Other conditions of the GI tract & body wall

What is choke?

Oesophageal obstruction

What is choke usually due to?

• Impacted food in oesophageal lumen

  • Prox cervical region

  • Distal cervical (thoracic inlet) region

• Occ due to ingestion of objects

• Sometimes ass. w/ extra-luminal masses/functional abnormalities of oesophagus

How is choke diagnosed?

Usually clinical signs are sudden in onset & ass. with eating

• Coughing

• Ptyalism

• Dysphagia —> food and saliva evident at the nostrils

  

• Repeated flexion & extension of neck

How should you initially manage choke?

Most episodes clear spontaneously

• Take all feed & water away until cleared

• Monitor for 30mins

• If no improvement examine

• If does resolve spontaneously provide water but wait 1-2hrs until feeding

  • start feeding with sloppy feeds / grass

  • Ask about dental hx / any evidence of quidding behaviour —> rule out dental problems

If you are called to a choke case what should you do initially?

• Hx

• Full clin exam —> palpate L cervical region

• Sedate horse (a2 agonist/ butorphanol)

  • +/- butylscopolamine

  • helps keep calm & lowers head which reduces aspiration risk

  • +/- oxytocin

• Pass nasogastric tube to confirm diag & identify level of obstruction

  • Never force tube —> perforation usually fatal

• Lavage oeseophagus (warm water, stirrup pump better than using gravity)

• Repeat until obstructed material all removed & tube can be passed into stomach

What aftercare is needed with choke?

• Decide whether to give ABs

  • Risk of inhalational pneumonia in protracted cases

• Provide water & gradually reintroduce feed over 24-48 hrs

  • sloppy feed / grass then gradually onto forage

• Owner should monitor carefully for nasal discharge/ coughing/ dullness

• Rule out underlying cause (e.g. dental)

• Endoscopy if 2+ episodes

  • rule out underlying problem e.g. stricture

What should you do if you cannot clear an obstruction in choke?

• Can repeat lavage in 4-8hrs

  • should not be left longer thsn this —> risk of inhalational pneumonia / dehyd

• Endoscopic evaluation (may be required to remove FB)

• Occ lavage under GA

• Rarely oesophageal surgery required (high risk of complications)

What can cause oesophageal tears/ perforation

Can occur following trauma, secondary to oesophageal pathology (e.g. diverticulum) or be iatrogenic (stomach tubing)

When would you suspect oesophageal tear/ perofration?

What are the further investigations & prog?

• Marked swelling and crepitus in the left cervical region

• Horses CV parameters will deteriorate rapidly

• Further investigations using endoscopy & rads (referral?)

• Prog usually hopeless / guarded

What can occur following ingestion of large quantities of grain/ conc feed in horses?

Early & aggressive tx essential

What initial info needs to be obtained from an owner regarding carb overload?

• How much & what type of feed ingested?

• When occurred?

• If other horses could have accessed this

• If there are other additives in the feed

How should you initially manage a carbohydrate overload?

• Initial clin exam —> vitals, digital pulses, evidence of colic / abdo distension, pass stomach tube to check for reflux

• Lavage gastric contents w/ warm water (within 1-2hrs of ingestion occuring) & continue until only water is retrieved

• +/- administer activated charcoal (1- 3g/kg as slurry)

• Flunixin 0.25mg/kg IV q.8hrs

• Perform cryotherapy (ice therapy) of the feet —> reduce risk of laminitis

  

How is carb overload managed in the later stages, once signs of SIRS have developed?

• Referral or intensive medical (or occ surgical) management indicated

• Prog generally poor if signs of colic / laminitis develop

What is dysphagia?

Dysphagia —> difficulty swallowing but usually expanded to incl difficulty eating

What are the three main groups of causes of dysphagia?

• Pain

• Neurogenic

• Obstructive

Offer feed to tell what cause is

What is your approach to diagnosing the cause of dysphagia?

• Obtain full hx

• Watch horse to detemine phase of problem appearing

  • oral or pharyngeal or oesophageal

• Full CE

• Neuro exam incl. cranial nerves

• Intra oral exam (do not perform in rabies endeic areas i.e. where rabies may be potential cause)

• Imaging if required (rads, endoscopy)

• Haem/ biochem

• Other lab tests (based on suspected cause)

What are the tx options for dysphagia?

Depends on underlying cause

Referral may be warranted in some cases

NSAIDS

Slurry feed / nasogastric intubation

+/- IV fluids

General nursing care & ongoing careful observation

What common traumas can you get to the head area?

• Lip laceration —> suture with good cosmetic & functional outcome using local anaesthetic nerve blocks

• Tongue injuries —> more common in working equids due to inappropriate tack / tongue twitches applied

  • Rostral section to frenulum actually not needed always

  • partial thickness lacerations → conservative management

  • full thickness lacerations → suturing required

• Mandibular fractures- not common- can look alarming

How can you fix a mandibular fracture?

• Sedate & examine to determine configuration

• Fractures of incisive plate can be treated in field

  • Sedation & nerve blocks

  • Intra-oral wiring

List some possible causes of rectal prolapse

Usually secondary to prolonged straining:

• D+

• Colic

• Heavy parasite burden

• Proctitis / mass in the rectum

• Other causes of repeated straining —> dystocia, retained foetal membranes

How do you manage rectal prolapse according to grades?

Grades I, II (less severe) & III (looks like GII but intussusception of large colon internally)

• Reduce prolapsed tissue

• Address underlying cause

Grade IV (large colon comes through rectum)

• Surgical management (poor prog)

What are the possible consequences of trauma to the abdomen?

• Rupture of abdominal viscus

• Body wall tears / rupture

• Diaphragmatic tears

• Abdominal haemorrhage

• Peritonitis

How is trauma to the abdomen assessed?

• Obtain full hx

• Perform full clin exam —> check for other traumatic injuries

• ± abdominocentesis

• Tx based on assessment of degree of trauma / repair of wounds / suspicion of internal organ damage

• Referral?

What can cause a haemoabdomen?

Secondary to abdominal trauma:

• Splenic rupture / tear

• Uterine tear (pregnant mare)

Following parturition:

• Rupture of the middle uterine artery

How do you diagnose haemabdomen?

• Painful —> can show colic signs

• Abdominocentesis useful but be careful of intro of bacteria (blood good medium for bacteria)

• U/S

• (may need to refer but transport may be contraindicated in some cases)

What can occur secondary to a body wall hernia?

Can result in colic if intestine becomes entrapped

can be difficult to repair if extensive

How does an incisional hernia differ to a body wall hernia?

• Relatively uncommon complication following colic surgery (laparotomy) —> incr risk in horses that devekop incisional infection

• Often do not cause problems —> cosmesis is an issue

• Large hernia → risk of trauma to viscera sitting within hernia

How do you treat an incisional hernia?

• Conservative tx initially

  • Prolonged box rest in some cases

  • Use of a commercial hernia belt

• Surgical repair may be required in some

  • Repair not performed until 4-6 months after initial surgery

  • Prosthetic mesh placement

What can thoracic wall injuries lead to?

Penetration of thoractic wall can cause pneumothorax & resp distress

Potential consequences —> intr-thoracic haemorrhage, pleuropneumonia

What do you need to assess when there has been a thoracic wall injury?

• Assess for respiratory distress

• Full clin exam incl thoracic auscultation

• X-ray can tell you if there is a pneumothorax

• Determine what structures affected & depth / extent of injuries

• If wound suspect has penetrated body wall, wrap cling film around —> wound management can be performed once horse stabilised