Colic case planning

Question 1

Approach to a colic

In the first instance?

Answer 1

History from owner length of colicing, signs being shown and duration of signs (intermittent, continuous).

• Also management factors- feed, exercise, worming regime, any changes etc.
• Have they given anything previously (any sachets of bute etc as this may have dampened the signs you will see now)

Demeanour of the horse – quiet and non-responsive vs agitated

• N.B Ponies and donkeys are very stoical- may have a lot going on internally with very little obvious signs externally
• Check stable for droppings, has it been trashed

Level of pain- need to work out severity for yourself

Degree of abdominal distension

Sweating/ twitching/ muscle fasciculations/ attempts to lie down/ kicking/ flank watching/ pawing/ stance of the horse

Question 2

Approach to colic physical exam?

Answer 2

Physical exam …

Restraint!

• Always ensure owner/ handler is on the same side as you particularly in a colic situation as if the horse decides to go down you don’t want one person on either side- more chance of someone getting squished! Owner safety is your responsibility

Most important parameters- HR, RR and mm’s. Horse may have a murmur which may resolve once given appropriate analgesia- don’t read too much into it at this stage!

• MM’s – colour and CRT.
  
  • Normal pale pink/ red/ cyanotic?
  • CRT <2.5s (normal)/ >3s(bad Px).
• RR - normal 12-16, wouldn’t worry too much if RR was 20 but when starting to get >24/28, RR definitely increased- pain response/ pressure of abdomen against diaphragm.
• HR – normal 28 – 40. If HR >70 likely to be surgical. HR >100 v poor Px
• CV parameters are important for determining Px but also when deciding if a horse needs Sx or medical Tx.

If horse is incredibly painful need to get these markers before giving any drugs!

• If cannot examine horse any further and have these parameters can sedate using xylazine to continue physical examination
• If cannot get heart rate due to shivering/ can’t hear it- take a pulse (facial artery)

Need to do an appropriate physical exam.

• Check above eyes and legs with a quick glance for abrasions/ cuts etc. Will give you an idea if the horse has been thrashing around and colicing violently
• Checked mm’s, HR, RR already.
• Check pulse quality if haven’t used it to get a heart rate
• Temp – do before rectal, otherwise will get a false result (normal: 37.2- 38.2)
• Gut sounds- listen in all 4 quadrants. Should have 3 good propulsive sounds/ min with grumbling in between. Right dorsal quadrant- ileocaecal valve – sounds like a plug being pulled out of a drain. Approx. 1 every 30 seconds.

Question 3

What are the next steps in the approach to colic after history and physical exam?

Answer 3

Rectal examination

Ensure you have enough lube!!! Clean glove.

Methods:

• over stable door- NO! Issue that owner will be in stable whilst you are outside so if horse decides to freak out may have a safety problem. Also may break your arm!
• Around stable door – ok. Put the door against the side of the horse and stand next to it. Insert hand into rectum- this is the point they will normally object to if they are going to! Once hand inserted, evacuate rectum and fully insert arm. Can still stand to the side so the door will give some protection but can also now get in really close behind the horse and use full length of arm.
• Straw/ shavings bale behind the horse. Probably best method. If have one side of the horse against a wall will also ensure owner/ handler is in a safe position.

Question 4

Discuss rectal tears?

Answer 4

Rectal tears

• horse needs a rectal to determine what is going on
• ensure you have plenty of lube and advance slowly! If horse is staining badly stop, may want to give some buscopan compositum (butylscopolamine – anti- cholinergic so antagonises parasympathetic nervous system) to relax rectum before trying again. Don’t just ram hand in there.
• Be honest if there is a tear
• don’t try to cover it up. Perform appropriate first aid and refer it.
• Some horses are just too small to rectal

Question 5

Discuss when to nasogastric tube?

Answer 5

When to tube:

• Impaction- tube to put fluids/ electrolytes down
• Distended SI- need to tube to check for reflux and decompress the upper GI tract (>10L fluid = bad Px)
• May tube because felt impaction and get reflux- care! Don’t put fluid down if you have reflux!! Will only make the situation worse!
• Absent/ v reduced gut sounds - may have nothing on rectal findings but can only feel an arm length into abdomen.
• May also have reflux if horse has a right dorsal displacement- duodenum gets trapped against right body wall due to displacement of large colon.

Question 6

Describe method for naso gastric tubing?

Answer 6

Method:

• Measure tube- will need about 3 meters of tube!
• Ventral meatus- feed with one hand and direct with other. Care not to cut off breathing to other nostril! If not in ventral meatus- hit ethmoids = bleed!!!
• Flex neck, Check for tube in right jugular groove
• If non-compliance, twitch first, don’t jump straight to sedation. Sedation will decrease gut motility further.
• Ultimately if you have distended SI, it is more important to get a tube down and decompress the stomach.
• If you leave a horse that has an SI obstruction without tubing it- there will come a point where the stomach will rupture which will = death for the horse.

Question 7

Discuss haematology and colic?

Answer 7

Haem:

Normal: PCV (30- 45%) and TP (55-70g/L)

PCV> 55 and TP> 90 – Sx. Severe hypovolaemia.

