7 – Euthanasia

Question 1

Changing careers: most common

Answer 1

• *Off track thoroughbreds
  o May race once or make millions, but don’t race forever
  o High earning horses to breeding stock
• Working ranch horses
  o Often switched to other wester disciplines

Question 2

Off the track thoroughbreds (OTTB)

Answer 2

• Trained to run in a circle to the left
• Complete ‘re-training’ required when racing career ends
• Many new career paths
  o Hunter
  o Jumper
  o Dressage
  o Barrel racing
  o Ranch work

Question 3

How are OTTB acquired?

Answer 3

• Direct racing connection
• Resale
• Non-profit aftercare facility
• Auction/kill pen

Question 4

Reduced workload

Answer 4

• Due to age, illness, injury
• Options
  o Retirement
  o Lower level of work/performance
  o Sell (with provisions)
  o Donate
• *choice will depend on variety of factors
  o In case of injury or illness, a definitive diagnosis will help define the best decision for the horse

Question 5

Retirement plans

Answer 5

• Kid horse
• Companion animal
  o Another horse or person
• Equine therapy
• Retirement or rescue farms

Question 6

What are signs of consciousness in a horse?

Answer 6

• Vocalization
• Attempts to rise
• Lifting head
• Blinking
• Response to painful stimulus
• *reflex movements may occur

Question 7

Euthanasia

Answer 7

• Death may take several minutes to occur
• *planned or emergency
• *QUICK, MINIMAL PAIN/STRESS, IMMEDIATE UNCONSCIOUSNESS
• Often in the FALL

Question 8

What are the reasons for euthanasia?

Answer 8

• Illness
• Injury
• Age
• Behaviour/safety
• Economics

Question 9

What are some criteria that may contribute to the decision of euthanize?

Answer 9

• Cost of treatment
• *Pain and suffering: MOST common
• Return to use
• Likelihood of survival
• Length of recovery
• Insurance status
• other

Question 10

Making a decision for a sick or injured horse: some questions to consider

Answer 10

• Is it likely to recover?
• How long will it take to recover?
• What will the quality of life be?
• Can owner provide increased level of care?
• Has horse gotten better or worse through the course of treatment?

Question 11

What are the methods of euthanasia?

Answer 11

• Lethal injection (overdose of pentobarbital, KCl, MgCl)
• Intrathecal lidocaine injection
• Captive bolt
• Gun shot

Question 12

What are things to consider with an euthanasia appointment?

Answer 12

• Circumstances
• Client: present or absent
• Surroundings
• Pets, wildlife, scavengers
• Method of disposal
• *catheter placement and drug administration (sedation, general anesthesia)

Question 13

Pentobarbitol

Answer 13

• Barbiturate acting on CNS
  o Binds GABA receptors=CNS depression
  o Inhibits glutamate
  o Loss of respiration, then brain dead in 73-261s, heartbeat stops
  o ECG takes 10-15mins to go
• Controlled substance
• Toxic to scavengers

Question 14

Pentobarbitol use in horses

Answer 14

• Catheter, 2 long extension sets
• Sedate
• Dose: 70-150mg/kg
• Stand back!
• Rapid injection
• Unpredictable reflexes
• Agonal breath
• *caution in compromised horses

Question 15

KCl and magnesium salts

Answer 15

• Needs to be anesthetized prior to injection
  o NOT considered human if administered in conscious animal
• Powder dissolved in warm water and rapidly injected IV
• Not a controlled substance, NOT environmentally toxic
• KCl: cardiotoxic
• MgCl, MgSO4: suppression of neural activity

Question 16

Intrathecal lidocaine

Answer 16

• 2% lidocaine hydrocholoride administered at the atlanto-occipital space under GA
  o Direct anesthetic effect on neural structures
  o Halts brainstem function: breathing stops immediately
  o Loss of brain electrical activity, up to 226s
  o Heart stops in 10mins
• *CALM

Question 17

Lidocaine

Answer 17

• Inexpensive
• Readily available
• Drug residues in meat are NOT toxic to scavengers

Question 18

Intrathecal lidocaine ‘steps’

Answer 18

1. Anesthesize the horse
2. AO tap with 18g spinal needle or catheter stylet
3. 30-60ml of CSF removed prior to injection
   a. Reduces pressure for ease of injection
4. Administer 30-90ml 2% lidocaine

Question 19

Gunshot or captive bolt: site

Answer 19

• Just above point of intersection of lines drawn from medial canthus of eye to the middle of opposite ear

Question 20

What is an alternative method of ‘euthanasia’?

Answer 20

• Laceration to aorta via rectal palpation
  o Difficult and dangerous
  o Only performed if horse is already down

Question 21

How do you confirm death of the horse?

Answer 21

• Absence of movement
• Absence of auscultable heartbeat and pulse
• Absence of respiration
• Fixed and dilated pupil
• Lack of corneal blink reflex

Question 22

Disposal of horse

Answer 22

• Burial, landfill, rendering, cremation, chemical digestion
• *pentobarbitol: TOXIC, minimum 6 feet deep burial
• Moving the carcass: towing companies will often