Equine Emergencies: Recognition and basic steps

Define an emergency

A serious, unexpected, and often dangerous situation requiring immediate action

When to expect an equine emergency?

First opinion practice, referral hospital, at a horse event

What equine emergencies effect the alimentary and liver system?

Colic (1 in 10), abdominal trauma

What are urgent equine situations that effect the alimentary and liver system?

Choking (esophageal obstruction), colic (potentially), poisons/toxins, concentrate overload

What equine emergencies effect the respiratory system?

Dyspnea, thoracic trauma

What equine emergencies effect the spleen, blood, and cardiovascular system?

Severe hemorrhage, severe wounds, guttural pouch mycosis

What equine emergencies effect the nervous system?

Trauma/fracture (esp cranial or spinal in nature)

What are urgent equine situations that effect the nervous system?

tetanus, pharyngeal paralysis, vestibular syndromes

What equine emergencies effect the special senses?

Corneal laceration

What are urgent equine situations that effect the special senses?

Closed eye, uveitis, corneal ulceration, eyelid laceration

What are urgent equine situations that effect the urinary system?

Obstruction to urine outflow, trauma to penis

What equine emergencies effect the musculoskeletal system?

Fractures and some tendon and ligament injuries, wounds (laceration or puncture), atypical myopathy

What are urgent equine situations that effect the musculoskeletal system?

Wounds (laceration or puncture), synovial contamination, foot penetration, myopathy, laminitis

What are urgent equine situations that effect the integument?

Wounds, burns

What are urgent equine situations that effect the reproductive system?

Retained placenta, foal not sucking

What equine emergencies effect the reproductive system?

Dystocia, ‘red bag’ delivery

How can you be well prepared for equine emergencies?

Support numbers on hand (colleagues/team, information/contacts, referral centers)

Facilities in house (and know who to contact for referral, transport, and disposal options)

How can you be well equipped for equine emergencies?

Check your car regularly, PPE, restraints, drugs (including sedation/analgesia), stomach tubes, gloves, lube etc, euthanasia solution

How best to prepare yourself for an emergency?

Be assertive, project confidence, have your best professional demeanor, do NOT panic.

Triage and Prioritize: Over the phone, confirm

Is this really an emergency? Gather information like hx and signalment, offer guidance whilst they wait

What advice would you offer for a colic/choke case?

Remove all food, walk in hand if safe but do NOT risk human safety

What advice would you offer for a nail in foot case?

Do not remove it, stop further trauma

What advice would you offer for a bleeding case?

Apply pressure, do not remove

Define triage

Sorting out and classification of casualties. Determine priority of need and proper palce of treatment

Triage and Prioritize: At the scene, initial assessment should include

Is this really an emergency?

Take in the whole situation, are there humans at risk?

Horses are extremely dangerous, unpredictable, and quick to panic

Clinical exam and history

Features of cardiopulmonary resuscitation in horses

Difficult due to size of patient, more practical in foals

establish Airway

Breath for patient

establish Circulation (knees in adults, use hands in foals)

Drugs that should be administered

What are possible causes of upper airway obstructions?

Severe trauma/swelling/edema of head/nasal passages

Pharyngeal obstruction, Severe laryngeal dysfunction

How can we potentially treat an upper airway obstruction?

Bypass the upper respiratory tract, emergency tracheostomy

Where should an emergency (temporary) tracheostomy be placed?

Upper third of trachea - 3rd to 5th tracheal ring

What should be done in an emergency (temporary) tracheostomy, if time allows?

Clip and surgical scrub, apply local anesthetic

What needs to be considered in an emergency (temporary) tracheostomy as you place it?

Divide muscles (sternothyrohyoideus) overlying the trachea

Stab incision through annular ligament between two rings and secure to neck

What are some causes of cardiac output/perfusion deficits?

Dehydration, Hypovolemia

How do we try to correct deficits in perfusion or cardiac output?

Fluid resuscitation (IV catheter and IV fluids)

What is the circulating blood volume of a horse?

