Exam of the Colic Horse Flashcards
What is colic?
Abdominal pain- usually acute and usually of GI origin
Other orgins: urinary (e.g stone form bladder) or uterine torsion)
Most frequent emergency situation in horses
What is colic-like behaviour
When there is no abd pain!
Can be caused by:
- neuro e.g WNV or encephalitis or Rabies
- Skin diseases- pruritis
- Tight bandages
Aetiology/anatomy
At pelvic flexure there is 180degree turn and the diameter is also narrowing therefore prone to impactions
Stomach: is small and cranially located within the ribcage
Cannot vomit because no help from abd muscles
sharp angle btw cardia and esophagus
SI: very long and v.long mesentery but hangs from a short mesenteric root
Ventral colon: large and not fixed
Right dorsal colon: the diameter widens BUT massive decr before entering the small colon
Aetiology of colic
Change of diet
Poor quality conc
Hay
Low fibre
Decreased water
Parasites
Meterological changes- tone of NS and balance
Common features despite origin?
Pain and exhaustion
Hypovol
Endotoxaemia
These all leading to periperal circ failure!!!
- decr tissue perfusion
- haemoconc
- metabolic acidosis
- azotemia (creatinine and urea)
3 main origins of colic
Non-strangulating
Strangulating
Enteritis
Features of non-strangulating colic
Muscle spasm
Intestinal damage
Tense mesentery
These lead to:
- vasoC
- Splenic contraction
- Sweating
Features of Strangulating colic
Local circ disorder
Fluid sequestration
(necrosis?)
Colic caused by enteritis
Incr wall permeability
Dysbacteriosis
These lead to:
- release of inflamm mediators
- DIC
- Organ dysfunction
- Vessel dilation
- SIRS–MODS
Examination of the colic horse
Management is very different to other diseases (esp from chronic)
Aim of phys exam: decide if medical or surgical therapy
Usually impossible to get a definitive diagnosis- usually only see cause during surgery)
Exam must be quick, systematic and effective
Focus on CV and GIT
Important questions to ask for history
Duration of colic signs
Grade of signs: mid, moderate or severe
Frequency: continuous vs intermittent
Medication- if so if success?
Previous colic episodes
Changes in feeding or management - environment, feed, hay, concentrates
Worming
*should start the treatment then ask these questions
Physical exam: behaviour possibilities
Bright, alert and responsive
Colicky
Dull, non-responsive (bad outcome)
Rocking horse posture: usually indicates large colon infections
Dog-sitting: V. high P on diaphragm because something is distended usually
Phys exam: body surface:
Dry
Sweat patches
Profuse sweating- indicates something more severe
Other aspects of the Phys exam
Skin tent test
Skin temp- trunk, feet, ears- if cold indicates hypovolaemic shock
Rectal temp
HR:
- Normal: 28-40
- >50
- >100- indiactes rupture!!
Phys exam: resp rate and effort
Normal: 10-18
Tachypnoea, laboured breathing if something distended!
Phys exam: colour of mucus membranes
Pink: pale - dark
Brick red/dirty red
Toxic purple rim- usually around incisors
Phys exam: shape and size of abdomen
Degree of distension
Location could aid in identifying the affected part of the GIT
e.g if R side and upper- usually the caecum!
if bilat: enlarged colon
Phys exam: scrotum and inguinal area
Must be checked in stallions! could be enlarged, painful and either hot or cold
If there is an inguinal herniation- part of the SI gets into the scrotum
Phys exam: abd auscultation
Left and right paralumbar fossa (behind the last rib)
Left and right lower abdomen behind the costal arch at level of the stifle
Listen for a minimum 1 minute at each area
Sound heard behind xiphoid cart indicate sand in the large colon (moving sound, very characteristic)
Should be organised, itermittent sounds
Types of intestinal sounds
Weak: mixing of ingesta
Louder: propulsion of ingesta
At right paralumbar fossa: ileocaecal and caeco-caecal activity
Increased borborygmi indicates:
early stages of enteritis/colitis
Spasmodic colic (this is a mild type of colic)
Reduced or absent intestinal sounds indicates:
Impaction
Obstruction
Hypoperfusion
Ileus
Prep for rectal palpation
Restraint: stocks, twitch, picking up a FL, sedation (xylazine and butorphanol)
Lubrication
Buscopan: spasmolytic! relaxes the rectum and reduces the risk of tearing the rectum
Enema: if large amount of hard/dry content
Aim of rectal palpation
Diagnosis?
