Colic Flashcards
Clinical signs of colic (varied presentation)
Quiet
Laying down more
Inappetant
Flank watching
Pawing
Bruxism/lip curling
Rolling
Causing themselves injury
What is colic?
Presentation of abdominal pain
What can colic be associated with?
- Gastrointestinal tract
- Peritoneal cavity
- Reproductive tract
- Renal disease - relatively uncommon in horses
- Hepatic disease
- ‘False colic’
○ E.g. laminitis
And many more
Chemical restraint for colic assessment
⍺2 agonists – xylazine first choice
§ Shortest acting
§ detrimental effects on blood pressure
§ Good for the sedation to have worn off before you leave
Analgesia
§ Painful fractious animals
§ NSAIDs first choice
§ Do not be afraid of using flunixin
Wait to administer drugs until after you’ve made a clinical assessment
BUT give drugs before doing anything else if that’s what you need to do to make it safe
Nasogastric intubation technique
Restraint
○ Nose twitch
○ Sedation
Pass tube up ventral meatus to nasopharynx
○ ‘ventral and central’
Flex chin towards chest
○ Encourages swallowing and helps to avoid passing tube into trachea
Pass into proximal oesophagus then check location
Should get negative pressure if in the right place
More than 2 litres considered abnormal
Diagnostic tools for colic
Nasogastric intubation *
Rectal palpation *
Abdominocentesis
Haematology and biochemistry
Ultrasonography
Abdominocentesis
Serosanguineous appearance sensitive indicator of devitalised intestine -> surgical lesion
Compare lactate concentration to blood lactate, >16mmol/l associated with non-survival
Normal/low protein transudate (abdominocentesis)
Colourless/pale yellow
Clear
<5000 nucleated cells/uL
<2.5 g/dL protein conc by refractometry
Transudative effusion (high protein) (abdominocentesis)
Courless/pale yellow
Clear to slightly hazy
1500-10,000 nucleated cell count/uL
2.5-3.5 g/dL protein conc.
Exudative effusion (abdominocentesis)
Variable
Turbid/hazy
> 10,000 nucleated cell count/uL
> 3.0 g/dL protein concentration
Haemoatology and biochemistry
Serum lactate from peripheral tissues - correlated with survival
Can show whether it needs fluids, does it need surgery etc.
GGT often increased
Glucose often increased
Pre-renal azotaemia
Hyperlipaemia (donkeys and inappetant horses)
FLASH ultrasound scanning
Better for SI pathology
- gastric distension
- distended small intestine
- ventrum
- Gastrosplenic window
- Nephrosplenic window
- Left middle third
- Duodenal window
- RIght middle third
- Cranial ventral thorax
Spasmodic/gas colic
Most common
Not well defined
No physical abnormalities, except maybe distended intestines
responds to basic treatment (analgesia and buscopan)
Signs of spasmodic/gas colic
Increased borborygmi, systemically well, may have loose faeces (e.g. lush grass with be bright green loose droppings)
Pelvic flexure impaction
pelvic flexure is prone to developing impactions due being a tight ‘bend’ in the colon, and due to the broader, sacculated ventral colon narrowing at this bend to become narrower dorsal colon
Impacted ingesta
○ Primary
§ E.g. diet change, box rest, reduced water intake, etc
○ Secondary
§ E.g. colon displacements, altered motility for example due to grass sickness/equine dysautonomia
Risk factors for pelvic felxure impaction
Less turnout (box rest, weather etc.)
