Equine Acute Abdomen

Nathaniel A. White, James N. Moore, Tim S. Mair

• ContentsPart 1. Normal Anatomy and PhysiologyChapter 1 Gross and Microscopic Anatomy of the Equine Gastrointestinal TractThomas M. Krunkosky, Carla Jarrett, and James N. MooreEsophagus 5Esophagus-Stomach Junction 7Stomach 7Stomach-Small Intestine Junction 11Small Intestine 11Large Intestine 14Liver 17Spleen 18Pancreas 19Chapter 2 Physiology of the Digestive Tract Gastric Secretory Function – Michael J. Murray 22Small Intestine Function – David E. Freeman 25Digestive Physiology – Anatomy 25Intraluminal Digestion 28Absorption of Ions and Water 29Absorption of Carbohydrate, Protein and Fat 32Iron Absorption 33Calcium and Magnesium Absorption 34Intestinal Secretion 35Motility 36Control of Motility 37Function of the Ileum 38Large Bowel Function – Marco A.F. Lopes 41Motility Patterns and Transit of Contents 41Microbial Activity and Fermentation 42Secretion and Absorption 45Liver Function – Tim S. Mair 54Bile Acid Metabolism and Excretion of Bile 54Protein Metabolism 54Carbohydrate Metabolism 55Lipid Metabolism 55Detoxification and Drug Metabolism 56Storage 56Chapter 3 Effects of Feeding on Equine Gastrointestinal Function or PhysiologyMarco A.F. LopesFeeding Grain 58Feeding Lush Grass 62Replacing Grain With Fat 62Feeding Mature Grass and Poor Quality Hay 62Feeding Large Meals Intermittently and Fasting 62Chapter 4 Intestinal Motility and TransitPeter C. RakestrawPhysiology of Normal Motility 68Pathophysiology of Ileus 80Treatment of Motility Disorders in the Horse 82Part 2 Pathophysiology of Gastrointestinal DiseasesChapter 5 Pathophysiology of Gastric Ulcer DiseaseMichael J. MurrayGastric Ulcer Disease 96Chapter 6 Pathophysiology of Gastrointestinal Disease: Obstruction and StrangulationAnthony T. BlikslagerSimple Obstruction 100Strangulating Obstruction 101Intestinal Reparative Mechanisms 107Chapter 7 Prevention and Treatment of Postoperative Intraabdominal Adhesions in HorsesP.O. Eric MuellerCurrent Concepts in Pathophysiology of Adhesion Formation 119Diagnosis of Intraabdominal Adhesions 120Current Concepts in Prevention of Adhesion Formation 121Separation of Adhesiogenic Surfaces 122Treatment of Intraabdominal Adhesions 125Adhesion Prevention Strategies 125Chapter 8 Pathophysiology of PeritonitisJohn F. PeroniAnatomy and Physiology of the Peritoneum 130Etiology of Peritonitis 131Clinical Presentation 131Diagnostic Approach 132Chapter 9 Pathophysiology of Enteritis and ColitisHarold C. McKenzieInflammation 136Pain 137Ileus 137Hypermotility 137Hypersecretion 138Osmotic Diarrhea 138Decreased Absorption 138Endothelial Dysfunction 138Specific Diseases 138Chapter 10 Malabsorption SyndromesTim S. Mair and Thomas J. DiversCauses of Malabsorption Syndrome 148Clinical Signs 155Diagnosis 156Treatment 158Chapter 11 Liver Diseases and Liver FailureTim S. Mair and Thomas J. DiversCauses of Liver Disease 162Diagnosis of Liver Disease 165Hyperlipemia 167Theiler’s Disease (Serum Hepatitis) 174Other Causes of Acute Hepatic Disease and Failure in Adult Horses 178Pyrrolizidine Alkaloid Intoxication 178Cholangiohepatitis and Choledocholithiasis 182Other Biliary Conditions 185Chronic Active Hepatitis 185Klein Grass (Panicium Coloratum) Toxicity 186Alsike Clover Toxicity 186Hepatic Neoplasia 187Hepatic Amyloidosis 187Iron Overload, Hemochromatosis 187Right Hepatic Lobe Atrophy 188Chapter 12 Systemic Inflammatory Response Syndrome: Endotoxemia ReconsideredClare E. Bryant and James N. MooreResponses to Pathogen-Associated Molecular Patterns 192Receptors for Gram-Negative Bacteria and Bacterial Ligands 193Receptors for Gram-Positive Bacteria and Bacterial Ligands 195Systemic Inflammatory Response Syndrome 196Inflammatory Mediators and Their Source in the Horse 197Part 3. Intestinal ParasitismChapter 13 Intestinal ParasitismChristopher J. ProudmanPrinciples of Iintestinal Parasitism 204Strongylus Vulgaris 204Cyathostomins 207Tapeworms 208Parascaris Equorum 210Other