Lecture 8

Question 1

Occurrence of pain in domestic animals?

Answer 1

◼ Accidental injury (slip)
◼ Husbandry practices (tail docking)
◼ Surgical procedures
◼ Disease

Question 2

What is pain?

Answer 2

is an unpleasant sensory or emotional experience associated with actual or potential tissue damage (first person)

Question 3

What is Nociception?

Answer 3

is the neural mechanisms that result in
pain (third person- can be observed)

Question 4

causes of Pain (‘nociception’)?

Answer 4

Causes: thermal, mechanical, chemical, sickness
◼ Deep pain- in bones, joints, tendons (arthritis)
◼ Visceral pain- in soft tissue (Hard to locate)
◼ Cutaneous pain- superficial (sharp- poked with a needle)
◼ Acute or Chronic

Question 5

What is the Process of Nociception?

Answer 5

◼ Reception- activation of pain receptors
(Aδ and C nerve fibres)
◼ Transmission- along spinal cord to sensory cortex & to reflexive motor neurons
◼ Perception- within CNS
◼ Response- (acute pain) withdraw**,
vocalize, orient

Question 6

How do you assess pain?

Answer 6

◼ In Humans: self-report- “that hurts!!”
◼ In Animals: hard to assess (prey animals are good at hiding pain so they don’t get eaten)
◼ Measure behaviour-
◼ acute response: withdrawal,
vocalization, and orientation
◼ chronic response: immobility, posture
and isolation, AKA ‘Sickness behaviour’
◼ Measure response- to analgesics, anaesthetics
◼ Measure physiology- cortisol, prostaglandins

◼ Force plate- weight bearing, lameness assessment
◼ Grimace scale

Question 7

What pain treatments are there?

Answer 7

Anaesthesia/Anaesthetics
◼ Loss of sensation/feeling
◼ Local- specific area Eg. Lidocaine
◼ General: Induction/Excitement/General
anaesthesia

Analgesia/Analgesics
◼ Loss of pain
◼ Opioids- endorphins (endogenous
morphine-like compounds)
◼ NSAIDs- non-steroidal anti-
inflammatory drugs
◼ block arachidonic acid cascade and
prostaglandin formation
◼ Analgesic, anti-pyretic, and anti-
inflammatory effects
◼ Examples: Meloxicam, Ketoprofen,
Aspirin

Sedative
◼ Reduced responsiveness- e.g. Ketamine, Azaperone (Stresnil)

Question 8

What are painful processes?

Answer 8

Cattle
◼ dehorning, castration, branding, tail-
docking
Pigs
◼ castration, teeth-clipping, tail-docking,
ear notching
Sheep
◼ castration, tail-docking, mulesing
Poultry
◼ Beak treatment, claw trimming/removal,
dubbing
Deer
◼ antler removal

Question 9

Why is Castration & dehorning in cattle done?

Answer 9

◼ Prices for unprocessed (green) calves
are much reduced
◼ Animals safer, easier to handle
◼ Younger animals are easier to process
and suffer less setback
◼ reduce aggression

◼ But, entire males grow faster! (this is a downfall)

Question 10

Disbudding in calves

Answer 10

Horn buds removed at 4-8 weeks
3 Methods:
◼ Electrical or butane iron, Caustic paste or Gouging

◼ Pain response- all methods: behavioural changes and elevated cortisol levels for ~4 hours
◼ Gouging has more rapid cortisol response than electric iron
◼ Local anaesthetic block- recommended for surgical pain, then post-op analgesia

Question 11

Dehorning in cattle

Answer 11

◼ Dehorning of mature animals affects
weight gain
◼ Dehorning on entrance to feedlot
reduced performance by 300 g/d for
first two weeks
◼ Effect on growth was significant over the 106 day feedlot period

Question 12

What are the beef codes and recommendations for dehorning cattle?