7-8%BW

How much blood is in a 500kg horse?

35-40 L

What volume can a horse lose before it decompensates?

~30% if acute loss

What can lead to external hemorrhage in a horse?

Wounds, guttural pouch mycosis

Why should you cautiously clamp arteries in hemorrhage situations?

Neurological structures are closely associated

What can lead to internal hemorrhage in a horse?

Abdominal or thoracic injuries

What clinical signs present when significant blood loss occurs?

Depends on volume and rate of loss, tachycardia, tachypnea and hypernea indicative of hypovolemia and hypoxemia

MM color depends on severity of loss

Triage and Prioritize: Detailed assessment: what should occur during clinical exam?

Is animal viable? How are respiratory, cardiovascular, and musculoskeletal systems? Signs of exhaustion, shock, trauma, or immediately life threatening injuries? What injuries would be exacerbated by moving? Further history

How can we systematically make examination and treatment safer and easier?

Calm and logical approach, adequate restraint, consider sedation

What should we consider before attempting sedation?

Assess risks and how best to mitigate them. Change environment/handler? Other restraint? PPE? Then can consider

What should you do before a routine sedation procedure?

Clinical examination, ensure a quiet environment, choose your sedation dose and route, remember you have a duty of care to the horse, owner and farrier when administering sedation

What drug(s) do we use for sedating a horse?

A reliable, dose dependent sedative + an opioid (± an analgesia and muscle relaxant)

What sedatives are licensed in UK for horse use?

Xylazine, Detomidine, Romifidine

What is the onset of IM Xylazine?

15-20min

What is the duration of Xylazine administered IV?

20-30min

What is Xylazine recommended for?

Fractious colic, use it on its own. 

What is Xylazine not recommended for?

Routine work, short duration and expensive

What is the duration of IV administered Detomidine?

45-60min

What is the onset of IM administered Detomidine?

30min

What is Detomidine recommended for?

Routine work: Allows greater muscle relaxation, greater sedation, greater analgesia

Colic: reserve for horses with severe, unrelenting pain

What is the duration of sedation for Romifidine IV?

60-120min

What is Romifidine recommended for?

In combo with butorphanol:

Routine work: Less muscle relaxation, greater sedation required higher doses, weaker analgesia

Features of alpha2 adrenoreceptor agonists

Route of choice=IV

Onset of peak action 2-5min

"‘ceiling effect’ for intensity of sedation

Minor side effects/disadvantages of alpha2 adrenoreceptor agonists

Hyperglycemia, diuresis, sweating, decreased PCV and total protein

No food until awake, if under may suffer esophageal choke

Important side effects of alpha2 adrenoreceptor agonists

Bradycardia (care in foals), arrhythmogenicity, reduced GIT motility and secretions, upper airway obstruction, care in pyretic horses

Features of Butorphanol

Licensed use in horses: Sedation always with a2 agonist, Analgesia relatively poor

Side effects of Butorphanol use

Reduces small intestinal activity but minimal effect on pelvic flexure

Cardiovascular and respiratory depression

Routine sedation protocols: alpha-2 agonist + opioid features

common practice to mix in same syringe, dose depends on size, age, temperament, procedure, and excitement of patient

Routine sedation protocols: notes on dosages

A definite art/experience/personal preference

How can you sedate a difficult horse?

IM alpha 2 agonist, remote injection using length of tubing

Last resort= Dart gun

Acepromazine is licensed in horses via what routes?

IV, IM, or oral gel

Features of Acepromazine as a tranquilizer

Anti-anxiety, duration of 4-6 hours

What can acepromazine be used on its own for?

To calm an anxious but cooperative horse (ex for clipping)

What should acepromazine NOT be used for?

Invasive procedures/difficult horses

Why is acepromazine contraindicated in breeding stallions?

Associated with priapism and paraphimosis

In regards to musculoskeletal injuries, what should you discuss with the owner when presenting options?

Not just functional, but cosmetic repair, management at home vs clinic, costs

When should you consider referral for musculoskeletal injuries?

