Lecture Equine GI 1-2 Flashcards
Most equine obstructions occur
in the proximal esophagus
Esophageal obstuction
CS
- Distress
- Head extension
- Salivation
-
Nasal d/c
- food
- saliva
- milk
- Lethargy, dehydration
- +/- abnormal lung sounds
Esophageal obstuction
DX
- HX and CS: head neck extension/nose d/c
- esophageal palpation
- Resistance to NG tube
- additional
- endoscopy
- radiography
Esophageal obstuction
Resolution
-
SEDATE
- xylazine
- detomidine
- butorphanol
- gentle passage stomach tube
- wash gently with warm water
- esophageal relaxation
- buscopan
Esophageal obstuction
Management
- analgesia
- slow return to normal diet
- water, gruel
- exclude causes
- dental exam
- scope for repeated episodes
-
If they had food in naries
- broad spectrum abx to prevent pneumonia
Basic mechanisms of GI pain
- distension of a viscus
- traction on mesentary
- ischemia
- inflammation
Questions regarding colic workup
- Can pain be controlled?
- Is problem small or large intestine?
- rectal exam
- US
- Strangulating or non-strangulating?
- pain
- US
- abdominocentesis
- Is sx likely indicated?
- No? - DON’T do abdominocentesis
- Prognosis?
- Is immediate euthanasia indicated?
- has the horse already ruptured
Most common types of colic
- Large intestinal non-strangulating
- gas/spasmodic
- large colon impaction
- 80-85% resolve in field with one treatment
Colic
Subtle CS
- anorexia
- lying down more than usual
- decreased fecal production
Mod signs colic
- pawing
- stretching
- flank watching
- abdominal distention
Severe signs colic
- Rolling
- Thrashing
- Becoming cast
- facial abrasions
NG intubation
- tube every moderate to severe colic (LIFE-SAVING)
- > 2-3 liters net reflux is significant
- If > 5 liters net reflux consider leaving tube in
Initial colic
- analgesic therapy
- gastric decompression
- drugs
- fluid therapy
Management of dehydration
- Maintenance: 40-50 mL/kg/day (may be less if anorexic)
- Assess hydration status
- Calculate deficits
- Consider metabolic status
- Electrolyte abnormalities
- Enteral or IV fluids
EGUS
Risk factors
- Diet (alfalfa: protective)
- Exercise - Any
- Environment
- NSAIDS
- Foals
Gastroduodenal ulcer disease
(GDUD)
- Foals < 6 mo
- outflow obstruction
- CS
- drooling
- lethargy
- distended stomach
- Diagnostic imaging
- rads
- contrast
- US
- Prognosis: fair to good, expensive sx usually required
Non-strangulating causes of colic
- Intraluminal obstructions
- gastric impactions - rare
- ileal impaction
- cecal impaction
- large (ascending) colon impaction
- small colon impaction
- Large colon displacements
- Gas/spasmodic colic
Ileal impaction
Causes
CS
TX
- Causes
- Coastal bermuda hay
- tapeworms (live at ileocecal junction)
- Clinical signs
- Distended small intestine (SI is 90 feet long)
- TX
- GI decompression
- Remove feed/water
- analgesics, IV fluids
- deworm for tapeworms
- good to excellent prog: usually resolve w/in 24 hours
*can do an ab tap to rule out strangulating lesion
Cecal impaction
Risk factors
DX
TX
Prognosis
- Risk factors
- Broodmares near parturition
- recent general anesthesia
- Diagnosis
- rectal dx
- little evident pain possible
- TX
- rupture common
- sx often required
- gaurded prognosis
*not very common, and a severe condition
Large Colon impaction
Cause
DX
TX
Prognosis
- VERY COMMON
- Cause
- feed or sand
- occurs at pelvic flexure
- inadequate water intake, poor teeth, poor quality roughage, pain elsewhere, parasites
- Diagnosis
- Rectal
- TX
- medical therapy, red feed, fluids (enteral), laxatives
- SX for severe cases
- prognosis good
Small colon impaction
- CS
- Colic, abdominal distention, low vol. diarrhea
- often in winter
- Diagnosis
- rectal exam dx: friable
- Treatment
