Anaesthesia in reptiles Zdenek Knotek, DVM, PhD Avian and Exotic Animal Clinic University of Veterinary and Pharmaceutical Sciences Brno Czech Republic

Sedation

big tranquillisers (chlorpromazine 10 mg/kg IM) small tranquillisers (diazepam 0.20 – 0.60 mg/kg IM) tiletamine/zolazepam

efficient

Tiletamine

2 (ethylamino)-2-(2thienyl)cyclohexanon

phencyclidine derivat (50 % of the phenc. effect) 2 - 3x stronger than ketamine dissociative anaesthetics

Dissociative anaesthetics + induce diminished tone and reduced impulse transmission - without muscle relaxation - have a limited capacity of inducing visceral analgesia - are not appropriate for use as stand-alone anaesthetic in larger and abdominal surgeries

Zolazepam

4 - (-o- Fluorophenyl)-6, 8-dihydro-1,3,8, trimethyl-pyrazolo(3,4e)(1,4)diazepin-7(1H)-one) benzodiazepin-family

Tiletamine - zolazepam + safety analgesia and myorelaxation free of side effects

- dependence on metabolism eliminated by liver + kidneys Tilest, Telazol, Zoletil

1:1

Indications for tiletamine-zolazepam anaesthesia in reptiles safe handling and transportation of aggressive lizards sedation and immobilization during some examinations (radiography, MRI, endoscopy, USG, biopsy) preparing intubation before inhalation anaesthesia (crocodiles, chelonians aggressive lizards, poisonous snakes)

Anaesthesia Injection or inhalation anaesthesia for reptiles? Injection optimal site ? active metabolism (kidney, liver) !!! recovery (long-lasting) !!! antidote regulation !!! BW influence price (drug, equipment) Inhalant metabolism + equipment !!! price ? technique (intubation in agressive - dangerous animals)

Isoflurane only 0.3% is metabolised in the body fast onset of deep surgical anaesthesia fast recovery - free of complications excellent myorelaxation in patients with renal or hepatic damage does not irritate the myocardium

Isoflurane

Lizards < 1 kg > 1 kg

Premed.

Form

+

mask 5% 1,5 - 2,5% intubation 4 - 5% 1,5 - 2,5%

Snakes +/Turtles + Crocodiles +

Induction

intubation int./mask intubation

5% 5% 4%

Surgery

1,5 - 2% 3–4% 1–2%

Crocodiles Trachea

closed with the valve

Introduction

tiletamine/zolazepam

Surgery

isoflurane

Tiletamine - zolazepam Crocodiles Crocodiles

5 - 10 mg/kg IM sedative 10 – 40 mg/kg IM surgery 1 - 2 mg/kg IM

Crocodiles

4 - 8 mg/kg IM

Crocodiles

5 mg/kg IM

Crocodiles

induction immobilization

2 - 8 mg/kg IM induction

Lloyd (1999) Lloyd (2003) Fleming (2001) Haagner and Reynolds (1992)

Turtles, tortoises, terrapins Glottis

base of the tongue

Introduction

tiletamine/zolazepam

Surgery

isoflurane

Patient monitoring and control - chelonians reflexes head, neck, and leg/tail reflex jaw tone - turtles and terrapins skin sensitivity - disappear in deep palpebral reflex anaesthesia pulse oximetry

Tiletamine - zolazepam Chelonians

5 - 10 mg/kg IM

Raphael (2003)

good muscle relaxation

Chelonians

3 - 14 mg/kg IM

Chelonians

10 - 30 mg/kg IM

not enough

good muscle relaxation

4 - 88 mg/kg IM

Chelonians

not enough for surgery

Chelonians

3 - 5 mg/kg IM induction

45 mg/kg IM intubation 90 mg/kg IM minor surgery 15 - 20 mg/kg IM Chelonians Chelonians

restraint, intubation

Schobert (1987) Frye (1991) Boever and Caputo (1982) Heard (2001) Apelt (1993)

60 - 90 mg/kg IM Risk – kidneys/liver

Snakes Glottis opens in the floor of the mouth cavity Direct intubation easy Mask Introduction Surgery

tiletamine/zolazepam isoflurane

Patient monitoring and control - snakes reflexes head, neck, and frontal body lifting reflex righting reflex - fast correction of position skin sensitivity - disappears in deep anaesthesia pulse oximetry

Tiletamine - zolazepam Snakes

3 - 5 mg/kg IM

Mitchell (2003)

minor surgery

Snakes

25 mg/kg IM rapid and safe sedation

Snakes

15 mg/kg IM

Snakes

15 - 29 mg/kg IM

Snakes

3 - 5 mg/kg IM

Snakes

5 - 10 mg/kg IM

Snakes

15 - 30 mg/kg IM

minor surgery

induction

immobilization

minor surgery

Stirl (1997) Schobert (1997) Gray et al. (1974) Heard (2001)

Lizards Glottis Direct intubation Mask Introduction Surgery

floor of the mouth cavity easy - difficult

tiletamine/zolazepam isoflurane

Patient monitoring and control - lizards reflexes head, neck, and frontal body lifting reflex skin sensitivity - disappears in deep anaesthesia pulse oximetry

Patient monitoring and control temperature blood pressure SpO2 heart frequence ventilation TCO2

Tiletamine - zolazepam Lizards

4 - 8 mg/kg IM

Heard (2001)

handling

Lizards

4 - 6 mg/kg IM immobilization

Lizards

10 - 15 mg/kg IM

Lizards

25 - 40 mg/kg IM

restraint, induction

surgery

Schumacher (2003)

Propofol short-lasting effect (20 minutes) IV turtles and tortoises 5 -10 mg/kg snakes 5 mg/kg lizards 5 - 10 mg/kg