Diet change
Poor dentition
Clinical signs of pelvic flexure impaction
Mild to moderate pain
Reduced faecal output
Diagnosis of pelvic flexure impaction
Ractal palpation
- firm mass in pelvic flexure
- ventral midline/left of midline
- variation in size/consistency
- can be very large
- consitency can be very firm, or softer and indentable
Treatment of pelvic flexure impaction
Enteral fluid therapy is superior to IVFT
§ Isotonic solution superior to liquid paraffin
§ Magnesium sulphate (irritates gut lining into secreting fluid itself)
Use meaningful volumes
§ Rule of thumb: 1L/100Kg bodyweight
§ Every 2-4 hours unless contraindicated
Sometimes leave tube indwelling if in the hospital
Withhold feed
Risk factors for caecal impaction
Orthopaedic surgery, ocular disease (NSAID use – correlation isn’t necessarily causation! - seen in very painful horses rather than horses
Dentition
Tapeworm
Decreased turnout
Two types of caecal impaction
Type I: dry ingesta
Type II: underlying motility disorder, more fluid consistency
Clinical signs of caecal impaction
Reduced faecal output
Although will continue to pass faeces, so often this early warning sign is missed
Often deceptively mild colic
Often have a normal heart rate
Sometimes very subtle until point of rupture - life threatening
Diagnosis of caecal impaction
Rectal palpation (4-5 o’clock)
Treatment of caecal impaction
Type I: enteral fluid therapy, surgery if not improving (more quickly than for pelvic flexure impaction)
Type II: surgical? More likely to rupture
Prokinetics?
There isn’t a consensus!
Withhold feed
Gastric impactions
Primary
- Feed that swells in stomach
Secondary
- Motility disorders
- Liver disease
Small colon impactions
Poor quality hay, lack of exercise, parasite burden, reduced water intake,salmonella
Relatively rare
Sand enteropathy
Regional – sandy soil
Diarrhoea/weight loss, or acute colic - due to how abrasive it is
Diagnosis of sand enteropathy
Auscultation: specific, not sensitive (may sound like waves on a beach)
Sand sedimentation (faecal) test: not sensitive/specific. Do it because its free but don’t rely on it
Radiography - gold standard
Treatment of sand enteropathy
Magnesium sulphate and psyllium found to be superior to either alone
If very severe sometimes do require surgery - difficult! Colon very heavy, sand is abrasive and causes injury to the colon epithelium -> very sick
Minimise sand ingestion
Large colon displacements
Mild to moderate colic, may wax and wane
Proposed causes:
- Large concentrate meals
fermentation -> gas distension -> migration of large colon
- Altered motility
Right dorsal displacement of the large colon (RDD)
Cranial displacement of pelvic flexure towards diaphragm
Colon moves cranially - either medially or laterally to the caecum
Diagnosis of right dorsal displacement of the large colon (RDD)
Rectal
§ Gas distended colon
§ Tight taenial bands
§ Abnormal location (may be coursing laterally) or absence in normal location
Ultrasound
§ ‘turtle sign’: visualisation of colonic mesenteric vessels against right body wall
§ Mural oedema
Often have increased GGT concentration
Treatment of right dorsal displacement of the large colon (RDD)
64% reported to respond to medical treatment
Withhold feed
Fluid therapy (enterally/IV/both)
Exercise
Can progress into a colon torsion which is always critical and needs surgery
Left dorsal displacement of the large colon (LDD)
Pelvic flexure moves dorsally into the nephrosplenic space
Diagnosis of Left dorsal displacement of the large colon (LDD)
Rectal - colon in nephrosplenic space
US - large colon obscures left kindey
Treatment of Left dorsal displacement of the large colon (LDD)
76% reported to respond to medical treatment
Lunging
Phenylephrine and lunging
§ Sympathomimetic – splenic contraction
§ Contraindicated if > 15 yrs, increased risk of haemorrhage (general vessel compliance issue?)