- medical management
- rare, good prognosis
Enteroliths
Risk factors
DX
TX
Prevention
- Magnesium ammonium phosphate
- Risk Factors
- arabians
- diet high in protein, Mg
- high colonic luminal pH
- common in CA
- DX: radiographs, palpation
- TX: surgical removal
- Prevention
- restrict alfalfa
Large Colon Displacement
Left dorsal displacement
DX
TX
- nephrosplenic entrapment
- DX
- rectal dx
- U/S: if you see bowel on left side
- TX
- phenylephrine (decreases splenic volume), and exercise < 6 yo
- Rolling under general anesthesia
- surgical correction
Large Colon displacement
Right dorsal displacement
- Difficult to DX
- Rectal exam
- fluid therapy, limited exercise, sx correction
Strangulating obstructions
In a nutshell
- all require surgery
- acute, severe pain: distention and mesenteric traction
- very sick
- sig. tachycardia > 80bpm
- toxemia
- reflux
- dehydration
- rectal
- distended SI
- small, thickened
- relatively uncommon
- serosanguinous ab tab
Choke
Causes
- Hay, pellets or cubes
- Beet pump if not moistened
- foreign bodies (apples, potatoes)
- Rapid consumption
Choke
Complications
- Recurrent laryngeal nerve damage: Roaring
- Strictures
- Esophageal rupture is terminal
- Limit treatment attempt to 30 minutes
Recurring esophageal obstruction
Scope and look for esophageal neoplasia
Characteristics of pain
- Duration
- Persistence
- Severity
- Response to analgesics
- Breed/ind variability
- Severe pain replaced by depression: Major concern
Physical exam
- Take a HR before sedating the horse
- Take a temp before recal exam
- introducing air affects temp
- MM
- toxic line
- Purple: bad
- Extremities
- if bottom of limbs are cool
- Gut sounds
Buscopan will Decrease
Gut sounds
Rectal Palpation
Basic question
- Sedation good
- Basic questions
- Distention
- SI or LI
- Gas, fluid, feed
- Masses
Abdominocentesis
Interpretation
- Lactate compared to plasma
- > 2X typical of strangulation
- Cytology
- blood or hemorrhage
- normal protein < 2 g/dL
- Normal fluid does not rule out strangulation
*Used to differentiate between SI strangulating and non-strangulating
*Strangulating: serosanguinous
Analgesics/Sedatives
- NSAIDS
- alpha-2s
- Opioids
- Buscopan
Banamine/Flunixin
Most common NSAID for visceral pain in horse
alpha -2s
- Xylazine: cheap
- Detomidine: longer acting
Opiods in horses
- Butorphanol: not very long acting
Buscopan
- anticholinergic
- antispasmodic
- short duration of action: 20 minutes
- causes tachycardia
*buscopan contraindicated when something is already VERY tachycardic
Anticholinergics
- Block acetylcholine
- inhibits parasympathetic stuff
Fluid therapy options
Enteral
- 6-8L Q 2-6 unless there is reflux (>2-3L) or small intestinal distention
Fluid therapy options
IV
- If there is
- reflux
- severe pain
- substantial dehydration
Laxatives
- Psyllium: sand
- Mineral oil
- MgSO4
EGUS
CS
- Colic after a grain meal
- Decreased performance
Only approved TX for gastric ulceration
- Omeprazole (Gastroguard)
- PPI
- TX: 4mg/kg q24
- preventative: 1-2 mg/kg q24
H-2 antagonist
- Famotidine
- Ranitidine
*cheaper, less effective
SI strangulation
Prognosis
- Survival to d/c 80-85%
- Poor to grave if > 50% SI affected
SI strangulation
Possible lesions
- Volvulus
- Incarceration
- Epiploic foramen
- Inguinal hernia
- Umbilical hernia
- Mesenteric rent
- Intestinal adhesions
- Intussusception
- Pedunculated lipoma
Large Colon Volvulus
CS
Rectal
TX
Prognosis
- Typically in broodmares 30 days post-foaling
- acute severe colic
- CS
- tachycardic
- toxic
- Rectal
- Severe LC gas distention
- TX
- SX to resolve, not resect, usually
- Prognosis
- gaurded to good if caught w/in 2 hours
*Do a physical, rectal, and sent to SX immediately, no ab tap, no passing go
