Hematology Techniques for Veterinary Technicians

MEGAN MORGAN, BAS, RVTg, Department Chair, Veterinary Medical Technology, Central Carolina Community College.

WILLIAM CODY HECKER, AAS, RVT, Instructor, Veterinary Medical Technology Program, Central Carolina Community College, Sanford, North Carolina, USA.

Preface xii
Acknowledgments xiii
About the Companion Site xiv
Quick Reference of Laboratory Procedures xv

Section I Introduction to Hematology 1

1 Introduction to Hematology 3
1.1 What Is Hematology? 3
1.2 The History of Hematology 3
1.3 Evolution of Veterinary Hematology 5
1.4 The Role of Veterinary Technicians in Hematology 8
1.5 Components of Blood 9
1.6 Species-specific Considerations 12
1.7 Overview of Hematopoiesis 15
1.8 Common Blood Tests in Veterinary Practice 16
1.9 The Diagnostic Value of Blood 20
1.10 How Blood Reflects Disease Processes 21
1.11 Limitations of Hematology and the Importance of Correlation with Clinical Signs 23
1.12 Ethical and Legal Responsibilities in Hematology for Veterinary Technicians 25
1.13 Preparing for Success in Hematology 28
1.14 Summary 30

2 Hematopoiesis 35
2.1 Introduction to Hematopoiesis 35
2.2 Sites of Hematopoiesis 35
2.3 Hematopoietic Stem Cells 42
2.4 Erythropoiesis: RBC Production 45
2.5 Leukopoiesis: WBC Production 46
2.6 Thrombopoiesis: Platelet Production 51
2.7 Regulation of Hematopoiesis 52
2.8 Regeneration of Blood Cells After Loss or Destruction 56
2.9 Disorders and Diagnostic Overview 58
2.10 Summary 61

3 The Hematology Laboratory 65
3.1 Introduction to the Hematology Lab 65
3.2 Overview of Laboratory Setup and Safety 65
3.3 QC and QA in the Veterinary Laboratory 67
3.4 Common Laboratory Equipment 69
3.5 Summary 81

Section II Fundamentals of Hematological Testing 85

4 Blood Sample Collection and Handling 87
4.1 Introduction to Sample Collection and Handling 87
4.2 Sample Handling 87
4.3 Sample Labeling 96
4.4 Sample Storage 97
4.5 Sample Packaging 98
4.6 Summary 98

5 The Hematocrit and Associated Tests 102
5.1 Introduction to PCV, TS, Fibrinogen, and RBC Indices 102
5.2 PCV-The Hematocrit 103
5.3 TS Testing 105
5.4 Obtaining Fibrinogen Values 110
5.5 Interpreting PCV, TS, and Fibrinogen Together 113
5.6 Cell Count and Hemoglobin Estimations 114
5.7 RBC Indices 116
5.8 Buffy Coat Evaluation for Microfilaria 118\
5.9 Limitations and Artifacts 120
5.10 Summary 121

6 Preparing Blood Smears for the Differential Procedure 125
6.1 Introduction to Blood Smears and the Differential Procedure 125
6.2 Blood Smear Evaluation Overview 125
6.3 Blood Smear Preparation 125
6.4 Components of a Blood Smear 126
6.5 Techniques for Making High-quality Blood Smears 128
6.6 Common Staining Methods 137
6.7 Blood Smear Differential Procedure 140
6.8 Summary 147

7 Cellular Differentiation and Morphology 150
7.1 Introduction to Cellular Morphology 150
7.2 Normal Erythrocyte Morphology 150
7.3 Variations in Erythrocyte Morphology 152
7.4 Normal Leukocyte Morphology 158
7.5 Variations in Leukocyte Morphology 161
7.6 Thrombocyte Morphology 166
7.7 Variations in Thrombocyte Morphology 166
7.8 Summary 167

8 Performing Complete Blood Counts 172
8.1 Introduction to the Complete Blood Count 172
8.2 Manual CBC Methods 172
8.3 TIC Brand Systems: Leuko-TIC, Ery-TIC, and Thrombo-TIC 174
8.4 Best Practices in Manual Counting 180
8.5 Blood Smear Evaluation 181
8.6 WBC Counting and Differentiation 183
8.7 RBC Evaluation 185
8.8 Platelet Evaluation 186
8.9 Automated Analyzers and CBC Technology 189
8.10 Interpreting CBC Results 192
8.11 Advanced Diagnostics and Scatter Plots 196
8.12 Summary 197

Section III Advanced Hematology 201

9 Anemia 203
9.1 Introduction to Anemia 203
9.2 Approaching Anemia: Relative vs. Nonrelative 204
9.3 Grading Anemia: Mild, Moderate, Severe 206
9.4 Classifications of Anemia 212
9.5 Causes of Anemia 217
9.6 Diagnostic Approach to Anemia 219
9.7 Treatment and Management of Anemia 227
9.8 Prognosis and Monitoring 230
9.9 Clinical Relevance and the Technician's Role in Anemic Patients 231
9.10 Summary 233

10 Polycythemia 237
10.1 Introduction to Polycythemia 237
10.2 Types and Classifications of Polycythemia 239
10.3 Causes of Polycythemia 239
10.4 Clinical Signs and History 243
10.5 Diagnostic Approach 245
10.6 Treatment and Management 247
10.7 Prognosis and Long-term Considerations 249
10.8 Summary 251

