Pathology: Haematology (Cells, Organs, Clotting)
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Questions and Answers

What percentage of an animal's total body weight does blood typically comprise?

  • 1-5%
  • 5-10% (correct)
  • 10-15%
  • 15-20%

    • Erythrocytes are also known as platelets.

    False

    Name the primary source of erythrocytes in adult animals.

    Bone marrow

    The three major cell types present in blood are erythrocytes, leukocytes, and __________.

    <p>platelets</p> Signup and view all the answers

    Match the following blood components with their types:

    <p>Erythrocytes = Red blood cells Leukocytes = White blood cells Platelets = Cell fragments involved in clotting Haemostasis = Process of stopping bleeding</p> Signup and view all the answers

    In which organ does primary haematopoiesis occur during the first half of embryonic life?

    <p>Liver</p> Signup and view all the answers

    Active haematopoiesis in adults is confined to bones such as the ribs and vertebrae.

    <p>True</p> Signup and view all the answers

    What happens to the haematopoietic marrow with maturity in animals?

    <p>It gets replaced with fat and becomes yellow marrow.</p> Signup and view all the answers

    What is the primary function of mature erythrocytes?

    <p>To deliver oxygen to tissues</p> Signup and view all the answers

    The spleen functions as a site for erythrocyte production.

    <p>False</p> Signup and view all the answers

    What hormone do the kidneys produce to stimulate erythropoiesis?

    <p>Erythropoietin (EPO)</p> Signup and view all the answers

    The __________ is responsible for controlling differentiation of bone marrow-derived stem cells into T lymphocytes.

    <p>thymus</p> Signup and view all the answers

    Match the following blood components with their functions:

    <p>Prothrombin = Clotting factor Albumin = Maintains osmotic pressure Fibrinogen = Forms blood clots Erythropoietin = Stimulates erythrocyte production</p> Signup and view all the answers

    Which vitamin is essential for vitamin B12 absorption?

    <p>Intrinsic factor</p> Signup and view all the answers

    Lymph nodes produce only B-lymphocytes.

    <p>False</p> Signup and view all the answers

    Name one mineral essential for erythrocyte production.

    <p>Iron</p> Signup and view all the answers

    Erythropoiesis is the process of __________.

    <p>production of erythrocytes</p> Signup and view all the answers

    Match the following organs with their roles in erythropoiesis:

    <p>Bone Marrow = Production of erythrocytes Kidney = Production of erythropoietin Spleen = Storage of erythrocytes Thymus = Differentiation of T lymphocytes</p> Signup and view all the answers

    What is the primary energy source for mature erythrocytes?

    <p>Glucose</p> Signup and view all the answers

    Reticulocytes are immature erythrocytes that have not yet extruded their nucleus.

    <p>True</p> Signup and view all the answers

    Which cytokine stimulates the differentiation of stem cells into erythrocytes?

    <p>Erythropoietin</p> Signup and view all the answers

    Deficiency in __________ can impair erythropoiesis.

    <p>vitamins, minerals, or proteins</p> Signup and view all the answers

    Match the following functions to the correct blood component:

    <p>Albumin = Transport of substances Hemoglobin = Oxygen transport Fibrinogen = Blood clotting Erythropoietin = Stimulating maturation of erythrocytes</p> Signup and view all the answers

    What does the haematocrit (Hct) measure?

    <p>The volume of erythrocytes compared to whole blood</p> Signup and view all the answers

    An increased mean corpuscular volume (MCV) is called microcytosis.

    <p>False</p> Signup and view all the answers

    What does PCV stand for in a Complete Blood Count?

    <p>Packed Cell Volume</p> Signup and view all the answers

    The unit for mean corpuscular volume (MCV) is __________.

    <p>femtolitre</p> Signup and view all the answers

    Match the terms to their definitions:

    <p>MCV = Average size of RBC PCV = Percentage of erythrocytes in blood MCHC = Hb concentration in RBC volume RBC count = Number of erythrocytes per unit volume</p> Signup and view all the answers

    Which condition is most commonly associated with microcytosis?

    <p>Iron deficiency anaemia</p> Signup and view all the answers

    Reticulocytes are the most mature stage of erythrocytes.

    <p>False</p> Signup and view all the answers

    What is the significance of a high reticulocyte count in an animal?

    <p>Bone marrow response to anemia</p> Signup and view all the answers

    The concentration of hemoglobin per unit volume of red blood cells is known as _________.

    <p>Mean corpuscular hemoglobin concentration (MCHC)</p> Signup and view all the answers

    How is the mean corpuscular volume (MCV) calculated?

    <p>Hct x 10 / RBC count</p> Signup and view all the answers

    Horses typically release reticulocytes from their bone marrow.

    <p>False</p> Signup and view all the answers

    What indicates an artefactual increase in MCHC?

    <p>Haemolysis or erythrocyte shrinkage</p> Signup and view all the answers

    The amount of hemoglobin in grams per litre of blood is known as __________.

    <p>hemoglobin concentration</p> Signup and view all the answers

    What does a reticulocyte appear as in routinely stained blood smears?

    <p>Larger, bluer erythrocytes</p> Signup and view all the answers

    What is the primary function of the hexose monophosphate shunt?

    <p>It protects haemoglobin from oxidation.</p> Signup and view all the answers

    The lifespan of a dog's erythrocytes is approximately 120 days.

    <p>True</p> Signup and view all the answers

    What is the condition called when methaemoglobin cannot transport oxygen due to oxidization of heme iron?

    <p>Methaemoglobinaemia</p> Signup and view all the answers

    _________ results from the breakdown or destruction of erythrocytes.

    <p>Haemolysis</p> Signup and view all the answers

    Match the following terms with their correct definitions:

    <p>Haemoglobinaemia = Presence of hemoglobin in plasma Haemoglobinuria = Hemoglobin in urine Extravascular hemolysis = Destruction of old erythrocytes by macrophages Intravascular hemolysis = Destruction of erythrocytes in the blood stream</p> Signup and view all the answers

    Which pathway allows for the formation of 2,3-DPG?

