Misconceptions of capture- induced hyperthermia Leith Meyer - PDF document

Misconceptions of capture- induced hyperthermia Leith Meyer Director Centre for Veterinary Wildlife Management & Associate Professor Senior Honorary Research Fellow Department Paraclinical Sciences Brain Function Research Group - Pharmacology & Toxicology Wildlife Conservation Physiology Faculty of Veterinary science School of Physiology Onderstepoort University of the Witwatersrand Email address: Leith.meyer@up.ac.za Braamfontein 44 Body temperature ( ° C) 42 40 38 2 1

44 Body temperature ( ° C) 42 40 38 3 Effects of hyperthermia  Heat cytotoxicity  Disrupts metabolic pathways  Energy supplies  Enzymatic function  Disrupts membrane structures  Increases cellular metabolism (oxygen + energy substrates)  Cell damage and death 4 2

Anthropomorphic delusions 5 Anthropomorphic delusions  The cause of capture-induced hyperthermia  Heat stroke 6 3

Anthropomorphic delusions Exercise or Heat 7 44 Body temperature ( ° C) 42 40 38 8 4

44 Body temperature ( ° C) 42 40 38 9 Environmental conditions “Don’t capture animals in the heat of the day because they will get too hot” 10 5

Body temperature ( o C) 41 40 39 38 37 0:00 6:00 12:00 18:00 Time of day 11 Body temperature ( o C) 41 40 39 38 37 0:00 6:00 12:00 18:00 Time of day 12 6

Environmental conditions 35 Air temeprature (  C) 30 25 20 15 0:00 6:00 12:00 18:00 Time of day 14 7

Environmental conditions Ambient temeprature (  C) Body temperature ( o C) 41 35 40 30 39 25 38 20 37 15 0:00 6:00 12:00 18:00 Time of day 15 Environmental conditions 60 Air Temperature ( 0 C) Black Globe 50 40 30 20 10 0:00 6:00 12:00 18:00 Time of day 16 8

Environmental conditions A 3 2 Body temperature change ( o C) 1 0 26 30 34 38 42 Dry bulb temperature ( o C) B 3 2 1 0 30 34 38 42 46 50 Black globe temperature ( o C) 17 Activity 18 9

Activity Body temperature ( o C) 40 50 Activity counts 40 39 30 38 20 37 10 36 0 0:00 6:00 12:00 18:00 Time of day 19 Activity Body temperature ( o C) 50 Activity counts 40 40 30 39 20 10 38 0 11:00 13:00 15:00 17:00 Time of day 20 10

Activity Body temperature ( ° C) 42 40 38 4 8 12 16 20 Time of day 21 Drug effects 22 11

Drug effects “ Opioids are adrenergic and heat is generated by changes in metabolic rate when they are used” Opioids can cause both hyperthermia or hypothermia Poikilothermia – sedative, tranquilizers, general anaesthetics 23 No drugs required for hyperthermia Body temperature ( ° C) 42 40 38 4 8 12 16 20 Time of day 24 12

+ Tranquilizer/sedative Immobilizing agents • Azaperone • Etorphine (M99) • Thiafentanil (Thianil) • Medetomidine 25 Drug effects 800 Time to recumbency (s) 600 400 200 0 Etor+Azap Etor+Med Thia+Azap Thia+Med 26 13

Drug effects Etorphine + azaperone 42 Etorphine + medetomidine Body temperature ( o C) Thiafentanil + azaperone 41 Thiafentanil + medetomidine 40 39 38 0 60 120 180 240 Time (min) 27 Drug effects B ody tem perature 2 change ( o C ) 1 0 Etor+Azap Etor+Med Thio+Azap Thio+Med 28 14

Stress 29 Stress 42 Body temperature ( o C) 41 40 39 38 37 Days 30 15

Stress 3 Temperature change ( o C) 2 1 0 0 25 50 75 100 125 150 Cortisol (nmol l -1 ) 31 Naïve 2 month 5 month 32 16

175 150 Cortisol (nm ol l -1 ) 125 100 75 50 25 0 Naïve 2 month 5 month 33 A Body temperature change ( o C) 4 3 2 1 0 B 200 Cortisol (nmol l -1 ) 100 0 Naïve 2 month 5 month 34 17

35 Anthropomorphic delusions  The cause of hyperthermia  Heat stroke  Stress (stress-induced hyperthermia)  Capture when it feels good for us 36 18

