Farm Animal Anesthesia

Contributing authors xii Preface xiii 1 Preanesthetic considerations 1 HuiChu Lin Positioning 2 Ruminal tympany 3 Regurgitation 3 Salivation 4 Malignant hyperthermia 6 Differences in sensitivity to anesthetics 6 Preanesthetic preparation 8 References 13 2 Commonly used preanesthetics 17 HuiChu Lin Acepromazine (phenothiazine derivatives) 18 Cattle 18 Small ruminants and camelids 19 Swine 19 Droperidol and azaperone (butyrophenone derivatives) 19 Detomidine, medetomidine, romifidine, and xylazine (alpha2 agonists) 20 Cattle 21 Small ruminants and camelids 24 Swine 27 Atipamezole, tolazoline, and yohimbine (alpha2 antagonists) 28 Diazepam and midazolam (benzodiazepine derivatives) 29 Cattle, small ruminants, and camelids 30 Swine 30 Chloral hydrate 31 References 31 3 Standing sedation and chemical restraint 39 HuiChu Lin Cattle 39 Small ruminants and camelids 42 Swine 48 References 57 4 Injectable anesthetics and field anesthesia 60 HuiChu Lin Injectable anesthetics 61 Ketamine 61 Telazol 64 Propofol 66 Guaifenesin 68 Field anesthesia 68 Cattle 68 Small ruminants and camelids 72 Swine 80 References 87 5 Inhalation anesthesia 95 HuiChu Lin Cattle 101 Small ruminants and camelids 103 Swine 104 References 106 6 Perioperative monitoring and management of complications 111 HuiChu Lin Perioperative monitoring 111 Supportive fluid therapy 116 Positioning 121 Recovery 123 Perioperative complications 123 Regurgitation and aspiration pneumonia 123 Airway obstruction 124 Ruminal tympany/bloat 125 Salivation 126 Hypoventilation 126 Cardiac arrhythmias 127 Hypotension 128 Hypothermia 129 Malignant hyperthermia 130 Postanesthetic neuromyopathy 131 Cardiovascular collapse 131 References 132 7 Local and regional anesthetic techniques 136 Misty A. Edmondson Local anesthetics 136 Anesthesia for dehorning 137 Nasal anesthesia 137 Anesthesia of the eye 139 Eyelid 139 Eye and orbit 139 Anesthesia for laparotomy 141 Proximal paravertebral nerve block 141 Distal paravertebral nerve block 142 Inverted-L block 142 Line block 143 Anesthesia for reproductive procedures 144 Caudal epidural anesthesia 144 Continuous caudal epidural anesthesia 146 Lumbosacral epidural anesthesia 147 Sacral paravertebral nerve block 148 Internal pudendal nerve block 149 Dorsal penile nerve block 150 Castration 151 Teat anesthesia 152 Inverted-V block 152 Ring block 152 Infusion of teat cistern 152 Anesthesia of the distal limb 153 References 154 8 Anesthetic management for specific procedures 155 Benjamin Newcomer and Paul Walz Umbilical hernias 156 Wounds, lumps, bumps, and abscesses 157 Wound management 157 Ocular squamous cell carcinoma 158 Enucleation 158 Entropion 159 Abscess removal 159 Surgical disorders of the abdomen 159 Laparotomy 159 Disorders of the forestomachs 161 Displacements and volvulus of the abomasum 162 Small intestine disorders (intussusception, intestinal volvulus, intestinal obstruction) 162 Urolithiasis and ruptured urinary bladder 163 Urogenital surgery in the female 164 Cesarean section 164 Ovariectomy 165 Vaginal prolapse 166 Perineal laceration 166 Urogenital surgery in the male 166 Castration 166 Penile translocation 168 Persistent frenulum 169 Penile papilloma 169 Epididymectomy 169 Vasectomy 169 Musculoskeletal indications 170 Dehorning 170 Claw amputation 171 Excision of interdigital fibromas 171 Tail docking 171 Rectal prolapse 172 References 172 9 Pain management for farm animals 174 HuiChu Lin Local anesthetics 177 Systemic pain management 178 Opioid analgesics 178 Nonsteroidal anti-inflammatory drugs 183 Alpha-2 agonists 187 Ketamine 188 Gabapentin 188 Drug combinations for pain management 189 Constant rate infusion 190 Local or regional analgesia 197 Caudal epidural analgesia 197 Lumbosacral epidural anesthesia 198 Intra-articular analgesia 200 References 204 10 Fluid therapy 215 Paul Walz General considerations 215 Physiology of body fluids 216 Patient assessment 218 Fluid and electrolyte therapy in the perioperative period 219 Quantity and rate of fluid administration 220 Fluid type 221 Method of administration 224 Monitoring fluid administration 226 References 227 11 Regulatory and legal considerations of anesthetics and analgesics used in food-producing animals 228 Thomas Passler Alpha-2 agonists 231 Barbiturates 233 Benzodiazepines 233 Dissociative anesthetics 234 Local anesthetics 235 Opioids 236 Nonsteroidal anti-inflammatory drugs 238 Phenothiazine derivatives 241 Propofol 241 References 243 12 Euthanasia of farm animals 248 Thomas Passler Considerations prior to euthanasia 248 The process of euthanasia 251 Methods of euthanasia 251 Injectable euthanasia drugs 252 Physical methods 253 Adjunctive and other methods of euthanasia 257 Considerations subsequent to euthanasia 258 References 259 Index 263