    <p>2,3 Diphosphoglycerate pathway (Luebering-Rapaport)</p> Signup and view all the answers

    All animals have the same lifespan for their erythrocytes.

    <p>False</p> Signup and view all the answers

    What compound binds to free hemoglobin in plasma after intravascular hemolysis?

    <p>Haptoglobin</p> Signup and view all the answers

    Iron is transported in blood bound to __________.

    <p>transferrin</p> Signup and view all the answers

    An increase in transferrin concentrations may indicate which of the following conditions?

    <p>Haemolytic anaemias</p> Signup and view all the answers

    Bilirubin is produced from the disassembly of hemoglobin after erythrocyte destruction.

    <p>True</p> Signup and view all the answers

    What is the term for the measure of the plasma capacity to carry iron?

    <p>Total iron-binding capacity (TIBC)</p> Signup and view all the answers

    Match the following storage sites with their typical iron content percentages:

    <p>Erythrocytes = 50-70% Macrophages = 25-40% Other molecules = Small amounts Iron storage in liver = Minimal compared to erythrocytes</p> Signup and view all the answers

    What are keratocytes commonly associated with?

    <p>Liver diseases in cats</p> Signup and view all the answers

    Spherocytes are pathognomonic for immune-mediated haemolytic anaemia.

    <p>False</p> Signup and view all the answers

    What are Heinz bodies?

    <p>Clumps of denatured haemoglobin on the internal surface of the erythrocyte membrane.</p> Signup and view all the answers

    Basophilic stippling occurs due to aggregations of __________ in the cytoplasm.

    <p>ribosomes</p> Signup and view all the answers

    Match the following erythrocyte types with their characteristics:

    <p>Keratocytes = Erythrocytes with projections due to vesicles Spherocytes = Spherical cells due to membrane removal Eccentrocytes = Cells with hemoglobin shifted to one side Howell-Jolly bodies = Nuclear remnants within erythrocytes</p> Signup and view all the answers

    In which condition are Howell-Jolly bodies commonly observed?

    <p>Chronic steroid therapy</p> Signup and view all the answers

    Agglutination is characterized by erythrocytes forming stacks like coins.

    <p>False</p> Signup and view all the answers

    What causes the formation of eccentrocytes?

    <p>Oxidative damage to erythrocytes.</p> Signup and view all the answers

    Lead poisoning is highly suggestive if basophilic stippling is seen without __________.

    <p>anaemia</p> Signup and view all the answers

    Match the types of anaemia with their associated causes:

    <p>Regenerative anaemia = Increased RBC production Non-regenerative anaemia = Ineffective erythropoiesis Iron deficiency anaemia = Nutritional deficiency Chronic disease anaemia = Underlying systemic disease</p> Signup and view all the answers

    What feature distinguishes spherocytes from normal erythrocytes?

    <p>They have no central pallor.</p> Signup and view all the answers

    Rouleaux formation is commonly enhanced in animals with hyperfibrinogenemia.

    <p>True</p> Signup and view all the answers

    What condition is indicated by the presence of metarubricytes in the circulation?

    <p>Regenerative response or bone marrow damage.</p> Signup and view all the answers

    Siderocytes contain __________ and stain positively with Prussian blue.

    <p>iron granules</p> Signup and view all the answers

    What is the term for an increase in the PCV, erythrocyte count, or hemoglobin concentration above the normal range?

    <p>Erythrocytosis</p> Signup and view all the answers

    Relative erythrocytosis is associated with a true increase in the total red cell mass.

    <p>False</p> Signup and view all the answers

    What common condition is most often associated with relative erythrocytosis?

    <p>Dehydration</p> Signup and view all the answers

    A significant increase in erythrocyte count due to tissue hypoxia is termed _______ erythrocytosis.

    <p>Secondary</p> Signup and view all the answers

    Which of the following is NOT a cause of inappropriate secondary erythrocytosis?

    <p>High altitude</p> Signup and view all the answers

    Match the type of erythrocytosis with its cause:

    <p>Relative Erythrocytosis = Dehydration Physiologic Erythrocytosis = Splenic contraction Primary Erythrocytosis = Autonomous erythropoiesis Secondary Erythrocytosis = Tissue hypoxia</p> Signup and view all the answers

    Erythrocytosis is often a benign condition that requires no treatment.

    <p>False</p> Signup and view all the answers

    What are the hallmarks of regeneration seen in a blood smear for anaemia?

    <p>Reticulocytes and polychromatophilic erythrocytes</p> Signup and view all the answers

    The clinical signs of anemia may include _______ mucous membranes and increased _______ rate.

    Signup and view all the answers

    What is the primary classification of anaemia based on bone marrow responsiveness?

    <p>Regenerative, Pre-regenerative, Non-regenerative</p> Signup and view all the answers

    Regenerative anaemia is characterized by the bone marrow not responding to the loss of erythrocytes.

    <p>False</p> Signup and view all the answers

    What are reticulocytes an indicator of in the context of regenerative anaemia?

    <p>Increased erythropoiesis</p> Signup and view all the answers

    Microcytic anaemias are almost invariably due to __________ deficiency.

    <p>iron</p> Signup and view all the answers

    Match the type of anaemia with its cause:

    <p>Regenerative anaemia = Haemorrhage or haemolysis Non-regenerative anaemia = Deficiency in erythrocyte production Pre-regenerative anaemia = Insufficient time for a response Microcytic anaemia = Iron deficiency</p> Signup and view all the answers

    What kind of hematological change is observed in the presence of regenerative anaemia?

    <p>Increased reticulocyte count</p> Signup and view all the answers

    Macrocytic anaemia may indicate regeneration in the case of horses.

    <p>True</p> Signup and view all the answers

    What is required for a bone marrow response to be classified as regenerative?

    <p>Blood loss or severe erythrocyte destruction</p> Signup and view all the answers

    A failure to show evidence of regeneration in the face of anaemia suggests __________ anaemia.

