Dr.Iman Daham , BSci., MSc., PhD. Assist. Prof., Department of Internal and Preventive Medicine College of Veterinary Medicine, University of Mosul, Mosul, Iraq https://orcid.org/0000-0002-0947-7169 https://www.researchgate.net/profile/Iman Daham Clinical Pathology | Part I | 4th year 2019

Evaluation of White Blood Cells Picture (Leukocytes) I-General The term leukocyte include all white blood cells and their precursors. These cells use blood stream as a means of transport from their site of origin to the site in tissues where they are required . The circulating numbers therefore reflect the balance between supply and demand , and usually rang between about 5-14 ×10/L depending to some extent on species. The leukocytes can be divided in two basic categories: 1-The which include Neutrophils , Eosinophil’s and . 2-Agranulocytes which include Lymphocytes and .

II-Alteration of the Leukocyte picture 1- A-Physiological leukocytosis : a-age of animal: Total leukocyte count are higher in the young than in the adult of Dog and Cattle. Lowered leukocyte count in young animals than in adults appeared in Swine. No significant difference in total leukocyte count of young animal and adults in Horse and Sheep. b-Digestion is accompanied with leukocytosis as in Dog (one hour after digestion that reached its maximum about 3-4 hours and then declines) Horses have a weak digestion leukocytosis. c-Epinephrine injection. d-Pregnancy in cattle induces Leukocytosis with especially two weeks before parturition.

B-Pathological Leukocytosis: a-Acute infection by pyogenic bacteria as 1-Staphilococcus 2-Streptococcus. b-Rabies virus infection induces mild Leukocytosis. c- Noninfectious conditions : 1-Diabetes mellitus 2-Uraemia 3- Acute hemorrhage or hemolysis

2- Reduction in leukocyte count below normal values. Its includes all types of white cells or one type . The general causes of Leukopenia are related to alteration in the bone marrow as : a-Degeneration b-Depression c-Destruction d-Depletion Leukopenia thus occurs in the following : 1-viral infections as canine distemper, mucosal disease, infectious canine hepatitis. 2-Endotoxins from gram negative bacteria. 3-X-rays and radioisotopes through destroying the cellular elements of the bone marrow . 4-Chemical agents as antibiotics(chloramphenicol, penicillin’s, streptomycin), inorganic chemical (lead, benzene, mercury,),antihistaminic and sulphonamides. Clinical pathology I | Lecture title | Dr.Iman Daham Hadi Page | 1

3-Neutrophilia Neutrophils function primarily as Phagocytes. Neutrophilia means an increased number of neutrophils in circulation blood . this can occur in the following: 1-Acute infections a-Generalized: 1-Septicaemia 2- Anthrax b-Localized: 1- Abscesses 2- Osteomyelitis 2-Acute hemolysis 3-Trauma including surgical procedures. 4- Physiological leukocytosis. 5-Granulocytic Leukemia . 6- Malignant lymphoma in canine.

4- Means decreased number of neutrophils in circulating blood . this can occur in the following: 1-Autoimmune neutropenia . 2-Endotoxin injection. 3- At first few hours of acute infection . 4-Decreased bone marrow production. 5-Following anemia and thrombocytopenia .

5- The major function of eosinophil’s is Detoxification by inactivation of histamine or histamine like toxic materials. Eosinophilia means an increase in circulating numbers of eosinophils. Eosinophilia follows: 1-Hypersensitivity a- Parasites especially those that migrate through the tissues such as : 1-Hookworms 2-Strongylosis 3-Cestodes. b-Allergy 1-Allergic bronchitis and sinusitis 2-Allergic dermatitis. 2-Granulocytic leukemia. 3-Recovery phase of some acute infection. 4-Eosinophilic myositis. 5- Adrenocortical insufficiency. 6- Following radiation therapy 2-3 weeks later. 7- Some bone disease especially if necrosis is present.

6- Eosinopenia means an decrease in circulating numbers of eosinophils. The case follows : 1-After administration of Adrenocortical tropic hormone(ACTH)or corticoids as a therapeutic measure. 2-Hyperactivity of adrenal gland following hyperplasia or neoplasia.

7- Basophils are closely related to the tissue mast cells and share to function of releasing histamine Containing granules and thus initiating the inflammatory response.

