Colic in the horse - decision making Flashcards
What can be the actual cause of pain in colic?
Distension, inflammation/ischeamia of intestine, irritiation of peritoneum
How must obstructions be differentiated?
Mechanical versus functional
Distinguish torsion and volvulus
TORSION = twisting along long axis VOLVULUS = twisting along short axis
Reasons for non-strangulating mechanical obstruction? 2
Blood supply not affected - impaction or displacement
Reasons for strangulating mechanical obstruction?3
Blood supply compromised - volvulus, torsion, incarceration
Examples of functional obstruction/motility dysfunction
enteritis, grass sickness, post-surgical ileus
Causes of non-strangulating inflammation 4
enteritis, colitis, typhlitis, peritonitis
Examples of ischaemia-induced colic 4
volvulus, torsion, incarcaration, parasitic (s. vulgarus)
Define spasmodic colic
brief episode of pain of unknown origin that resolves with no/minimal treatment
How does impaction resolve in most cases?
Enteral/IV fluid therapy. only worst cases require surgery (aim is to soften the impaction to allow it to pass out)
How do displacements resolve?
Can resolve spontaneously but may require surgery at some point
What does infection/inflammation of the SI cause? Treatment?
Hypomotility or amotility, large amounts of nasogastric reflux. Tx = medical treatment (IV fluids)
Define typhlocolitis. treatment?
infection/inflammation of large intestine. variable amounts of diarrhoea. intensive medical treatment required
Clinical signs of peritonitis. Treatment?
Variable, often fever, depression, mild to moderate colic. Intensive medical treatment or surgery
How long does it take for a strangulating lesion to kill off a bit of intestine?
6-8 hours (absorption of toxins into blood at this point)
Describe a compromised intestine
leakage of blood and protein into abdomen, loss of fluid into intestine.
Examples of strangulating lesions in the SI 7
- volvulus (around root of mesentery),
- strangulating lipoma
- epiploic foramen impaction
- inguinal/scrotal hernia
- intussusceptions
- diaphragmatic hernia
- mesenteric rent
Examples of LI strangulating lesions - 2
Colon torsion
Intussusception (caeco-colic, ileo-caecal, caeco-caecal)
Clinical signs of a SI lesion 2
- reflux (may be absent)
- distended SI (palpable on rectal exam, visible on ultrasound)
Clinical signs - LI lesion - 4
+/- abdominal distension
- impaction or gas accumulation palpable in the LI
- displacement of LI palpable
- usually no reflux
Indications for medical treatment of SI lesions 2
Enteritis/ileus
grass sickness - diagnoses surgically by biopsy
Indications for SURGICAL treatment of SI lesions 8
- Volvulus
- strangulating lipoma
- epiploic foramen entrapment
- inguinal/scrotal hernia
- intussusceptions
- diaphragmatic hernia
- mesenteric root
- (grass sickness)
Indications for MEDICAL treatment of SI lesions 6
- spasmodic colic
- impaction
- left dorsal displacement
- right dorsal displacement
- colitis
- typhlocolitis
Indications for SURGICAL treatment of SI lesions 2
- colon torsion
- non-resolving displacements and impactions
When should you refer a colic case? 11
- slightest suscpicion of a strangulating lesion (abdominocentesis, cardiovascular compromise)
- SI lesions - reflux, palpable, visible on rectal/ultrasound - (high likelihood for surgery, medical diseases need intensive therapy)
- conditions requiring intensive medical treatment (enteritis/colitis)
- non resolving impactions (may require IV fluids or surgery = impaction+displacement)
- recurring colic/chronic colic for further work up
- if you’re not sure and the owner is willing
- moderate to severe pain
- recurrent pain
- pain poorly responsive to analgesia
- signs of CVS compromise
- severe abdominal distension
What to do BEFORE referral? 5
Discuss:
- circumstances (horse age, emotional/financial value, owner situation)
- finances (medical £1000-3000, surgical £4000-70000, colitis/enteritis £2000-5000)
- insurance (type of cover)
- expectations
- willingness to agree to abdominal surgery
Reasons for surgery in colics 4
Therapeutic and diagnostic reasons:
- suspiscion of strangulating lesion
- non-resolving displacement
- non-resolving impaction
- non-responsive or recurrent pain
Signs suggestive of medical lesion 5
- low grade pain
- still interested in feed
- no worsening over time
- lying down more than usual
- no rolling, thrashing or kicking at abdomen
Signs suggestive of SURGICAL lesion 5
- acute onset severe pain
- owner has already given one/multiple analgesic doses
- sweating, rolling, kicking at abdomen
- progressive deterioration
CVS findings - differentiate surgical and medical lesions
MEDICAL = no signs of CVS compromise SURGICAL = cardiovascular compromise (HR>48bpm, abnormal membrane colourm CRT>2sec, prolonged skin tent, delayed/no jugular filling, cold extremities and ears, poor pulse quality)
GIT findings - differentiate surgical and medical lesions
MEDICAL - no change in abdominal shape, good borborygmi, passage of normal manure, no/reduced manure for some time (impaction)
SURGICAL = distended abdomen (ask owner), no borborygmi
Other organ systems - differentiate medical and surgical lesions
MEDICAL = no other abnormalities, fever (enteritis/colitis), icteric mucous membranes (liver disease) SURGICAL = increased respiratory rate (pain, shock), abrasions or other signs of trauma from rolling, profuse sweating (pain, shock)
NGT intubation and transrectal palpation - differentiate medical and surgical lesions
MEDICAL = no reflux (2L), little haemorrhagic/black reflux (gastric rupture possible), distended SI on rectal palpation, tight gaseous distension of LI
Response to treatment - differentiate medical and surgical lesions
MEDICAL - signs of pain controlled with small dose of sedative or one dose of flunixin meglumine/buscopan, no recurrence of colic signs after initial dose, horse remains comfortable for 12-24h
SURGICAL - large dose of sedative required to examine horse, little response to flunixin meglumine, response short lived (<1-3h)
Additional diagnostics - differentiate medical and surgical lesions
MEDICAL - normal abdominocentesis (straw coloured, clear), abdominocentesis with high nucleated cell count (>100*10^9/L) and protein (>4.5-6g/L): peritonitis, normal transabdominal ultrasonographic exam
SURGICAL - abnormal abdominocentesis (haemorrhaic, orange, red, nucleated cell count >525g/L), abnormal transabominal ultrasonographic exam (distended SI, increased abdominal fluid)
List short term complications (<2-4 weeks) after colic surgery 7
- Anaesthetic complications
- post-operative colic
- post-operative ileus (reflux)
- incisional complications (infection, breakdown)
- thrombosis
- peritonitis
- laminitis
Long term complications (>2-4 weeks) after colic surgery - 2
- Recurrent/chronic colic (adhesions)
- incisional hernia
Suggest some rough prognostic guidelines - 4 types (simple medical, non-strangulating surgical, strangulating SI surgical, strangulating LI surgical)
- Simple medical colic - good (around 90%)
- Non-strangulating surgical colic - good (70-90%)
- Strangulating SI lesion - guarded (without resection 60-80%; with resection 50-70%)
- Strangulating LI lesion - guarded to poor (without resection 36-83%, resection (difficult/rarely possible) 50-80%)