    <p>non-regenerative</p> Signup and view all the answers

    Match the erythrocyte patterns with their significance:

    <p>Normocytic normochromic = 'Normal' erythrocytes Macrocytic, hypochromic = Suggests regenerative anaemia Microcytic, hypochromic = Indicates iron deficiency Microcytic normochromic = Early iron deficiency or hepatic disease</p> Signup and view all the answers

    What laboratory test may indicate the nature of regenerative anaemia?

    <p>Estimation of plasma protein</p> Signup and view all the answers

    An artefactually increased MCV may occur in immune-mediated haemolytic anaemia.

    <p>True</p> Signup and view all the answers

    What common cause of iron deficiency anaemia should be checked in animals with microcytic anaemia?

    <p>Chronic blood loss from gastrointestinal disease</p> Signup and view all the answers

    Pre-regenerative anaemias reflect that __________ hasn't elapsed for a regenerative response.

    <p>sufficient time</p> Signup and view all the answers

    Which of the following signals the bone marrow to initiate erythropoiesis?

    <p>Decrease in red cell mass</p> Signup and view all the answers

    What is the timeframe in which reticulocytosis typically becomes apparent after a hemorrhagic episode?

    <p>3-5 days</p> Signup and view all the answers

    Haemolytic anaemia occurs when erythrocyte destruction is balanced by increased erythropoiesis.

    <p>False</p> Signup and view all the answers

    What is a common cause of chronic blood loss in animals?

    <p>Internal parasitism</p> Signup and view all the answers

    Acute blood loss can lead to hypovolaemic shock if the blood volume is reduced to ______% of normal.

    <p>60-70</p> Signup and view all the answers

    Match the following conditions with their associated characteristics:

    <p>Acute Blood Loss = Rapid drop in PCV, RBC count, and hemoglobin Chronic Blood Loss = Gradual anemia with evidence of regenerative response Haemolytic Anaemia = Increased reticulocyte counts and normal plasma protein concentration Intravascular Haemolysis = Escape of hemoglobin into plasma</p> Signup and view all the answers

    What is a potential laboratory result seen in intravascular haemolysis?

    <p>Haemoglobinaemia</p> Signup and view all the answers

    The plasma protein concentration typically decreases in cases of chronic blood loss.

    <p>False</p> Signup and view all the answers

    Which hallmarks are indicative of regenerative anaemia on a blood smear?

    <p>Polychromasia and anisocytosis</p> Signup and view all the answers

    What happens to erythrocyte parameters within 10-14 days following a single hemorrhagic episode?

    <p>They return to normal.</p> Signup and view all the answers

    Anisocytosis refers to the uniform size of erythrocytes.

    <p>False</p> Signup and view all the answers

    What is the primary assessment used to determine thrombocyte (platelet) count in a CBC?

    <p>Platelet count</p> Signup and view all the answers

    After severe blood loss, platelet numbers may ______ during the first few hours.

    <p>increase</p> Signup and view all the answers

    Which of the following is NOT a common cause of acute blood loss?

    <p>Internal parasitism</p> Signup and view all the answers

    The diameter of a dog’s erythrocyte is approximately ______ μm.

    <p>7</p> Signup and view all the answers

    Reticulocyte counts are usually lower in haemolytic anaemia compared to haemorrhagic anaemia.

    <p>False</p> Signup and view all the answers

    Match the following erythrocyte shapes with their descriptions:

    <p>Spherocytes = Abnormally rounded cells with a decreased surface area Schistocytes = Fragmented erythrocytes due to trauma Acanthocytes = Cells with irregular surface projections Echinocytes = Crenated cells caused by drying artifacts</p> Signup and view all the answers

    What does hypochromic mean in the context of chronic blood loss?

    <p>Reduced hemoglobin concentration in erythrocytes.</p> Signup and view all the answers

    What does hypochromasia indicate about erythrocytes?

    <p>Decreased haemoglobin content</p> Signup and view all the answers

    The condition in which the erythrocyte membrane is damaged leading to haemoglobin spilling into the serum is known as ______ haemolysis.

    <p>intravascular</p> Signup and view all the answers

    Polychromatophils are immature erythrocytes containing ribosomes and mitochondria.

    <p>True</p> Signup and view all the answers

    What is the term for variation in color among erythrocytes?

    <p>Polychromasia</p> Signup and view all the answers

    Match the following types of haemolysis with their descriptions:

    <p>Intravascular = Occurs within blood vessels, leads to haemoglobinaemia Extravascular = Accelerated removal of erythrocytes by macrophages Haemolytic Response = Presence of reticulocytosis Regenerative Response = Increased RBC production in response to anemia</p> Signup and view all the answers

    The general term for any abnormally shaped erythrocytes is ______.

    <p>poikilocytosis</p> Signup and view all the answers

    Which RBC morphological abnormality is associated with liver disease in dogs?

    <p>Acanthocytes</p> Signup and view all the answers

    Bone marrow aspirate is indicated in all patient cases.

    <p>False</p> Signup and view all the answers

    What type of stain would be used to identify reticulocytes?

    <p>Supra vital stain</p> Signup and view all the answers

    Microcytosis refers to the presence of ______ erythrocytes.

    <p>smaller</p> Signup and view all the answers

    The central pallor in normal erythrocytes indicates what?

    <p>Decreased hemoglobin content</p> Signup and view all the answers

    What causes reduced erythrocyte deformability?

    <p>Impaired glycolysis</p> Signup and view all the answers

    Splenomegaly is a common feature of extravascular hemolysis.

    <p>True</p> Signup and view all the answers

    What is the main character of immune-mediated hemolytic anemia (IMHA)?

    <p>Accelerated erythrocyte destruction due to an immunological reaction.</p> Signup and view all the answers

    The Coomb's test is used to determine the presence of __________ in the blood.

    <p>autoagglutination</p> Signup and view all the answers

    Match the following features with their associated conditions:

    <p>Spherocytes = Immune-Mediated Hemolytic Anemia Positive Coomb's test = Autoagglutination of RBCs Neutrophilia = IMHA with left shift Haemoglobinuria = Severe acute anemia</p> Signup and view all the answers

    Which condition is commonly associated with neonatal isoerythrolysis?