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Basophilia refers to an increased number of circulating basophils. The case is rare. It occurs in : 1-In association with eosinophilia. 2-Basophilic granulocytic leukemia. 3-In dog with Heartworms.

8-Basopenia It means decreased number of circulating Basophils. Since it is quite normal to find no basophils at all in a blood film the theoretical Possibilities of Basopenia are not worth considering in clinical situation.

9-Lymphocytosis The primary function of Lymphocytes are immunological, in humeral antibody formation and cell Mediated immunity. Lymphocytosis refers to an increased number of circulating Lymphocytes. Lymphocytosis is associated with: 1-Chronic disease usually with only a slight increase in number. 2-Recovery from viral infection. 3-Following vaccination. 4-Hyperthyroidism.

10-Lymphopenia This refers to a decrease number of circulating Lymphocyte. 1-Hyperadrenocorticalism in stress, steroid therapy. 2-Acute viral infection as canine distemper, infectious canine hepatitis and infectious feline enteritis. 3-Neoplasia.

11- The main function of Monocytes and is phagocytosis particularly of large particles such As tissue debris and more difficult pathogens as fungi, protozoa and Brucella spp. Monocytosis refers to an increased number of circulating monocytes. The case follows: 1-Monocytic leukemia. 2-Listeriosis in Swine’s. 3-Brucellosis. 4-Accompany leukopenia and neutropenia. 5-Hyperadrenocorticosism. 6-In association with acute stress reaction in Dog and Cat.

12- Means decreased or complete absence of monocytes in blood stream. 1-Occurs in certain species (cat ,horse, cattle) as a part of acute steroid response. 2-Since it is not uncommon to find no monocytes at all in a blood film from normal animal, thus Interpretation of monocytopenia is of question.

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Regenerative Left Shift: Neutrophils and Leukocytosis accompanied with immature neutrophils. Is manifested by a slight to Moderate increase in the number of the Band Neutrophilia with increase in the absolute number of. Neutrophilia.

Degenerative Lift Shift: Normal or Low total Leukocytes count and Neutropenia. Is manifested by a slight to moderate Increase in the number of the segmented Neutrophilia with increase in the absolute number of Neutrophilia.

Interpretation of Leukocyte alteration : 1-Extent of Leukocytosis indicates the degree of an individual resistance and the degree of left shift Indicate the severity of infection. 2-Appearance of immature Neutrophils instead of mature ones indicates severity of the disease. 3-Neutrophilia and Lymphopenia and Eosinopenia is indicative for a moderately severe to severe condition and reflects stress. 4-High total Leukocyte count , many of Neutrophils is indicative of a more severe condition with Good bone marrow response.

Leukosis(Leukemia) Is a generalized ,Probably neoplastic, Malignant proliferation of one of the Leukocyte Tissues(Bone marrow, Lymphoid tissue, Reticule-endothelial system, and the plasma Cell system).

Leukosis could be Classified according to Duration, Leukocyte count, Stage of maturity and cell type To:- A-According to duration Leukemia is classified as: 1-Acute : a-Usually Sub leukemia. b-Many undifferentiated or immature cells in Bone marrow or blood. 2-Chronic: a-May be Leukemic, Sub Leukemic, A Leukemic. b-Blood count vary during the course of the disease. c-Well defined differentiation to mature type of cells.

B-According to Leukocyte count and stage of cell maturity. : 1-Leukemic : High Leukocyte count . 2-Sub Leukemic: Normal or increase leukocyte counts, but with abnormal differential count, showing primitive cells. 3-A Leukemic: a-Normal leukocyte count and no abnormal or immature cells in the blood smear. b-Usually seen during period of remission in one of the other types .

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C-According to the type of predominating cell observed in the blood smear , bone marrow or lymphoid Tissue. 1-Granulocytic (Myelogenous, Myelocytic or Myeloid Leukemia) i.e. cell type is derived from myeloid tissue: a-Eosinophilic and Basophilic (Mast cell) Leukemia. b-Chloroma a typical acute granulocytic leukemia. 2-Lymphocytic (Lymphatic, Lymphogenous or Lymphoid Leukemia) where blood picture may Represent invasion of the blood by localized tumor cells (Malignant Lymphoma , Lymphomosarcoma Reticular cell sarcoma or plasmocytoma). 3-Monocytic Leukemia associated with reticular cell sarcoma. 4-Plasmocytic Leukemia associated with multiple myeloma.

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