Colic - Causes and Clinical Signs

Question 1

What is colic?

Answer 1

Pain in abdomen
CS that are usually but not always
associated with a problem in the abdomen

Question 2

What are the clinical signs of colic/abdominal pain?

Answer 2

Kicking belly, flank watching, quiet/dull, rolling, lying

Hunched

Recumbent – sternal or lateral

Sweating

Question 3

What other extra-abdominal conditions may manifest similar to colic? (equine grass sickness – GI)

Answer 3

Laminitis (still, lie down, off food), myopathies (esp atypical myopathy), sweet itch, (pleural) pneumonia, pyelonephritis (kidney stones) or urinary tract problems, uterine torsion, urolithiasis, heart dx (esp tachycardias, cardiac dysrythmia))
Fracture of the leg
Cervical malformation – or seizure
Renal tumour – mild abdo pain obstructing renal outflow
Chololiths

Question 4

What types of disease may lead to visceral and parietal pain?

Answer 4

What types of disease may lead to visceral and parietal pain?
More than one of these factors may contribute towards pain e.g. strangulating lesions
Causes of pain include

• distension of regions of the GI tract which can be caused by food, gas, ingesta
• traction on the mesentery
• intestinal ischaemia
• abnormal intestinal motility e.g. spasm
• mucosal inflammation
• Twisting of the GI tract – reduced blood supply and causes pain though ischaemia

This is due to inflammation of the peritoneal lining the abdominal wall
it may be a primary problem e.g. peritonitis
or it may occur after signs of visceral pain e.g. following visceral rupture
Horses with parietal pain tend to be very reluctant to move or “board” their abdomen

Question 5

What is this?

Answer 5

Distension of SI cranial to the obstruction

Ischaemic bowel and inflammatory changes

Question 6

What is this?

Answer 6

Stomach rupture

Then pain from peritonitis

Affect peritoneal lining and serosa

Question 7

What are the causes of medical and surgical colic?

Answer 7

Medical:
Flatulent & spasmodic colic
Equine grass sickness (dysautonomia)
Colitis (e.g. grain overload, parasitism (tapeworm))
Impaction of caecum, ileum, pelvic flexure

Surgical:
SI strangulating lesions (e.g. pedunculated lipomas)
Large colonic volvulus (torsion)
Intussusception

Those that are in the grey zone where some manage medically and some surgically:
Large colon displacement (left or right)

Question 8

•What is a major body system assessment?

–Which body systems are we interested in?

Answer 8

–Cardiovascular, GIT (is it moving yes or no)

–What would you do in a CE which is not relevant in the acute case – LN, skin lung sounds.

–Listening to the GIT – Borborygmi (don’t need to refer if you can hear)

–Increased gut sounds -> gas distension

Question 9

•What parameters are useful for assessing hypovolaemia? (loss of circulating blood volume)

Answer 9

–Peripheral pulses/quality, CRT, HR, temperature of extremities, jugular fill, MM colour to an extent

–PCV, USG, Lactate, TS

Question 10

•What are useful for assessing dehydration? Difficult to assess, not easy to quantitate

Answer 10

–Tacky mm’s, sunken eyes, changes in BW

Question 11

• This MAY be important, but can be done after you have assessed the horse
• What sort of questions would you ask?

Answer 11

–Changes to horse management – suddenly turned out? Brought in?

–Past worming hx

–Hx of colic?

–Duration – but the problem is the owner may not know and make the time less.. Better to ask when you last saw the horse normal

–Any stereotypies? e.g. crib-biting and wind sucking

–When last ate/passed faeces?

–When was the horse last normal?

–Vaccinated for TETANUS (useful if going to Sx)

–age: many diseases are particular to certain age groups e.g. intussusception

–Vaccination history is IRRELEVANT unless you think it has tetanus

Question 12

What further ancillary tests are important? (4)

Answer 12

1. Lab assessment of hydration- PCV/TP/ Lactate/ blood gas
2. Palpation per rectum
3. NG intubation
4. Peritoneal tap

Question 13

What’s important in terms of our findings?

•Clinical state/degree of pain

Answer 13

–Bloating

–Abdomen guarding

–Lying down

–Rolling – abrasions etc

–Sweating

–Degree of tachycardia – the more TC the more hypovolemic and the greater the need for IV fluids

–Passed any faeces? None for a long time or very mucoid – reduced faecal transit)

–Mentation – obtunded – the more you are the less the blood to the brain

–Response to pain relief

Question 14

What’s the normal heart rate of a horse?

Answer 14

28-44

Question 15

•What does heart rate/ pulse quality tell us?

Answer 15

–Hypovolaemia

Question 16

•What does MM colour tell us?

Answer 16

–Perfusion – congestion; blood sludging and doing nothing useful. Not got good perfusion

–Hyperaemic (SIRS in this case).

–Toxic rings – haven’t quite got them in this picture.

–Rare to get to the white stage – but if you do this is decompensated hypovolaemic shock – DEATH IS COMING

Question 17

How do we grade borborygmi? What does this mean in terms of disease?