    <p>Incompatibility of RBC antigens between foal and mare</p> Signup and view all the answers

    Neonatal isoerythrolysis rarely occurs in foals born to maiden mares.

    <p>True</p> Signup and view all the answers

    What test is used before foals are allowed to feed to predict neonatal isoerythrolysis?

    <p>A screening test using umbilical cord blood against mare’s colostrum.</p> Signup and view all the answers

    Neonatal isoerythrolysis is often confirmed by demonstrating maternal antibodies on the foal’s __________.

    <p>erythrocytes</p> Signup and view all the answers

    Which of the following is a possible outcome for affected foals with neonatal isoerythrolysis?

    <p>Weakness and lethargy within 24-48 hours</p> Signup and view all the answers

    Haemoglobinuria can occur in severe cases of immune-mediated hemolytic anemia.

    <p>True</p> Signup and view all the answers

    What is the main treatment approach for dogs with immune-mediated hemolytic anemia?

    <p>Corticosteroid therapy.</p> Signup and view all the answers

    The __________ destruction of erythrocytes in IMHA can lead to a marked regenerative response.

    <p>accelerated</p> Signup and view all the answers

    Which species commonly experiences immune-mediated hemolytic anemia?

    <p>Dogs</p> Signup and view all the answers

    Neoplasia can trigger immune-mediated hemolytic anemia.

    <p>True</p> Signup and view all the answers

    What is a common consequence of neonatal isoerythrolysis in horses?

    <p>Incompatible matings</p> Signup and view all the answers

    Iron deficiency anemia is primarily caused by excess iron in the diet.

    <p>False</p> Signup and view all the answers

    Name one species that can experience neonatal isoerythrolysis aside from horses.

    <p>Humans</p> Signup and view all the answers

    Newborn piglets require ______ supplementation to prevent iron deficiency anemia.

    <p>iron</p> Signup and view all the answers

    Match the following conditions with their associated species:

    <p>Neonatal isoerythrolysis = Horses Iron deficiency anemia = Pigs Sporidesmin toxicity = Cattle Chronic copper toxicity = Sheep</p> Signup and view all the answers

    What is a hallmark feature of iron deficiency anemia?

    <p>Microcytosis</p> Signup and view all the answers

    Heinz bodies are a common feature in chronic copper toxicity.

    <p>True</p> Signup and view all the answers

    What is the primary cause of iron deficiency anemia in newborn animals?

    <p>Chronic blood loss</p> Signup and view all the answers

    Haemolytic anemia in calves can be caused by L.______ infection.

    <p>pomona</p> Signup and view all the answers

    Match the organism to the condition it causes:

    <p>Mycoplasma haemofelis = Haemolytic anemia in cats Mycoplasma ovis = Not clinically significant Eperythrozoon suis = Clinical problems in pigs Leptospira pomona = Haemolytic anemia in calves</p> Signup and view all the answers

    What is a significant outcome of acute sporidesmin toxicity in cattle?

    <p>Intravascular haemolysis</p> Signup and view all the answers

    Blood parasites are common in domestic animals in New Zealand.

    <p>False</p> Signup and view all the answers

    What is one consequence of copper accumulation in sheep's liver?

    <p>Acute intravascular haemolysis</p> Signup and view all the answers

    In iron deficiency anemia, red cells may appear ______ and ______ under a microscope.

    <p>microcytic, hypochromic</p> Signup and view all the answers

    What is eosinophilia primarily characterized by?

    <p>Increased number of eosinophils</p> Signup and view all the answers

    Neutrophils are primarily involved in antibody production.

    <p>False</p> Signup and view all the answers

    What are the main pools of neutrophils in the bone marrow?

    <p>Dividing pool, maturation pool, storage pool</p> Signup and view all the answers

    The process by which white blood cells are produced is called __________.

    <p>leukopoiesis</p> Signup and view all the answers

    Match the types of leukocytes with their primary functions:

    <p>Neutrophils = Phagocytosis of bacteria Lymphocytes = Antibody production Monocytes = Maturation into macrophages Eosinophils = Combat parasites</p> Signup and view all the answers

    What characterizes a corticosteroid response in leukograms?

    <p>Increase in neutrophils and decrease in lymphocytes</p> Signup and view all the answers

    Phagocytosis is a process unique to neutrophils.

    <p>False</p> Signup and view all the answers

    What is the role of opsonization in phagocytosis?

    <p>To enhance the recognition and engulfment of pathogens by leukocytes.</p> Signup and view all the answers

    The second most common type of leukocyte is __________.

    <p>lymphocyte</p> Signup and view all the answers

    Eosinopenia may be caused by which of the following conditions?

    <p>Corticosteroid treatment</p> Signup and view all the answers

    Heterophils lack some oxidative pathways that neutrophils use to kill microbes.

    <p>True</p> Signup and view all the answers

    What is the significance of a left shift in a blood smear?

    <p>It indicates an increased demand for neutrophils, showing immature forms in circulation.</p> Signup and view all the answers

    The process of producing granulocytes in the bone marrow is known as __________.

    <p>granulopoiesis</p> Signup and view all the answers

    Match the leukocyte types with their characteristics:

    <p>Neutrophils = Multi-lobed nucleus, phagocytic Eosinophils = Bilobed nucleus, combat parasites Basophils = Contain histamine granules Monocytes = Kidney-shaped nucleus, become macrophages</p> Signup and view all the answers

    What is the most common non-regenerative anaemia seen in animals?

    <p>Anaemia of chronic disease</p> Signup and view all the answers

    Anaemia due to chronic renal disease often results from increased erythropoietin production by the kidneys.

    <p>False</p> Signup and view all the answers

    What parasite is associated with Theileria associated bovine anaemia (TABA)?

    <p>Theileria orientalis</p> Signup and view all the answers

    What feature is characteristic of iron deficiency anemia?

    <p>Microcytosis</p> Signup and view all the answers

    Cattle infected with Theileria orientalis show clinical disease throughout their life.