11 Leukemia and Other Blood Cancers 255
11.1 Introduction to Hematologic Cancers 255
11.2 Classifications of Leukemia 255
11.3 General Clinical Signs and Diagnostic Clues 262
11.4 Leukemia in Dogs 265
11.5 Leukemia in Cats 269
11.6 Leukemia in Horses 271
11.7 Leukemia in Cattle 274
11.8 Leukemia in Other Species 276
11.9 Diagnostic Tools and Differentiation 278
11.10 Treatment and Management of Leukemia 280
11.11 Summary 283

12 Blood Parasites 287
12.1 Introduction to Blood Parasites 287
12.2 Transmission and Life Cycles 288
12.3 Common Blood Parasites in Domestic Animals 296
12.4 Morphologic Identification on Blood Smear 310
12.5 Clinical Signs and Hematologic Effects 312
12.6 Diagnostic Techniques 313
12.7 Treatment and Prognosis 318
12.8 Client Communication and Zoonotic Awareness 319
12.9 Summary 319

13 Coagulation Disorders and Other Hematologic Illnesses 324
13.1 Introduction 324
13.2 Disorders of Hemostasis and Coagulation 324x Contents
13.3 Diagnostic Evaluation of Hemostatic Disorders 334
13.4 Immune-mediated Hematologic Disorders 340
13.5 Overview of Other Hematologic Changes in Illness 345
13.6 Technician's Role in Recognizing and Responding to Hematologic Illness 348
13.7 Summary: Hematologic Disorders and Common Illnesses 350

14 Hematology of Nonmammalian Species 354
14.1 Introduction 354
14.2 Normal Reptilian and Amphibian RBCs 354
14.3 Variations in Reptilian and Amphibian RBCs 355
14.4 Normal Reptilian and Amphibian WBCs 355
14.5 Variations in Reptilian and Amphibian WBCs 357
14.6 Reptilian and Amphibian Thrombocytes 359
14.7 Hematological Testing Techniques for Reptiles and Amphibians 360
14.8 Anticoagulants 363
14.9 Normal Avian RBCs 363
14.10 Variations in Avian RBCs 364
14.11 Normal Avian WBCs 364
14.12 Variations in Avian WBCs 366
14.13 Avian Thrombocytes 367
14.14 Hematological Testing Techniques for Avians 368
14.15 Anticoagulants for Avian Samples 371
14.16 Normal Fish RBCs 371
14.17 Variations in Fish RBCs 372
14.18 Normal Fish WBCs 372
14.19 Variations in Fish WBCs 372
14.20 Fish Thrombocytes 373
14.21 Blood Parasites of Fish 374
14.22 Hematological Testing Techniques for Fish 374
14.23 Anticoagulants for Fish Samples 377
14.24 Summary 377

Section IV Reference Images, Ranges, and Case Studies 381

15 Reference Images 383
15.1 Introduction 383
15.2 Erythrocyte Morphology 384
15.3 Erythrocyte Variation 389
15.4 Red Blood Cell Formation 400
15.5 Red Blood Cell Inclusions 401
15.6 Stain Artifact 403
15.7 Normal White Blood Cells Per Veterinary Species 405
15.8 White Blood Cell Variations 430
15.9 Thrombocyte Morphology 439
15.10 Blood Parasites 444
15.11 Miscellaneous Microscopic Findings 450

16 Clinical Case Presentations 451
16.1 Introduction 451
16.2 Case Study 1: Mindy the Yorkie-Zinc Toxicity and Hemolytic Anemia 452
16.3 Case Study 2: Blinxie the Cat-Renal Lymphoma and Non-regenerative Anemia 455
16.4 Case Study 3: Peter the Collie Mix-Granulocytic Leukemia 458
16.5 Case Study 4: Shelby the Quarter Horse-Piroplasmosis 461
16.6 Case Study 5: Mr. President the Shelter Cat-Hemotropic Mycoplasma 463
16.7 Case Study 6: Valetto the Cat-Feline Retroviruses 466
16.8 Case Study 7: Twinkle the Shetland Sheep-Sepsis and Trauma Response 468
16.9 Case Study 8: Kelsey the Pitbull Mix-Multiple Myeloma and Immune-mediated Thrombocytopenia 470
16.10 Case Study 9: Winston the Horse-Persistent Basophilia 472
16.11 Case Study 10: Travis the Dog-Rodenticide Poisoning 475
16.12 Case Study 11: Mowgli the Dog-Immune-mediated Hemolytic Anemia 477
16.13 Case Study 12: Dot the Cow-Bovine Lymphoma 479
16.14 Summary: Case Studies in Veterinary Hematology 481

17 Reference Ranges for Common Hematological Tests 483
17.1 Introduction 483
17.2 Packed Cell Volume 483
17.3 Hemoglobin 485
17.4 Total RBC Count 485
17.5 Reticulocyte Values 485
17.6 RBC Indices 486
17.7 Platelets 487
17.8 Total WBC Count 488
17.9 WBC Differential and Absolute Values 488
17.10 Total Solids 489
17.11 Fibrinogen 490

References 490
Index 491