Intestinal Parasites 211Prevention 211Part 4. EpidemiologyChapter 14 Epidemiology of ColicNoah D. CohenGeneral Epidemiologic Considerations 218Incidence of Colic 222Factors that Predispose to Colic 222Factors Indicating the Need for Surgical Management of Colic 225Frequency of and Factors Associated with Survival from Colic and Colic Surgery 226Study of Colic Problems in Individuals and Herds 228Part 5. DiagnosisChapter 15 Diagnosis of Gastrointestinal DiseaseEmma L. Rowe and Nathaniel A.WhiteSignalment 236History 237Physical Examination 238Hematology, Blood Gases, and Serum Biochemistry 270Ultrasonography 271Radiographs 276Endoscopy 278Laparoscopy 280Fecal Examination 280Transit Time 281Exploratory Laparotomy 281False Colic 281Decision for Surgery 282Part 6. Medical ManagementChapter 16 Medical Management of Gastrointestinal DiseasesTim S. MairAnalgesia 292Choice of Analgesics in Colic 297Treatment of Intestinal Spasm and Spasmodic Colic 298Treatment of Obstruction 298Treatment of Flatulence and Tympany 302Treatment of Ileus 303Chapter 17 Treatment of ShockKevin T. T. CorleySupport of the Cardiovascular System 310Fluid Therapy 310Acid Base Balance 312Types of Fluid 316Oral Fluids 324Delivery Systems 326Recognition of Hypovolemia and Dehydration 327Treatment Strategies 329Chapter 18 Treatment of EndotoxemiaKevin T. T. Corley and Gayle D. HallowellDrugs that Bind or Block Endotoxin 338Anti-Inflammatory Agents 340Modulation of the Coagulation System 342Drugs Affecting Intracellular Metabolism 344Chapter 19 Treatment of PeritonitisJohn F. PeroniMedical Treatment 352Interventional Treatment 352Complications and Prognosis 354Chapter 20 Diagnosis and Treatment of Enteritis and Colitis in the HorseHarold C. McKenzieDiagnosis 356Specific Syndromes 356Treatmen 360Supportive Therapies 360Specific Therapies 366Surgery 369Specific Diseases 370Chapter 21 Nonsurgical Management of Nephrosplenic Entrapment of the Large ColonJoanne HardyClinical Presentation 383Diagnosis 383Nonsurgical Correction 385Complications and Prognosis 387Prevention of Recurrence 387Chapter 22 Colic in the FoalMartin O. FurrAbdominal Radiography 391Gastroendoscop 393Ultrasonography 393Abdominocentesis 394Case Synthesis and Management 395Surgical Treatment 396Gastroduodenal Ulceration 397Small-Intestinal Obstruction 397Large-Colon Obstruction 397Atresia 398Part 7. Nutritional ManagementChapter 23 Nutritional Management of the Colic PatientRay J. GeorRationale for Early Initiation of Nutritional Support after Colic and Intestinal Surgery 404Estimating Nutrient Requirements 405Modes of Nutritional Therapy 406Feeding Management of Specific Gastrointestinal Conditions 412Part 8. Anesthesia for Abdominal SurgeryChapter 24 Anesthesia for Horses with ColicCynthia M. TrimPreanesthetic Assessment 420Anesthetic Agents 421Induction of Anesthesia 422Maintenance of Anesthesia 422Anesthetic Agents in Foals 424Monitoring 424Cardiovascular Support 428Hypercapnia and Hypoxemia 434Airway Management 435Recovery from Anesthesia 436Anesthesia for Surgery in the Standing Horse 437Part 9. Surgery for Acute Abdominal DiseaseChapter 25 Preparation of the PatientDavid E. FreemanPatient Preparation 444Antiseptics Agents 445Draping the Surgery Site 446Chapter 26 Surgical Exploration and ManipulationDavid E. FreemanVentral Midline Incision 452Inguinal Approach 454Flank Laparotomy 455Alternative Approaches 455Abdominal Exploration 456Examination and Handling of Small Intestine 468Examination and Handling of Large Intestine 469Special Circumstances 470Intestinal Placement 472Chapter 27 Surgical TechniquesDavid E. FreemanSurgical Team 474Surgical Environment and Equipment 475Gowns, Drapes and Accessories 476Decompression and Drainage 477Laparotomy Sponges 482Surgical Instruments and Suture 482Stapling Instruments 485Miscellaneous Instruments 489Surgical Procedures in the Small Intestine 489Chapter 28 Intestinal ViabilityDavid E. FreemanSmall Intestine 502Large Colon and Cecum 509Small Colon 