    <p>False</p> Signup and view all the answers

    What is the preferred method for diagnosing Theileria orientalis?

    <p>PCR</p> Signup and view all the answers

    Dogs with __________ commonly have a mild, normocytic, non-regenerative anaemia.

    <p>hypothyroidism</p> Signup and view all the answers

    Match the following types of anaemia with their causes:

    <p>Iron deficiency anaemia = Chronic blood loss Lead toxicity = Inhibition of heme synthesis Anaemia of chronic renal disease = Decreased erythropoietin production Taranaki anaemia = Magnesium deficiency</p> Signup and view all the answers

    Brassica crops can cause haemolytic anaemia due to the presence of __________.

    <p>S-methylcysteine sulphoxide</p> Signup and view all the answers

    What is a common feature observed in iron deficiency anemia?

    <p>Presence of 'blister cells'</p> Signup and view all the answers

    Match the following conditions with their causes:

    <p>Theileria orientalis = Haemolytic anaemia Brassica poisoning = S-methylcysteine sulphoxide Aplastic anaemia = Drug toxicity Post-Parturient Haemoglobinuria = Phosphorus deficiency</p> Signup and view all the answers

    Thrombocytosis is present in approximately 50% of animals with iron deficiency.

    <p>True</p> Signup and view all the answers

    Which of the following is a common factor influencing the severity of TABA?

    <p>Environmental conditions</p> Signup and view all the answers

    What type of anaemia is often mild to severe due to chronic renal failure?

    <p>Normocytic-normochromic non-regenerative anaemia</p> Signup and view all the answers

    Panfcytopenia indicates normal levels of red, white, and platelet cell lines.

    <p>False</p> Signup and view all the answers

    What characteristic is associated with Bovine Post-Parturient Haemoglobinuria (PPH)?

    <p>Intravascular haemolysis</p> Signup and view all the answers

    The hallmark of iron deficiency anaemia is __________.

    <p>microcytosis</p> Signup and view all the answers

    What is a distinctive feature of lead toxicity-related anaemia?

    <p>Basophilic stippling of erythrocytes</p> Signup and view all the answers

    The cause of copper toxicity leading to accelerated erythrocyte destruction is __________.

    <p>chronic</p> Signup and view all the answers

    Anaemia due to nutrient deficiencies is common and includes deficiencies in vitamins and minerals.

    <p>False</p> Signup and view all the answers

    What is the incubation period for Theileria orientalis in cattle?

    <p>4-6 weeks</p> Signup and view all the answers

    Define the type of anaemia that occurs with chronic udder oedema in dairy cows.

    <p>Taranaki anaemia</p> Signup and view all the answers

    Eperythrozoon spp. are classified as intracellular parasites.

    <p>False</p> Signup and view all the answers

    Name one condition that can cause aplastic anaemia.

    <p>Drug toxicity</p> Signup and view all the answers

    Anaemia of __________ disease can occur without clinical evidence of inflammation.

    <p>chronic</p> Signup and view all the answers

    Match the endocrine disorders to their anaemia characteristics:

    <p>Hypothyroidism = Mild normocytic, non-regenerative Hypoadrenocorticism = Mild normocytic Chronic renal failure = Normocytic-normochromic, non-regenerative Lead toxicity = Mild non-regenerative or poorly regenerative</p> Signup and view all the answers

    The toxic principle in onion poisoning is __________.

    <p>n-propyl disulphide</p> Signup and view all the answers

    Which type of anaemia is characterized exclusively by inadequate erythrocyte production?

    <p>Non-regenerative anaemia</p> Signup and view all the answers

    Match the blood parasites with their corresponding effects or diseases:

    <p>Leptospira pomona = Infects calves, lambs, deer Babesia spp. = Associated with malaria-like symptoms Eperythrozoon spp. = Attaches to red cell membranes Anaplasma spp. = Causes hemolytic anemia</p> Signup and view all the answers

    What is the primary function of B-lymphocytes?

    <p>Producing large quantities of antibodies</p> Signup and view all the answers

    Lymphoblasts are immature lymphocytes with a distinct nucleolus.

    <p>True</p> Signup and view all the answers

    What are the main sites of lymphocyte production during foetal development?

    <p>Thymus and gut-associated lymphoid tissues</p> Signup and view all the answers

    _________ is characterized by a marked increase in circulating lymphocytes.

    <p>Lymphocytosis</p> Signup and view all the answers

    Match the types of lymphocytes with their functions:

    <p>B-lymphocytes = Involved in antibody production T-lymphocytes = Cytotoxic and regulatory functions Large granular lymphocytes (LGL) = Presence of magenta granules Lymphoblasts = Immature lymphocytes</p> Signup and view all the answers

    What could potentially cause lymphopenia?

    <p>Decreased production due to radiation therapy</p> Signup and view all the answers

    Reactive lymphocytes often have nucleoli and are irregularly shaped.

    <p>False</p> Signup and view all the answers

    What are lymphokines, and which lymphocytes produce them?

    <p>Lymphokines are mediators of cell-mediated immunity produced by activated T-lymphocytes.</p> Signup and view all the answers

    Lymphoid leukaemia is associated with the presence of circulating __________ lymphocytes.

    <p>neoplastic</p> Signup and view all the answers

    Lymphocytes account for more than 50% of the total leukocyte population in healthy animals.

    <p>False</p> Signup and view all the answers

    What is neutrophilia?

    <p>Increase in neutrophil count</p> Signup and view all the answers

    Cats have a smaller marginal neutrophil pool compared to circulating neutrophil pool.

    <p>False</p> Signup and view all the answers

    What is a common response of the bone marrow when the demand for neutrophils increases?

    <p>Release of stored mature neutrophils and production of new neutrophils.</p> Signup and view all the answers

    The ________ neutrophil pool consists of neutrophils loosely adhered to the vascular endothelium.