Anthropomorphic delusions 37 Environmental conditions “All captures should be performed in the cool , early hours of the morning or late afternoon .” 38 19

Environmental conditions Ambient temeprature (  C) Body temperature ( o C) 41 35 40 30 39 25 38 20 37 15 0:00 6:00 12:00 18:00 Time of day 39 Environmental conditions Body temperature ( o C) 42 Winter 41 Summer 40 39 38 37 36 35 0:00 6:00 12:00 18:00 Time of day 40 20

Environmental conditions “Don’t capture animals in the heat of the day because they will get too hot” A 3 2 Body temperature change ( o C) 1 0 26 30 34 38 42 NB: Post capture Dry bulb temperature ( o C) B • Drugs effects 3 • Placement of animals 2 1 0 30 34 38 42 46 50 41 Black globe temperature ( o C) Environmental conditions “Don’t capture animals when ambient conditions are above 25 o C” 42 21

Environmental conditions “Don’t capture animals when ambient conditions are above 25 o C” Wet-Bulb Globe Temperature 43 Environmental conditions “Don’t capture animals when ambient conditions are above 25 o C” Wet-Bulb Globe Temperature 44 22

Environmental conditions “Don’t capture animals when ambient conditions are above 25 o C” Wet-Bulb Globe Temperature 45 Anthropomorphic delusions  The cause of hyperthermia  Heat stroke  Capture when it feels good for us  Human cooling practices should work well in animals too. 46 23

Anthropomorphic delusions 47 Temperature change: 1 Temperature (ºC) 0 -1 -2 -3 -4 l e V t C o s c I º r i i m 8 t n 2 o C In 1 hour 48 24

49 Anthropomorphic delusions  The cause of hyperthermia  Heat stroke  Capture when it feels good for us  Human cooling practices should work well in animals too. 50 25

Anthropomorphic delusions  The cause of hyperthermia  Heat stroke  Capture when it feels good for us  Human cooling practices should work well in animals too.  Hyperthermia is the root of all evil during capture 51 Consequences of Hyperthermia Cellular function Oxygen demand (Q10) Tissue damage Organ failure Death (capture myopathy) 52 26

Pathophysiological effects of capture and efficacy of cooling hyperthermia Animal Groups Chase camp HNC H+C c c HNC H+C c HNC H+C HNC 27

Rectal Temperature °C N: 38-39°C 2 2 2 6 0 / / 1 3 y 1 2 a y y - - D a a 0 0 D D y y a a D D Rectal Temperature °C N: 38-39°C cooling 2 2 2 6 0 / / 1 3 1 2 y a y y - - D a a 0 0 D D y y a a D D 28

Nv: 0-5 mmol /L cooling N: 0-8 IU/L: cooling 29

N: 50-271 IU/I : cooling N ranges: Blesbok: 0,021ng/ml Dogs: 0,02 ng/ml Cats: 0,03-0,16 ng/ml Horses: 0,047 ng/ml cooling 30

Effects of Hyperthermia  Maybe capture-induced hyperthermia is not the root of all evil  But an indication of the evil that we have done!!!! 62 31

Conclusion 63 Anthropomorphic delusions  The cause of hyperthermia  Heat stroke 64 32

65 Anthropomorphic delusions  The cause of hyperthermia  Heat stroke  Capture when it feels good for us 66 33

Environmental conditions “Don’t capture animals when ambient conditions are above 25 o C” Wet-Bulb Globe Temperature 67 Anthropomorphic delusions  The cause of hyperthermia  Heat stroke  Capture when it feels good for us  Human cooling practices should work well in animals too. 68 34

69 Anthropomorphic delusions  The cause of hyperthermia  Heat stroke  Capture when it feels good for us  Human cooling practices should work well in animals too. 70 35

Anthropomorphic delusions  The cause of hyperthermia  Heat stroke  Capture when it feels good for us  Human cooling practices should work well in animals too.  Hyperthermia is the root of all evil during capture 71 Effects of Hyperthermia  But an indication of the evil that we have done!!!! 72 36

Prevention better than cure Minimise stress • Short + slow chases • Quick induction times • Optimal drug combination • Right doses – higher better than lower (side-effects) • Minimize loud noises and handle animals with care (quickly) • Ensure animals are place where they don’t gain, but can lose heat • If hyperthermic the damage is done • Still cool to prevent further damage 73 Thank you 37