Extensive wounds, synovial structure involvement, fractures

What should you keep in mind when referring a horse for a musculoskeletal injury?

Talk to the referral hospital, still provide first aid and prep horse for transport

Stabilization is key, immobilize for fractures

Prophylactic antimicrobials, provide analgesia, check tetanus status

What options do we have for systemic analgesia in horses?

NSAIDS, a2 agonists, opioids, paracetamol, lidocaine infusions, ketamine, gabapentin

What condition has analgesia playing a central role in its management?

Colic

What are the classical signs of colic?

Pawing, flank watching, rolling

What systems can cause colic to present?

GIT, urogenital, liver, and spleen are all possible causes

What other things could colic present similar to?

Laminitis, peritonitis, myopathy, esophageal disease, neurological conditions, pneumonia, cardiovascular problems, pyrexia of unknown origin

How can you differentiate colic from other possible ddxs?

History and clinical exam need to work together.

Further tests include rectal exam, nasogastric intubation, blood work, abdominocentesis, US

What are the classifications of colic?

Spasmodic, impactive, flatulent, obstructive, non-strangling infarction, enteritis, idiopathic

Extra slides 55-57 See module 16

Features of nasogastric intubation

Tube passed via ventral meatus

Use twitch or sedation? Always warn the owner you might cause a nose bleed

What are diagnostic features of nasogastric tube intubation?

>2 L reflux usually implies SI obstruction

Choke is implied if tube can’t be passed into the stomach

What are therapeutic features of nasogastric tube intubation?

Short term for SI obstruction, prevents gastric rupture

Analgesic to reduce dilation of stomach

Administer fluid or medication

Choke- small volume lavage

What NSAIDS can be used for colic analgesia?

Phenylbutazone, flunixin meglumine, ketoprofen, meloxicam

What alpha 2 agonists can be used for colic analgesia?

Xylazine, detomidine, romifidine

What opioids can be used for colic analgesia?

Butorphanol, pthidine, morphine, buprenorphine

What antispasmodics can be used for colic?

Buscopan, Buscopan compositum, metimazole

What potential NSAID side effects are of note in horses?

Nephrotoxicity, right dorsal colitis

What is phenylbutazone used for?

Colic/visceral pain (not licensed, but widely used)

What is meloxicam used for?

Analgesia, COX 2> COX 1

What is ketoprofen used for?

Licensed for alleviation of visceral pain

What is Flunixin meglumine used for?

Most potent NSAID, anti-endotoxic effect, only use if definitive diagnosis or prior to referral

What do you need to know before starting treatment and a management plan?

Can you do it? Do you need additional resources? Best treatment option? Referral? Is the client on board with it?

What are important owner factors when treating horses?

Clear communication between all staff, offer options, discuss insurance, is referral an option?

What is this horse expected to do? How emotionally attached is the owner?

What should you do when preparing for euthanasia?

Take owner with you. Do not rush, seek a second opinion if needed, or consult BEVA guidelines

What are acceptable methods of euthanasia?

Somulose injection, pentobarbitone injection, free bullet (+captive bolt)

What are the criteria for humane destruction of a horse?

The decision to advise an owner to destroy a horse on humane grounds must be the responsibility of the attending veterinary surgeon. The veterinary surgeon’s primary responsibility is to ensure the welfare of the horse.

What are criteria for immediate destruction?

Obvious catastrophic injury, open fractures, gross and unstable comminuted fracture, proximal long bone fracture, axial skeleton/cranium fracture, sustained recumbency >24hrs

Equine euthanasia needs to be

communicated clearly and obtain signed consent

What should you as a vet bear in mind when euthanizing a horse?

Empathy, discuss insurance, discuss what happens with euthanasia and just after, discuss disposal and possible post mortem.

Consider location: privacy and noise, surface and hazards, extraction for disposal

What could go wrong with a euthanasia, and how do you prepare for it?

Catheter comes out, horse is still standing.

Bring spares of everything needed!