Rolling under anaesthesia with phenylephrine superior
Equine grass sickness (EGS, equine dysautonomia)
Enteric and autonomic neuronal degeneration
○ Variation in severity/extent of neuronal damage
○ Different sub-categories of EGS (acute, subacute, chronic)
Functional obstruction - may also develop impactions secondary to this
Pathogenesis unknown
GI absorption and haematogenous spread of a putative neurotoxin
Strongly associated with grazing
Risk factors for Equine grass sickness (EGS, equine dysautonomia)
○ 2-7yrs old
○ Recent movement
○ Recent anthelmintics
○ Particular pasture
○ Disturbed pasture
○ Mechanical poo picking
○ Cool, dry weather, frost
Three presentations of Equine grass sickness (EGS, equine dysautonomia)
Acute
- Fatal (<48hrs)
- Definitively they will die
Subacute
- Fatal (<7 days)
Chronic
- Some survive
- Reports vary, approx. 40-50% fatality rate
Clinical signs of acute Equine grass sickness (EGS, equine dysautonomia)
Sometimes colic
Tachycardia (80-120bpm)
Innapetance
Patchy/generalised sweating
Muscle fasciculations
Normal to distended abdominal stance
Clinical signs of subacute Equine grass sickness (EGS, equine dysautonomia)
Sometimes colic
HR 60-80bpm
Dyspahgia
Mild rhinitis sicca
Patchy/generalised sweating
Muscle fasciculations
Normal to distended abdomen
May progress to narrow-based stance
Clinical signs of chronic Equine grass sickness (EGS, equine dysautonomia)
Usually no colic
HR: 45-60bpm
Patchy sweating
Muscle fasciculations
Tcuked up
Narrow based stance
Diagnosis of Equine grass sickness (EGS, equine dysautonomia)
Ileal biopsies
Phenylephrine eye drops
- reverse ptosis, poor sensitivity and sensitivity
Treatment of chronic Equine grass sickness (EGS, equine dysautonomia)
Select appropriate cases to treat
- Ability to swallow?
- Degree of colic?
Treatment
- Nutritional support
- Monitor hydration status
- Analgesia
- Treat secondary problems
Prognosis of chronic Equine grass sickness (EGS, equine dysautonomia)
Very, very difficult if they cannot swallow
Stop if continuous weight loss, no recovery of appetite
Post operative ileus
Common post surgery
Nasogastic reflux, distended SI, discomfort, tachycardia
Pathophysiology of post-operative ileus
Neurogenic phase - sympathetic stimulation of GI tract after moving the abdominal contents during surgery
Inflammatory phase - due to touching the GI tract, good surgical technique is key
Management of post-operative ileus
Nasogastric intubation
Early feeding - stimulate GI tract
NSAIDs
- May affect healing of anastomosis
- Deleterious effects on mucosal healing
- Analgesic
- Beneficial effects WRT systemic inflammation
- Consensus between specialists is to use flunixin – but we actually have little data, may move towards using cox 2 selective drugs
Treatment of post-operative ileus
Restrictive fluid therapy?
§ Don’t overload them
§ Monitor electrolyte status
Prokinetics
§ Lidocaine, Probably more useful as an anti-inflammatory, Beneficial to give alongside flunixin
§ Metoclopramide - works better on proximal GI tract, so better to use with something else like lidocaine
(Erythromycin, neostigmine (better for LI disease)
Peritonitis
Commonly idiopathic
Usually secondary
Reported causes of peritonitis in adult horses
Iatrogenic
Septic
Traumatic
Parasitic
Miscellaneous
Reported causes of peritonitis in foals
Meconium impaction
Ascarid impaction
Enteritis
Ulcer
Perforation
Intussusception
Ruptured bladder
Urachal abscess
Septicaemia
Abscess
Neoplasia
Clinical signs of peritonitis
Colic (50%)
Pyrexia of unknown origin (>80%)
Lethargy (80%)
Anorexia (68%)
Uveitis
Diagnostic tests for peritonitis
Often haematology/biochemistry first due to presentation
Peritoneal fluid analysis
Diagnosis of peritonitis
Abdominocentesis
- Gross appearance
□ Turbid, abnormal colour
- TNCC – increased
- Total protein – increased
- Culture
□ Often negative even in cases of septic peritonitis
- Lactate, pH, glucose – see previous lecture
Ultrasonography, rectal palpation, gastroscopy, parasite investigation…