1. Pain and injury Adroaldo J. Zanella ANS 305

2. Introduction 4 Freedom from physical discomfort and pain 4 Freedom from injury and disease –Animal welfare codes/laws in many parts of the world.

3. Introduction 4 Animals are capable of an experience which they avoid, given the opportunity, and which can dominate their physiology and behavior in a similar way to the experience of pain in man (Flecknell & Molony, 1997)

4. Pain 4 Pain is a sensation which, without involving higher level brain processing such as that associated with fear, is very aversive.

5. Pain –Nociceptive neurons –Some degree of tissue injury –Protective motor reactions –Emotional responses –Learned avoidance behavior –Modify social or other behavior

6. Animal pain 4 Comparative anatomy, physiology and behavior indicates that animal pain is similar to that in humans (National Research Council, 1992, Short and van Poznak, 1992)

7. Recognition of animal pain 4 Anthropomorphism –Help to recognize acute pain –Fail to identify chronic pain

8. Chronic pain 4 Animals may be hyperalgesic to certain types of noxious stimuli !

9. Legislation 4 Laboratory animals –Extensive legislation in the USA and European countries (LASA, 1990; NRC, 1992; FELASA, 1994) 4 Farm animals –Some laws in Europe; limited discussion in the USA Humane slaughter Husbandry procedures

10. My work 4 Responses of piglets to castration –Stress hormones were higher for more than 24 post surgery in animals castrated with no anesthesia compared to control pigs (e.g. anesthesia) 4 Responses of foals to branding –Foals that were branded showed higher physiological responses to hoof trimming than non-branded controls

11. Assessment of pain 4 Behavior –Vocalization –Time budget –Posture –Food and water intake 4 Physiology –Glucocorticoids –Opioids

12. Stress axis Hypothalamus CRF Anterior Pituitary= ACTH ß-endorphin Adrenal: Cortex= Glucocorticoids Medulla= Catecholamines

13. Occurrence of pain 4 Wild animals: –Some hunting techniques –Pest control

14. Occurrence of pain 4 Farm animals: –Housing –Transportation –Slaughter techniques –Genetic selection –Injuries –Husbandry procedures –Training techniques (Tennessee Walker)

15. Occurrence of pain 4 Leg injuries, lameness, impaired locomotion: –Pigs: –Cattle –Sheep –Horses –Poultry –Turkey

16. Occurrence of pain 4 Husbandry procedures (without anesthesia): –Castration –De-horning –Tail-docking –De-beaking –Branding

17. Occurrence of pain 4 Companion animals –Genetic selection (hip displasia) –Injuries –Surgical procedures Declawing Debarking Ears cropping

18. Occurrence of pain 4 Laboratory animals: –Experimental procedure –Genetic selection –Housing –Deliberately induced painful conditions

19. Failure to Alleviate Pain 4 Analgesic drugs are not used regularly by veterinarians (Townsend, 1987: 30-50%; Dohoo & Dohoo, 1996:49%).

20. Additional information 4 Recent textbooks are more informative 4 New compounds are available 4 Growing food safety concerns –Casualty slaughter 4 Controlled substances (how to handle) 4 Existence of legislation restricting the use of analgesics in food animals 4 Costs

21. The future 4 New compounds (UK): Butorphanol, buprenorphine, flunixin, carprofen, ketoprofen, meloxicam 4 Work on laboratory animals may help farm animals 4 Public perception of farming procedures may accelerate the necessary changes 4 We should play an active role