Answer 17

–Absent = 0

•Likely to be torsion or strangulation

–Reduced = 1

–Normal = 2

–Increased = 3 (can hear without stethoscope)

•Spasomodic

Question 18

•What is lactate and what is it a marker of?

Answer 18

–Produced in the cells due to anaerobic respiration. In most cases it is assign of not having enough Oxygen or ATP. Marker of hypovolaemia. 1.5-2 is normal. The most sensitive marker of hypovolaemia.

Question 19

•What is a normal PCV/TP in a horse?

Answer 19

•PCV TB: 30-45, pony: ~25-35

–Normal reference ranges are for TBs

–Shire – 25 normal (45 is huge)

–TB – PCV of 40-45 is normal

•TP: 60-80

–Ischaemia may lower to 40 but then add in hypovolaemia which will raise it to 60 - misleading

Question 20

•Why do these values increase in colic? Why can they decrease?

Answer 20

• Stress, exercise, pain – release
• Reduction in PCV and TP with GI disease – if bleeding (which is unusual but get haemhorragic disarrhoea with clostridia). May be loosing into the GIT. Reduced an then become hamoconcentrated we think the animal is okay as the PCV and TS is in normal range – false sense of security. And hence why lactate is better

Question 21

How do we place a nasogastric tube?

Answer 21

–Tube up ventral medial meatus -> pass into oesophagus (ventro-flex the neck) -> into the oesophagus check to see if in oesophagus (suck on tube – should be –ve pressure, watch the side of the neck, may hear the horse swallow). You would kill the horse if you put mineral oil into lungs. -> release of gas when enter cardia (do not breath in this gas). Create cyphon…

Question 22

•How much fluid can you recover from a normal horse via NG tube?

Answer 22

–~2L. Stomach volume is 6-8L – if theyd just drank 45 may be normal in the case

Question 23

•What findings would make you suspicious of a surgical lesion with a NG tube?

Answer 23

–Lots of fluid (>6L)

–Smell is worse than normal

Question 24

•What should the total solids from the peritoneal fluid of a normal horse be and what does it look like?

Answer 24

–TP <20g/L measured on a refractometer

–Translucent, straw coloured fluid (4 or 5 in this photo)

Question 25

•What findings are abnormal with peritoneocentesis and what did they mean?

Answer 25

–Peritonitis (6)->cloudy, very high TP. Increased cellulitis. Septic

–Ischaemia -> Serosanguinous (2) – make sure you haven’t hit the spleen. Red cell diapeddesis usually secondary to ischaemic bowel. Iatrogenic – fluid would come out straw and then red!

–Higher TP

–Green/brown – GI rupture or you have tapped the gut

Question 26

Peritoneal cytology:

• What cells predominate in normal fluid?
• What cells will increase with inflammation?
• How can you tell the difference between a ruptured viscous and a tap from the GIT

Answer 26

• Lymphocyres
• Neutrophils
• Ruptured viscous will have lots of neutrophils and intracellular bacteria

Can be seen 45 mins to an hour

Need to differentiate this!

Question 27

Rectal exam:

•What should you be able to feel?

Answer 27

–Aorta, head of caecum (RHS dorsally), caudal pole of left kidney, pelvic flexure (runs left -> right), nephrosplenic ligament, caudal end of spleen against abdominal wall, bladder (midline). Mare – uterus and 2 ovaries.

Question 28

What abnormalities would you feel on rectal palpation:

1. Strangulating SI lesion?
2. Stragulation LI lesion?
3. LI displacement?
4. PEvic flexure impaction?

Answer 28

1. Strangulating SI lesion? – intestines feel like inner tubes, fluid filled, 5cm in diameter, may see 2y PF impaction. Feel like blown up bicycle inner tubes. Normally felt on right but can be felt anywhere
2. Strangulating LI lesion? If you dare rectal. Gas distended. Taenial band.. Starts to feel like a rollercoaster going over and over
3. LI displacement – gas, abnormal location, can’t find PF (Normal: L to right in front of pelvic inlet), tension on tenial bands. Tight taneial bands.
4. Pelvic flexure impaction – enlarged flexure, easier to find, very hard consistency, can depress with thumb. Will be big.

Question 29

• Careful restraint is vital
• If no stocks then what could you consider to keep everyone safe?

Answer 29

–Sedation – alpha 2 agonist

–Twitch – neck which releases endorphins, twine on the end of the nose, ear twitch

–lifting a front leg- just make sure you trust those holding the front leg

–positioning the horse against a wall

–Using a bale is not good if you are small. If you are tall with long arms wold work well.

–Around a stable door. NOT OVER A DOOR

–IV buscopan (hyoscine, butyl something) to reduce rectal tear

–Lidocaine diluted in water to de-sensitise.

Question 30

How do you do a safe rectal exam?

Answer 30

Don’t use too much lube -> safety hazard
Gold ball amount and enter rectum in the shape of a cone. Enter centre of rectum staying ventrally. Gradually extend arm.
Rectal with short sleeves
Most kick when entering anal sphincter (will normally wag tail before)

Question 31

What should you always do aftering rectalling?