    <p>marginal</p> Signup and view all the answers

    Match the types of neutrophilia with their descriptions:

    <p>Physiological neutrophilia = Adrenaline mediated response Corticosteroid neutrophilia = Increased survival time of neutrophils Neutrophilia of inflammatory disease = Release of mature and immature neutrophils Left shift = Presence of immature neutrophils in circulation</p> Signup and view all the answers

    Which statement about neutrophil lifespan is true?

    <p>Neutrophils can remain in blood for an average of only 10 hours.</p> Signup and view all the answers

    Stress neutrophilia can occur without the release of immature neutrophils.

    <p>True</p> Signup and view all the answers

    What is indicated by a left shift in blood neutrophil counts?

    <p>The presence of immature neutrophils due to increased demand.</p> Signup and view all the answers

    In inflammatory diseases, the body may experience neutrophilia accompanied by a left ________.

    <p>shift</p> Signup and view all the answers

    Which animal typically has a larger storage pool of mature neutrophils?

    <p>Dogs</p> Signup and view all the answers

    You would expect to see myeloblasts in circulation during severe inflammation.

    <p>False</p> Signup and view all the answers

    Match the following species to their neutrophil response:

    <p>Dogs = Up to 35 x 10^9/L neutrophilia Cats = Up to 30 x 10^9/L neutrophilia Horses = Up to 20 x 10^9/L neutrophilia Cattle = Up to 20 x 10^9/L neutrophilia</p> Signup and view all the answers

    What does the term 'physiological neutrophilia' refer to?

    <p>An adrenaline-mediated response causing mobilization of neutrophils from the marginal pool.</p> Signup and view all the answers

    Neutrophils are replaced approximately _______ times each day.

    <p>2.5</p> Signup and view all the answers

    What happens when there is not enough mature neutrophils in the storage pool?

    <p>The bone marrow may release immature neutrophils.</p> Signup and view all the answers

    What does the presence of immature neutrophils in circulation indicate?

    <p>Inadequate bone marrow response</p> Signup and view all the answers

    Neutropenia is more frequently seen in dogs and cats than in large animals like horses or cows.

    <p>False</p> Signup and view all the answers

    Name a common cause of increased neutrophil use.

    <p>Inflammation</p> Signup and view all the answers

    Neutrophilia can result from a significant inflammatory response to __________ organisms.

    <p>pyogenic</p> Signup and view all the answers

    Match the following conditions with their effects on neutrophils:

    <p>Acute inflammation = Increased neutrophil demand Pyometra = Marked left shift IMHA = Misinterpreted inflammatory response Sequestration = Transient neutropenia</p> Signup and view all the answers

    Which statement is true regarding toxic changes in neutrophils?

    <p>It reflects accelerated maturation due to demand.</p> Signup and view all the answers

    Neutropenia can lead to an increased risk of infection.

    <p>True</p> Signup and view all the answers

    What does a marked left shift typically indicate?

    <p>Infection or inflammation</p> Signup and view all the answers

    The condition known as __________ is caused by antibodies binding to neutrophils, leading to their destruction.

    <p>immune mediated neutropenia</p> Signup and view all the answers

    Match the following types of leukocyte changes with their descriptions:

    <p>Döhle bodies = Cytoplasmic inclusions seen in toxic change Cytoplasmic basophilia = Higher organelle content leading to blue cytoplasm Immature neutrophils = Indicators of inadequate neutrophil production Myelocytes = Rarely seen in circulation during inflammation</p> Signup and view all the answers

    What is the main cause of neutropenia seen in large animals compared to dogs and cats?

    <p>Smaller storage pool of neutrophils</p> Signup and view all the answers

    Neutropenia can only be caused by decreased production of neutrophils.

    <p>False</p> Signup and view all the answers

    What role do metamyelocytes play in the inflammatory response?

    <p>They are immature neutrophils released during severe inflammation.</p> Signup and view all the answers

    Sequestration of neutrophils is often observed in conditions like __________ shock.

    <p>anaphylactic</p> Signup and view all the answers

    What does erythrocytosis indicate?

    <p>An increase in red blood cell mass</p> Signup and view all the answers

    Relative erythrocytosis is primarily caused by an increase in the total red cell mass.

    <p>False</p> Signup and view all the answers

    What is the primary hormone responsible for stimulating erythrocyte production?

    <p>Erythropoietin</p> Signup and view all the answers

    A decrease in plasma volume due to dehydration can lead to __________ erythrocytosis.

    <p>relative</p> Signup and view all the answers

    Match the types of erythrocytosis with their descriptions:

    <p>Primary Erythrocytosis = Increase in red cell mass without increased EPO levels Secondary Erythrocytosis = Increased red cell mass in response to increased EPO Physiologic Erythrocytosis = Temporary increase due to splenic contraction Relative Erythrocytosis = Normal red cell mass with decreased plasma volume</p> Signup and view all the answers

    Which of the following is the least common cause of inappropriate secondary erythrocytosis?

    <p>Hepatoma</p> Signup and view all the answers

    Erythrocytosis has no known link to splenic contraction.

    <p>False</p> Signup and view all the answers

    Identify two common clinical signs of anemia.

    <p>Pale mucous membranes, lethargy</p> Signup and view all the answers

    Anaemia is characterized by a reduction in __________ count.

    <p>erythrocyte</p> Signup and view all the answers

    What primarily distinguishes absolute erythrocytosis from relative erythrocytosis?

    <p>Total red cell mass</p> Signup and view all the answers

    The hallmark of regeneration in a blood smear is the presence of reticulocytes.

    <p>True</p> Signup and view all the answers

    List one physiological condition that can lead to mild erythrocytosis.

    <p>High altitude</p> Signup and view all the answers

    Inappropriate secondary erythrocytosis can occur due to __________ neoplasms.

    <p>renal</p> Signup and view all the answers

    Match the following causes of regenerative anemia with their descriptions:

    <p>Acute blood loss = Immediate decrease in erythrocyte count due to hemorrhage Hemolytic anemia = Increased destruction of erythrocytes Bone marrow response = Increased production of erythrocytes in response to loss Chronic disease = Sustained reduction in erythrocyte production</p> Signup and view all the answers

    What is the primary function of macrophages derived from monocytes?

