displacement / distention medically / surgically?
- Medical management:
– Horses CV parameters normal
– Degree of pain not severe
– Marked gaseous distention of the large colon is absent - Surgical management indicated if:
– Severe pain / marked or increasing gas distention of colon
– Deteriorating CV parameters
– Non-response to treatment
How would you treat large intestine displacement / distention medically?
- Analgesia – careful monitoring if using potent analgesia
- Light walking / trotting exercise
- Oral fluid therapy – bolus fluids as for primary large
colon impaction - Withhold feed until faeces start to be passed
How would you diagnose / treat nephrosplenic entrapment?
- Diagnosis:
– Rectal examination
– Ultrasonography = Failure to image left kidney and spleen – gas distended large colon visualised - Medical vs. surgical management depends on initial evaluation
– Medical therapy indicated if systemic status good, pain can be controlled and mild degree of gaseous distention - Phenylephrine infusion
– 3𝜇g/kg/min as infusion in 500ml / 1L sterile saline administered IV over 15 minutes
– Horse lunged for 15 mins
– Repeat rectal examination to assess if LC has repositioned itself
– *increased risk of haemorrhage in older horses (>15 y.o 64 x the risk) – owners should be made aware of this
How would you diagnose sand colic?
– Sand in the faeces
– Classic ‘seashore’ sound on auscultation
– Sand retrieved on abdominocentesis
– Ultrasonography
– Abdominal radiography
How would you treat sand colic?
- Medical / surgical management will depend on presenting signs of colic.
– Intensive medical treatment with Magnesium sulphate (1g/kg) and psyllium sulphate (1g/kg) once daily for 4 days more effective than either treatment alone
– Monitoring of clearance using radiography - Treatment mild cases / preventive management in at risk horses:
– Remove source of sand
– Provide plenty forage
– +/- psyllium added to feed intermittently
What are causes of colic in neonatal foals?
- Degree of pain is less useful to assess need for potential surgery
– Enteritis can present as severe abdominal pain - Ultrasound particularly valuable (+/- radiography occasionally indicated)
- More likely causes of colic:
– Meconium impaction
– (Ruptured bladder)
– Enteritis
– SI volvulus
– Congenital anomalies
What is seen with colic in donkeys?
- Usually present with signs of dullness – uncommon to show marked signs of colic
– Degree of pain less useful - Colonic impactions are common
– Always check for dental abnormalities
– May be due to ingestion of foreign materials in working equid populations - Rectal examination can be performed safely
What are risk factors for recurrence of colic?
– Known dental problem
– Crib-biting / windsucking behaviour
– Weaving
– Time at pasture
When would you consider euthanasia?
- Uncontrollable pain despite potent analgesia
- Severe CV compromise
– HR >90bpm
– PCV >60%
– Purple mucous membranes - Gastrointestinal rupture
– Brown / red ingesta contaminated peritoneal fluid
– Profuse sweating, sudden reduction in pain