Question 8

Discuss Peritoneal tap- abdominocentesis in colic?

Answer 8

Lowest point of abdomen- caudal to xiphisternum, may want to go slightly right of midline due to spleen sitting on LHS

• Colour and turbidity
• Cells >10*10^9 = surgical
• Protein >30g/l = surgical
• Gut contents? - rupture

Question 9

Discuss lactate and colic?

Answer 9

Lactate

• Blood or peritoneal
• Fantastic prognostic indicator – levels increased in hypovolaemia.
• Horse side tests- levels increased if left in tube so if not ran immediately may get falsely high levels
• Blood > 2.5 g/l (Sx)
• Peritoneal >2 g/l (Sx)

Question 10

Further discuss what to do?

Answer 10

Give some pain relief! How does it respond?

What pain relief?

• Flunixin (1.1 mg/ kg)
• Phenylbutazone (max 4.4 mg/ kg)

Question 11

If have L dorsal displacement (spleen will play a role, may want to give?

Answer 11

phenylephrine to shrink spleen and abdo contents might jiggle themselves back into place without surgery)

Question 12

Indications for colic surgery?

Answer 12

• Positive rectal finding
• Severe, non-responsive pain
• Progressive cardiovascular deterioration
• Positive paracentesis (protein or cells)
• Progressive reduction in motility
• Increasing, life-threatening distension

Question 13

The main aim of rectal examination should be to identify aspects that will alter the diagnostic or therapeutic approach to a case, rather than focusing a definitive diagnosis. Examples are:

Answer 13

The presence of distended small intestine on rectal examination indicating that nasogastric intubation is required

The presence of a large colon impaction indicating the need for treatment with oral fluid therapy.

Question 14

Palpation is limited to the caudal third of the abdomen, and therefore a number of conditions affecting the cranial abdomen such as:

Answer 14

• gastric impactions
• sternal flexure impactions
• some epiploic foramen entrapment cases

may have no palpable abnormalities.

Question 15

The anatomic configuration of the gastro-oesophageal junction in the horse means that gastric rupture is a significant risk in horses with proximal obstructions including:

Answer 15

• small intestinal strangulations
• grass sickness
• ileal impaction
• gastric impactions

Nasogastric intubation is therefore an essential procedure in these cases

Presence of more than 1-2 litres of fluid in an adult horse should be considered abnormal and consistent with a proximal obstruction.

Question 16

Describe the anatomical features of the SI?

Answer 16

• Small diameter (normal diameter <5cm)
• No taenial bands, no sacculations
• Normal contents are fluid +/- some gas
• Normally located in the mid abdomen

Question 17

Describe the anatomical features of the small colon?

These features are palpable.

Answer 17

• Small diameter
• Two taenial bands, sacculations present
• Normal contents are formed faecal balls
• Normally located in the mid dorsal abdomen

Question 18

Describe the anatomical features of the caecum?

These features are palpable.

Answer 18

• Large diameter
• Four taenial bands, medial band palpable running from dorsal to ventral, sacculations present
• Contents vary but are usually semi-solid
• Normally located in the right dorsal abdomen

Question 19

Describe the anatomical features of the pelvic flexure?

These features are palpable.

Answer 19

• Medium to large diameter
• One taenial band (mesenteric band), no sacculations
• Normal contents are semi-solid / solid but indentable on palpation
• Normally located in left caudal abdomen, but may extend up to and over midline in some normal horses on pasture

Question 20

Describe the anatomical features of the left dorsal colon?

Answer 20

• Large diameter
• Similar features to the pelvic flexure, with taenial bands and sacculations reappearing in the cranial abdomen.

Question 21

Describe the anatomical features of the left and right ventral colon?

Answer 21

• Large diameter
• Four taenial bands, sacculations
• Normal contents are semi-solid / solid but indentable on palpation
• Normally located on the ventral abdominal wall

Question 22

Describe the anatomical features of the right dorsal colon?

Answer 22

• Large diameter
• Three taenial bands, sacculations
• Normal contents are semi-solid / solid but indentable on palpation
• Normally located in the right dorsal abdomen, cranial and medial to the caecum.

Question 23

Describe the anatomical features of the left kidney?

These features are palpable.

Answer 23

• Smooth rounded caudal pole, palpable in most horses
• Located in the left dorsal abdomen against the dorsal body wall.

Question 24

Describe the anatomical features of the spleen?

These features are palpable.

Answer 24

• Solid soft tissue surface with no obvious protrusions or masses, pointed caudal border
• Located in the left caudal abdomen against the left abdominal wall

Question 25

Outline indications for nasogastric intubation?

Answer 25

Question 26

Look at this diagrammatic representation of the normal anatomical structures on the left side of the equine abdomen:

Answer 26

Question 27

Look at this diagrammatic representation of the normal anatomical structures on the right side of the equine abdomen:

Answer 27

Question 28

Look at this diagrammatic representation of the normal anatomical structures viewed from the caudal aspect of the equine abdomen:

Answer 28