Pain Management For Piglets During Castration and Tail Docking Monique Pairis-Garcia BS, DVM, PhD, Anna Johnson BSc, MSc, PhD, Department of Animal Science, Iowa State University Ames, IA 1

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 u Pain and suffering are clinically important conditions adversely affecting an animal’s quality of life (short-term or long-term) u Prevention and alleviation of animal pain and suffering (i.e., management) are important goals 1 IASP,

ProceduresManagement Procedures Disease Painful Events 4 Castration Tail docking Teeth clipping Reproductive surgery Repairs Lameness Shoulder ulcers Heal erosions Fractures Tail/vulva bites Injuries Lameness Mastitis Farrowing difficulties Respiratory disease GI disease

ProceduresManagement Procedures Disease Painful Events 5 Castration Tail docking Teeth clipping Reproductive surgery Repairs Lameness Shoulder ulcers Heal erosions Fractures Tail/vulva bites Injuries Lameness Mastitis Farrowing difficulties Respiratory disease GI disease Castration Tail Docking

Castration Removal of testicles or destruction of testicular formation 2 – 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 6 2 Petherick, 2010 Mcglone, 2014

Tail Docking Portion of tail removed – Prevent/Decrease tail biting – Decrease economic loss associated with reduction in growth performance and increased incidence of infection Pain associated with physical removal 3 7 Liat Romme Thomsen, Sutherland et al, 2011

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/Epinephrine 5 effects on: Heart rate Glucose levels Lactate levels **Physiological measures can also increase due to general arousal and handling** 9 4 Prunier et al, 2005; 5 Hay et al 2003

Physiological Measures Immune function 6 – Acute phase proteins – Pro-inflammatory cytokines – Antibody response **May result in greater welfare concerns if animal’s health is compromised** 10 Wikipedia, Moya et al, 2008

Behavioral Measures Behavioral changes – Locomotion and Posture 7 Head turning toward hindquarters Hind leg lifting Slow twitching tail – Maintenance behaviors 8 Reduced feeding Reduced drinking Reduced activity 11 7 Wemelsfeder and van Putten, 1985; 8 McGlone and Hellman, 1988

Vocalization Behavioral indicator of pain 9 – Immediate vocal response – High frequency calling – Increased calling rate 12 9 Xin et al, 1989

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) Smith and Modric, Coetzee, 2011

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 – CO 2 Gas – Isoflurane Analgesics – NSAIDs 18

Local anesthetics Local Most commonly used pain relieving drug in food animal medicine 12 Produces loss of sensation without loss of consciousness by preventing and blocking nerve impulses – Lidocaine/Prilocaine **Short Acting** Muir et al, 1995

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 – Co 2 – Isoflurane – Sevoflurane **Short Acting** 21

Analgesics Non-steroidal anti- inflammatory 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

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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 30

THANK YOU VERY MUCH FOR YOUR ATTENTION QUESTIONS? 31