    <p>Phagocytosis and removing debris</p> Signup and view all the answers

    Monocytes are referred to as macrophages when they are circulating in the blood.

    <p>False</p> Signup and view all the answers

    Name one location where tissue macrophages can be found.

    <p>Liver, spleen, lungs, lymph nodes, bone, brain</p> Signup and view all the answers

    Monocytosis is an increase in the number of monocytes in blood due to __________.

    <p>inflammation</p> Signup and view all the answers

    Match the types of macrophages with their locations:

    <p>Kupffer cells = Liver Microglial cells = CNS Pulmonary alveolar macrophages = Lungs Osteoclasts = Bone</p> Signup and view all the answers

    What is the nature of the response of monocytes to inflammation?

    <p>Similar but slower than neutrophils</p> Signup and view all the answers

    Monocytes and macrophages are considered distinct cell types.

    <p>False</p> Signup and view all the answers

    The nuclei of mature monocytes can range from __________ to highly-indented.

    <p>oval, bean, horseshoe</p> Signup and view all the answers

    What is the primary effect of corticosteroids in dogs and occasionally in cats?

    <p>Monocytosis</p> Signup and view all the answers

    Eosinopenia is considered clinically significant in most healthy animals.

    <p>False</p> Signup and view all the answers

    Name one common cause of eosinophilia.

    <p>Flea allergy dermatitis</p> Signup and view all the answers

    Eosinophils are predominantly involved in __________ reactions and defense against __________.

    <p>allergic, parasites</p> Signup and view all the answers

    Match the following leukocyte responses with their characteristics:

    <p>Monocytosis = Increase in monocytes Eosinophilia = Increase in eosinophils Neutrophilia = Increase in neutrophils Lymphopenia = Decrease in lymphocytes</p> Signup and view all the answers

    Which species typically has a characteristic rasp-like appearance of eosinophils?

    <p>Horses</p> Signup and view all the answers

    Eosinopenia is commonly caused by an increase in corticosteroids.

    <p>True</p> Signup and view all the answers

    What does the acronym 'SMILED' represent in the context of a stress leukogram?

    <p>Segmented neuts &amp; Monocytes Increased, Lymphocytes &amp; Eosinophils Decreased</p> Signup and view all the answers

    Basophils have variable numbers of lavender to __________ staining granules.

    <p>purple</p> Signup and view all the answers

    Match the following leukocyte disorders with their descriptions:

    <p>Eosinophilia = Increase in eosinophils due to various causes Monocytopenia = Decrease in monocytes, typically not significant Basophilia = Rarely seen increase in basophils Corticosteroid-induced leukogram = Response characterized by mature neutrophilia</p> Signup and view all the answers

    Which of the following is a common manifestation of a stress leukogram?

    <p>Neutrophilia</p> Signup and view all the answers

    Animals with hypoadrenocorticism usually present with a stress leukogram.

    <p>False</p> Signup and view all the answers

    What is a common characteristic of eosinophils in ruminants?

    <p>Numerous small, uniform, round granules</p> Signup and view all the answers

    The most common cause of eosinopenia is __________.

    <p>corticosteroids</p> Signup and view all the answers

    What is the most common form of feline lymphoma?

    <p>Alimentary lymphoma</p> Signup and view all the answers

    What characterizes Acute Lymphoblastic Leukaemia (ALL)?

    <p>Presence of large, immature lymphoblasts</p> Signup and view all the answers

    Thrombocytopenia can be caused by increased platelet production.

    <p>False</p> Signup and view all the answers

    Lymphoma is a benign tumor of lymphoid tissue.

    <p>False</p> Signup and view all the answers

    What are common presenting signs of sporadic lymphoma in cats?

    <p>Weight loss, diarrhoea, vomiting, anorexia.</p> Signup and view all the answers

    The __________ lymphoma form is associated with the feline leukaemia virus.

    <p>retrovirus associated</p> Signup and view all the answers

    What is the typical average survival time for patients with Chronic Lymphocytic Leukaemia (CLL) when treated?

    <p>450 days</p> Signup and view all the answers

    The presence of _____ cells in lymph node aspirates is often a red flag for malignancy.

    <p>epithelial</p> Signup and view all the answers

    Match the following types of lymphoma with their descriptions:

    <p>Sporadic lymphoma = Most common form in cats, affecting older cats Thymic lymphoma = Often displaces heart and lungs Multicentric lymphoma = Affects multiple lymph nodes Alimentary lymphoma = Affects the gastrointestinal tract</p> Signup and view all the answers

    Match the types of lymphatic disorders to their description:

    <p>Lymphoma = Solid tissue neoplastic masses Lymphoid leukaemia = Neoplastic lymphocytes in bone marrow and blood Chronic Lymphocytic Leukaemia = Small, well-differentiated lymphocytes Acute Lymphoblastic Leukaemia = Large, immature lymphoid cells</p> Signup and view all the answers

    Which condition is characterized by an increase in circulating platelet numbers?

    <p>Thrombocytosis</p> Signup and view all the answers

    Which of the following statements about lymphocytosis is true?

    <p>It can occur due to recent vaccinations.</p> Signup and view all the answers

    How is Buccal Mucosal Bleeding Time (BMBT) determined?

    <p>By making a small incision in the buccal mucosa and measuring the time taken for bleeding to stop.</p> Signup and view all the answers

    Bone marrow invasion can occur with lymphomas in cats.

    <p>True</p> Signup and view all the answers

    Chronic Lymphocytic Leukaemia (CLL) usually involves large, immature lymphocytes.

    <p>False</p> Signup and view all the answers

    What is myelopthisis?

    <p>Replacement of the bone marrow by malignant blast cells</p> Signup and view all the answers

    Concurrent non-regenerative __________ is common in feline lymphoma.

    <p>anaemia</p> Signup and view all the answers

    Which breed of dog is known to frequently exhibit artefactual thrombocytopenia due to large platelets?

    <p>Cavalier King Charles Spaniel</p> Signup and view all the answers

    Lymphoproliferative neoplasms arise from _____ or plasma cells.