Answer 12

Beef Code Requirements:
◼ Competent personnel
◼ Disbud early (2-3 months)
◼ Since Jan 2016- use of pain control required after horn bud attachment

Beef Code Recommendations:
◼ Do not process calves at weaning time
◼ Select/breed for polled trait

Question 13

Castration in Cattle

Answer 13

◼ Physical (surgical, burdizzo, elastrator,
banding), chemical and hormonal methods
◼ Younger age: easier for producer & animal (easier to handle)
◼ Surgical castration induces higher
cortisol response than elastrator or burdizzo

Question 14

What are alternatives to castration?

Answer 14

Immuno castration
vasectomy
hormone suppressants
sexed semen

Question 15

Castration- Beef vs Dairy

Answer 15

Dairy code: pain control required at all ages
Beef code: pain control required for bulls older than 6 months

This might be do to practicality

Question 16

Why is Castration in Pigs done?

Answer 16

Main reason is boar taint- an
unpleasant smell and taste
◼ meat from boars can contain elevated
levels of skatole and androstenone

Secondary reason- reduce mounting
and aggressive behaviours

Question 17

Castration in Pigs

Answer 17

◼ Surgical and immuno-chemical
◼ Improvest (anti-GnRH vaccine)
◼ Surgical: at 2-7 days
◼ Young animals recover more quickly

Code Requirements:
◼ Local anesthetic & analgesic- required for pigs over 10 days of age
◼ As of July 1, 2016, castration performed atany age must be done with analgesics

Question 18

Beak treatment in Hens

Answer 18

Mechanical methods (hot blade)
◼ Dramatic reductions in eating, preening immediately after trimming when performed at later ages

Infrared beak-trimming
◼ Significant reduction in pain responses

Question 19

Acceptability of Painful Procedures?

Answer 19

◼ The general public is unaware of most
procedures and the use of anesthetics
◼ Alternative practices are available - sometimes reluctance to move away from
painful practices
◼ Codes of practice promote phase-in of
pain control and use of alternatives

Question 20

What is lameness?

Answer 20

A significant welfare issue-
◼ Reduced performance in broilers
◼ Improved through genetic selection
◼ Major reason for production losses and
culling in dairy cattle and sows
◼ Reduced welfare due to chronic pain

Question 21

Lameness assessment

Answer 21

Subjective and objective measures:

Gait scoring
◼ Subjective measure- observer ranking
◼ Developed for poultry, pigs and cattle
◼ Typically a 0 – 5 scale: 0= no signs, 5= the animal cannot walk

Accelerometers, Kinematics, Force plate
◼ Objective measures- device recording

Question 22

Lameness & self medication

Answer 22

Lame and non-lame broilers were given
feeds with and without analgesic (Danbury, 2000)
◼ Lame birds preferred the drug-treated feed
◼ Gait scores improved, performance increased

Conclusions:
◼ 1. Pain is present
◼ 2. Bird cognition: associated feed with painreduction: = self-medication

Question 23

Reducing lameness

Answer 23

Lameness can be reduced by:
◼ genetic selection, flooring/bedding,
exercise and nutrition

Is a major welfare issue- focus of much
research in poultry, cattle and pigs
◼ Eg. Rubber mats, hoof care, pain control

Question 24

What is Euthanasia

Answer 24

◼ Greek- Eu= ‘good’ + thanatos =‘death’
◼ Important for welfare- End suffering

Choose methods based on: human safety, animal welfare, practicality, animal age and location
◼ Gunshot or captive bolt gun
◼ Blunt force trauma- manual or device
◼ Anesthetic overdose (veterinary oversight)

Immediate confirmation of death
◼ Follow-up if needed (e.g., bleed or pithing)

Question 25

Euthanasia- oversight

Answer 25

Research and CCAC: euthanasia plan
(humane intervention point: HIP) required for all research protocols (AREB)

Packing plants and AMA audits:
◼ Effective stunning
◼ Immediate insensibility and death
◼ Zero returns to sensibility

Special circumstances- CFIA:
◼ E.g., Disease outbreaks- mass euthanasia