Distension and displacement- to identify the location
Rectal palpation technique
Remember only 30-40% of cavity is palpable!
Not possible to move hand from spine to ventral abdomen if there is gas acc due to colic
Right kindey is more cranial therefore not palpable!
Palpable structures in normal horses
Rectal mucosa
Bony pelvis
Internal inguinal rings
Cervic, uterus and ovaries
Urinary baldder
Small colon: has wide and thick antimesent, taenia will contain faecal balls
Abdominal aorta- in the midline
Left kidney: caud pole
Spleen: caud part, along the L body wall
Nephrosplenic ligament and space
Left dorsal and ventral colon and pelvic flexure
Cranial mesenteric root
Right dorsal colon
Base of caecum with ventral and medial taeniae
Peritoneum
(Small intestines)- if you can palpate it means they are distended
US
FLASH: Fast localised abdominal sonography of horses takes an average of 10.7 minutes
Whata re the 7 US windows
- Ventr abd (check for fluid acc)
- Gastric window: 10th ICS
- Nephrospleic window: on L, behind last rib, last2 ICS dosrally
- Left middle part of the abdomen- SI
- Duodenal window- R, caudodors
- Right middle third of abdomen
- Cranial ventral thorax
What does visualisation of mesenteric vessels in US indicate
Right dorsal displacement of large colon or
180degree volvolus (this is on L side)
Sensitivity: 67.7%
Specificity: 97.9%
In an US, what is between the R dorsal colon and the R liver lobe?
The duodenum- there should be no liquid content.
If distended more than 5cm= abnormal
What is a useful method of detecting sand in the abdomen?
Put faeces in a latex glove and it shoyld sink to the bottom of the glove
Technique for nasogastric tubing
Lubricate
Go through the ventral nasal meatus
Flex head
Check swallow reflex
Tube should be visible in the jugular groove
Create a siphon: can aspirate and release content from the stomach
Normal findings of nasogastric tubing
<0.5L liquid but can get up to 2L
pH should be a max of 5
When is reflux seen when doing nasogstric tubing
Spontaneous release of gs and fluid
When pH is greater or equal to 8
The small intestinal content is flowing backwards into the stomach
Prep for abdominocentesis
Wall, stocks
Twitch, sedation
Clip either side of the linea alba
Prep as for surgery!
Abdominocentesis: Needle technique
18-19G needle (spinal?)
Use left side (or midline)
Don’t use R becaue could puncture head of the caecum
Rotate and move needle if necessary
AbdominocentesisL teat cannula method
23-25G needle (end is completely blunt)
1-2ml of local anaesthetic
Blade 11 or 15 to make short stab incision
Sterile swab
Rotate and move needle
With sample:
- EDTA: nucleated cell count and cytology
- Plain: TP, lactate and glucose which are NB if we suspect peritonitis
- Cytospin- cytology
Normal findings of abdominocentesis
Usually only a small amount
Pale/straw yellow colour
Should be clear- newspaper test
TP:<25 g/L
Total nucleated cell count: non-degen Ne> mononuclear cells> lymphocytes
Should be no RBC’s
What colour is sample from abdominocentesis a few hours after strangulation
Bright red
What colour is sample from abdominocentesis after GIT rupture
Very dark red
May contain some plant material
Blood and Peritoneal fluid lactate
Increased lactate: hypovol means decr O2 delivery to the periphery- inadequate O2 utilisation (SIRS)
Lactate usually indicates strangulation if >4.4 mmol/L and rises despite fluid therapy
Normal lactate is <1.8mmol/L