510Chapter 29 Large-Colon Enterotomy, Resection and AnastomosisJoanne HardyLarge-Colon Enterotomy 514Large Colon Resection 516Chapter 30 Small Intestinal Resection and AnastomosisDavid E. FreemanExtent of Resection 522Resection of Mesentery 522Decompression 522Resection and Anastomosis 523Stoma Size 525End-to-End Anastomosis 527Stapled Jejunojejunostomy 528Everted Triangulated Stapled Anastomosis 530Stapled versus Handsewn Anastomoses for Jejunojejunostomy 530Jejunoileostomy 531Jejunocecal and Ileocecal Anastomoses 532Pelvic Flexure Colotomy 536Chapter 31 Abdominal ClosureDavid E. FreemanClosure of the Peritoneum 540Linea Alba Closure 540Techniques and Principles 543Subcutaneous Closure and Skin 544Incisional Dressing 545Recovery Stall 545Abdominal Bandages 545Postoperative Care 546Healing of the Equine Linea Alba 546Special Circumstances 547Secondary Closure 548Part 10. Intensive Care and Postoperative CareChapter 32 Monitoring Treatment for Abdominal DiseaseTim S. Mair and Thomas J. DiversFrequency of Examinations 554Physical Examinations 554Monitoring Clinical Pathology Parameters 560Chapter 33 Postoperative ComplicationsChristopher J. ProudmanPostoperative Colic 564Postoperative Ileus (POI) 565Jugular Thrombosis and Thrombophlebitis 566Incisional Infection 568Incisional Hernia Formation 569Adhesions 570Laminitis 572Part 11. Specific DiseasesChapter 34 Diseases of the StomachMichael J. MurrayGastric Ulcer Syndromes 578Gastric Impaction 582Gastric Dilation 583Neoplasia 583Chapter 35 Liver Diseases In FoalsTim S. Mair and Thomas J. DiversPortosystemic Shunts 586Tyzzer’s Disease 586Equine Herpes Virus 1 Hepatitis 588Liver Failure in Foals after Neonatal Isoerythrolysis 588Umbilical Vein Abscess Affecting the Liver 589Portal Vein Thrombosis 589Hyperammonemia of Morgan Foals 590Bile Duct Obstruction 590Toxic Hepatopathy 591Chapter 36 Diseases Of The Small IntestineDavid E. FreemanStrangulating Obstruction 594Nonstrangualting Obstruction 605Inflammatory and Infiltrative Diseases 610Chapter 37 Diseases of the Cecum; Cecocecal and cecocolic intussusceptionJames N. Moore and Joanne HardyCecal Tympany 618Cecal Impaction 619Cecocecal and Cecocolic Intussusception 622Chapter 38 Specific diseases of the large colonJoanne HardyLarge-Colon Tympany 628Large Colon Impaction 628Sand Impaction 631Enterolithiasis 633Large-Colon Displacement 634Other Simple Obstructions of the Large Colon 639Large-Colon Torsion/Volvulus 639Right Dorsal Colitis 642Mural Infarction (Thromboembolic Colic) 644Other Strangulating Lesions of the Large Colon 644Chapter 39 Disorders of the Small ColonJohn F. PeroniSurgical Considerations Affected by Anatomic Features of the Small Colon 650Obstructive Lesions 651Vascular and Strangulating Lesions 656Chapter 40 Vascular and strangulating lesionsPeter C. RakestrawAnatomy 660Etiology and Prevention 660Location and Classification of Rectal Tears 660Clinical Signs and Diagnosis 662Emergency Management 663Medical Management 664Surgical Management 665Temporary Indwelling Rectal Liner 665Loop Colostomy 666Primary Repair 671Nonvisual Direct Suturing Per Rectum 671Ventral Midline Exposure and Antimesenteric Enterotomy for Suture Repair 673Prognosis and Recommendations 674Chapter 41 Colic and PregnancyElizabeth M. SantschiColic during Pregnancy 678Colic in the Peripartum Period 683Chapter 42 Colic From Alternative Systems – “False Colics”Tim S. MairPain Associated with the Female Reproductive Tract 689Pain Associated with the Male Reproductive Tract 695Pain Associated with the Urinary Tract 695Liver Diseases 697The Pancreas 697The Spleen 698Pain Associated with the Respiratory Tract 698Pain Associated with Cardiovascular Disease 700Pain Associated with the Musculoskeletal System 700Chapter 43 Abdominal InjuriesJohn F. PeroniDiagnostic Approach 704Treatment 707Chapter 44 Laminitis Associated with Acute Abdominal DiseaseJames K. Belknap and Andrew H. ParksPathogenesis 710Clinical Presentation 716Treatment 719Index 731