Answer 31

•Always check for rectal tears

–Look for blood on glove

Question 32

What is the cranial segment covered by?

Answer 32

•peritoneum and suspended by mesorectum

Question 33

Where do most rectal tears occur?

Answer 33

Near the pelvic inlet and involve peritoneal rectum, occur dorsally and are longitudinal

Question 34

How do you detect a tear? (2)

Answer 34

1. Pressure release over your arm feels like an unzip
2. Blood on glove

Question 35

What to do next if you have a rectal tear?

Answer 35

•Assess the severity of the tear

–bare-armed rectal

–seek help from a more senior veterinary surgeon

•Discuss the problem openly with the owner (but without accepting liability)

–You could always have the conversation before it happens

•Immediate treatment

–Sedate the horse with an A2A (NOT acetylpromazine!)

•Butylscopolamine (hyoscine; Buscopan or Buscopan Compositum)

–Lidocaine per rectum

–Epidural anaesthesia (with lidocaine or ketamine(analgesia and has some LA)) to aid examination and stop straining

• Lidocaine – short acting
• Ketamine – help get it to referral

–DO NOT GO BACK IN IF THE CAUSE WAS STRAINING

–Just the mucosa – can add vegetable oil to feed to help it pass and oral AB for 3 days

Question 36

How do you evaluate rectal tears

Answer 36

• Gently palpate rectum with bare hand circumferentially from anus cranially
• Remove faeces
• Determine- to help the management and prognosis

–Size

–Grade

–Position

Question 37

What are the 4 grades of tear?

Answer 37

•Grade 1 tears involve mucosa or mucosa and submucosa

–Heal without treatment

–ABs (e.g. TMPS), faecal softeners (e.g. liquid paraffin) and diet modification for 5-7d can help

•Grade 2 tears only disrupt the muscle layer

–Very unusual and rarely cause a problem

–Mucosa and submucosa in tact

• Grade 3a – only the serosal layer remains intact
• Grade 3b – the fat-filled mesorectum or the retroperitoneal tissues remain intact
• Bacteria leak through causing peritonitis/SIRS – can happen quite quickly
• Grade 4 tears disrupt all layers of the rectal wall

–may be grade 4 from the outset or the result of progression of a grade 3 tear

–Can feel around the peritoneal cavity with no rectum in the way

•Result in gross faecal contamination of the peritoneal cavity and rapid overwhelming SIRS and septic shock

Question 38

What first aid can you give for a rectal tear?

Answer 38

• First aid measures taken immediately have a marked influence on outcome in grade 3 and 4 tears
• Pack rectum with cotton wool retained in stockinet bandage from anus to cranial to the tear or use gamgee
• (Perstring) Suture anus closed to retain packing
• Broad spectrum bacteriocidal ABs and NSAIDs – penicillin/getamicin
• Refer to surgical facility
• If this is not an option then euthanase as they will go into septic shock and die a painful death (speak to your boss first practice may help cost)

Question 39

What additional procedures can you use for rectal tears?

Answer 39

•Abdominal ultrasonography

–Most practices have the facilities for rectal ultrasonography; probably of limited value

–Transabdominal ultrasonography more beneficial for certain conditions - e.g. Left dorsal displacement and EFE (other SI lesions). Often don’t need to know exact diagnosis – left or right will do the same thing

•Radiography

–May be useful in foals & small ponies or for sand impactions

•(Endoscopy)

Question 40

• 19 year old TB gelding
• Colicking for 2 hours
• Rolling, a little sweaty
• HR=60BPM, CRT 3 seconds, tacky MM, dark pink
• No borborygmi in any quadrant
• PCV=45% TS=80g/L Lactate=10mmol/L
• Peritoneal fluid – red with a TP of 35g/L
• Rectal exam – In the right upper quadrant you can feel multiple smooth 5cm cylindrical structures

1. Medical or surgical?
2. Likely differential?
3. What would you do?

Answer 40

1. Surgical
2. Strangulated SI lesion

–Analgesia

–Refer for Sx to unstrangulate if O funds permit

–Pass a NGT first to relieve fluid in stomach

Question 41

• 8 year old TB gelding
• Box rest for week - orthopaedic injury
• Colicking on/off for 8 hours
• Flank-watching, occasional lying down, less keen on feed
• HR=48BPM, CRT 2 seconds, pale pink MM
• Decreased borborygmi in ventral and left dorsal quadrant and normal in right upper
• PCV=40% TS=65g/L Lactate=1.4mmol/L
• Peritoneal fluid – clear and straw-coloured TP -20g/L
• Rectal exam – ventral midline –large solid structure with palpable taenial bands

1. Medical or surgical?
2. Likely differential?
3. What would you do?

Answer 41

1. Medical
2. Large colon or PF impaction
3. –Repeated bouts of enteral fluids (isotonic) to soften impaction

–NSAIDs

–Liquid paraffin is now used less as only lubes outside of faeces (doesn’t soften it)

–Also, if diagnosis is wrong and LP enters abdomen -> severe peritonitis

–If LP enters lung -> death