Pain Management For
Piglets During
Castration and Tail
Docking
Monique Pairis-Garcia BS, DVM, PhD, mdpairis@iastate.edu
Anna Johnson BSc, MSc, PhD, johnsona@iastate.edu
Department of Animal Science,
Iowa State University
1
Ames, IA
Objectives
• Defining pain
• How to measure pain?
• Regulatory concerns for using pain
relieving drugs in the United States
• Case Study: Drug efficacy for pain
management during castration
2
Defining Pain
Pain: “Unpleasant sensory and emotional
experience associated with actual or potential
tissue damage”1
 Pain and suffering are clinically important
conditions adversely affecting an animal’s
quality of life (short-term or long-term)
 Prevention and alleviation of animal pain and
suffering (i.e., management) are important
goals
1IASP,
2004
3
Procedures
Painful Events
Procedures
• Castration
• Tail docking
• Teeth
clipping
• Reproductive
surgery
• Repairs
Management
• Lameness
• Shoulder
ulcers
• Heal
erosions
• Fractures
• Tail/vulva bites
• Injuries
Disease
• Lameness
• Mastitis
• Farrowing
difficulties
• Respiratory
disease
• GI disease
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Procedures
Painful Events
Castration
Procedures
• Castration
• Tail docking
• Teeth
clipping
• Reproductive
surgery
• Repairs
Management
• Lameness
• Shoulder
ulcers
• Heal
erosions
• Fractures
• Tail/vulva bites
• Injuries
Disease
• Lameness
• Mastitis
• Farrowing
difficulties
• Respiratory
disease
• GI disease
Tail Docking
5
Castration
• Removal of testicles or destruction of
testicular formation2
– Prevention of unwanted breeding
– Reduced fighting and aggression
– Meat quality improvement
• Pain associated with scrotal incision,
extraction of the testes and severing of the
spermatic cords
2Petherick
, 2010
6
Mcglone, 2014
Tail Docking
• Portion of tail removed
– Prevent/Decrease tail biting
– Decrease economic loss associated with
reduction in growth performance and increased
Liat Romme Thomsen, 2013
incidence of infection
• Pain associated with
physical removal3
3Sutherland
et al, 2011
7
How to measure pain
• Physiological measures
– Hormones, Catecholamines, Immune response
• Behavioral measures
– Locomotion, postures, maintenance behaviors
• Performance measures
8
Physiological Measures
• Hormones
– ACTH (Adrenocorticotropic hormone)4
– Cortisol
• Catecholamines
– Norepinephrine/Epinephrine5 effects on:
• Heart rate
• Glucose levels
• Lactate levels
**Physiological measures can also increase due to
general arousal and handling**
4Prunier
et al, 2005; 5Hay et al 2003
9
Physiological Measures
• Immune function6
– Acute phase proteins
– Pro-inflammatory cytokines
– Antibody response
**May result in greater welfare
concerns if animal’s health is
compromised**
6Moya
et al, 2008
10
Wikipedia, 2014
Behavioral Measures
• Behavioral changes
– Locomotion and Posture7
• Head turning toward hindquarters
• Hind leg lifting
• Slow twitching tail
– Maintenance behaviors8
• Reduced feeding
• Reduced drinking
• Reduced activity
7Wemelsfeder
and van Putten, 1985; 8McGlone and Hellman, 1988
11
Vocalization
• Behavioral indicator of pain9
– Immediate vocal response
– High frequency calling
– Increased calling rate
9Xin
et al, 1989
12
Performance Measures
•
•
•
•
•
Average daily gain
Feed intake
Market weight
Carcass quality
Mortality
13
Iowa State University, 2011
Manage Pain On
Farm
Husbandry
Techniques
Pharmacological
Techniques
14
Regulatory Concerns in the U.S.
• Animal drugs intended for use in the U.S are
regulated by Food and Drug Administration (FDA)
Center for Veterinary Medicine (CVM)10
• There are no pain relieving drugs specifically
approved by FDA for use in livestock in the U.S.11
• Extra-label drug use (ELDU) is regulated under the
Animal Medicinal Drug Use Clarification Act of 1994
(AMDUCA)
10Smith
and Modric, 2013 11Coetzee, 2011
15
AMDUCA requirements
• Valid Veterinary-Client-Patient Relationship (VCPR)
• Extra-label use limited to circumstances when a
threat is posed to the health of an animal, or when
failure to treat results in suffering or death
• FDA approved animal and human drugs
• There is no approved product to address the issue
• Product administered under the direction of a
licensed veterinarian and assigned an extended
withdrawal time to avoid residues.
16
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Pharmacological
• Local Anesthetics
– Lidocaine
• General Anesthetics
–CO2 Gas
–Isoflurane
• Analgesics
–NSAIDs
18
Local anesthetics
Local
• Most commonly used pain relieving drug in
food animal medicine12
• Produces loss of sensation without loss of
consciousness by preventing and blocking
nerve impulses
– Lidocaine/Prilocaine
**Short Acting**
12Muir
et al, 1995
19
Lidocaine
• Lidocaine is commonly suggested as a drug
for pain relief during castration and tail
docking.
• Lidocaine is NOT APPROVED for veterinary
use
• Only Lidocaine approved for humans can
legally be prescribed under AMDUCA and
used in an extra-label manner
20
General Anesthetics
• Loss of feeling or sensation
• State of unconsciousness with absence of
pain sensation
• Suppresses cerebral activity
– Co2
– Isoflurane
– Sevoflurane
**Short Acting**
21
Analgesics
Non-steroidal antiinflammatory drugs (NSAIDs)
Flunixin meglumine
Meloxicam
Ketoprofen
**Longer acting but
take time to have an
effect**
22
Case Study: Pain relief for castration
23
Materials and Methods
• 141 litters
• Four male piglets/ litter
• Four treatments
– Castration alone (C)
– Castration + Meloxicam (M)
– Castration + Lidocaine (L)
– Castration + Lidocaine + Meloxicam (LM)
24
25
26
27
Production Measures
• Mean weight on castration day was not
different.
• No difference in weight gain
• 11% morbidity with no treatment effect
• 5% mortality with no treatment effect
28
Case Summary
• Lidocaine reduced pain during castration
• Meloxicam reduced pain after castration
• No treatment effects on:
– Skin temperature, weight gain, morbidity or
mortality
• Herdsmen effectively administered local
anesthesia
29
Take home points
• Pain associated with castration and tail
docking is a current welfare issue on farm
• Pain relief may be conducted using either
anesthetics, analgesics or a combination of
both
• Use of these drugs in an extra label manner is
approved under AMDUCA
• Multi-modal drug approach is most effective
for pain relief
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THANK YOU VERY MUCH FOR
YOUR ATTENTION
QUESTIONS?
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