    <p>lymphocytes</p> Signup and view all the answers

    Match the types of leukaemias with their characteristics:

    <p>Acute Lymphoblastic Leukaemia = Presence of large lymphoblasts Chronic Lymphocytic Leukaemia = Presence of small, mature lymphocytes</p> Signup and view all the answers

    What complication can arise from increased platelet destruction?

    <p>Thrombocytopenia.</p> Signup and view all the answers

    In cats, lymphomas are typically identified in the __________, lymph nodes, and other organs.

    <p>gastrointestinal tract</p> Signup and view all the answers

    Which site is most commonly associated with metastatic spread of carcinomas?

    <p>Lymph nodes</p> Signup and view all the answers

    FeLV and FIV infections have no relation to the development of lymphoma in cats.

    <p>False</p> Signup and view all the answers

    Lymphoma can occur without leukaemia involvement.

    <p>True</p> Signup and view all the answers

    Match the following signs or characteristics with their corresponding type of thrombocytopenia:

    <p>Decreased platelet production = Bone marrow damage or dysfunction Increased platelet consumption = Occurs during surgeries or trauma Increased platelet destruction = Immune-mediated causes Platelet sequestration = Spleen-related issues</p> Signup and view all the answers

    What involves an increased number of large blast forms in the blood?

    <p>Acute Lymphoblastic Leukaemia (ALL)</p> Signup and view all the answers

    Tumour cells may eventually replace the entire _____ during metastatic spread.

    <p>lymph node</p> Signup and view all the answers

    Which factor is involved in the activation of factor X in the intrinsic pathway?

    <p>Factor IX</p> Signup and view all the answers

    The extrinsic pathway is activated by the release of tissue factor from damaged cells.

    <p>True</p> Signup and view all the answers

    What is the role of calcium in the coagulation process?

    <p>Calcium acts as a bridge between coagulation factors and is essential for clotting.</p> Signup and view all the answers

    The common pathway of coagulation begins with the activation of factor _______.

    <p>X</p> Signup and view all the answers

    Match the following coagulation tests with their primary functions:

    <p>PT = Measures fibrin clot formation in the extrinsic/common pathways APTT = Measures fibrin clot formation in the intrinsic/common pathways TT = Measures fibrinogen concentration ACT = Measures fibrin clot formation in fresh whole blood</p> Signup and view all the answers

    Which factor deficiency is most commonly associated with Hemophilia A?

    <p>Factor VIII</p> Signup and view all the answers

    Activated Coagulation Time (ACT) is performed using citrated plasma.

    <p>False</p> Signup and view all the answers

    What are potential symptoms of disorders of secondary haemostasis?

    <p>Large haemorrhages into body cavities and organs.</p> Signup and view all the answers

    Prolonged _______ indicates a defect in the intrinsic or common pathways.

    <p>APTT</p> Signup and view all the answers

    Match the following pathways with their associated activators:

    <p>Intrinsic Pathway = Contact with negatively charged surfaces Extrinsic Pathway = Release of tissue factor III Common Pathway = Activation of factor X Secondary Haemostasis = Involves multiple clotting factors</p> Signup and view all the answers

    Which vitamin is necessary for the activation of factors II, VII, IX, and X?

    <p>Vitamin K</p> Signup and view all the answers

    Factor XI deficiency is a common deficiency that affects coagulation.

    <p>False</p> Signup and view all the answers

    Why is correct sample handling important in coagulation testing?

    <p>To achieve meaningful and accurate results by avoiding clotted or haemolysed samples.</p> Signup and view all the answers

    Vitamin K deficiency can lead to issues with _______ pathway activation.

    <p>extrinsic and intrinsic</p> Signup and view all the answers

    What is the primary cause of recurrent infections in Canine cyclic neutropenia?

    <p>Cyclic decrease in haematopoiesis</p> Signup and view all the answers

    Pelger Huet anomaly results in segmented neutrophils.

    <p>False</p> Signup and view all the answers

    Name one clinical sign associated with Canine Leukocyte Adhesion Deficiency (CLAD).

    <p>Gingivitis</p> Signup and view all the answers

    Thrombocytes are also known as ________.

    <p>platelets</p> Signup and view all the answers

    Match the following conditions with their notable features:

    <p>Canine cyclic neutropenia = Recurrent infections with fluctuating neutrophil counts Pelger Huet anomaly = Hypo-segmented neutrophils Canine Leukocyte Adhesion Deficiency = Severe neutrophilia leading to early death Hereditary neutropenia in Border Collies = Persistent neutropenia and lytic bone lesions</p> Signup and view all the answers

    What stimulates the differentiation of pluripotent haematopoietic stem cells into megakaryocytes?

    <p>Thrombopoietin</p> Signup and view all the answers

    Platelets have a lifespan of about 20-30 days in circulation.

    <p>False</p> Signup and view all the answers

    What are megakaryocytes responsible for producing?

    <p>Platelets</p> Signup and view all the answers

    The condition characterized by excessive production of platelets is called ________.

    <p>thrombocytosis</p> Signup and view all the answers

    Match the following leukocyte inclusions with their associated conditions:

    <p>Chediak-Higashi syndrome = Blue-smoke Persian cats Mucopolysaccharidosis = Various dog and cat breeds Hereditary anomaly of neutrophil granulation = Birman cats Distemper virus infection = Pale blue to purple/red inclusions in neutrophils</p> Signup and view all the answers

    Which breed is commonly associated with a suspected inherited defect in defense mechanisms?

    <p>Weimaraner dogs</p> Signup and view all the answers

    Old platelets in circulation are removed by macrophages in the kidneys.

    <p>False</p> Signup and view all the answers

    What is the primary function of platelets?

    <p>Hemostasis</p> Signup and view all the answers

    Marked leukocytoses can be seen in association with some ________.

    <p>neoplasms</p> Signup and view all the answers

    Match the following dog breeds with their associated disorders:

    <p>Irish red and white setters = Canine Leukocyte Adhesion Deficiency Grey Collie dogs = Canine cyclic neutropenia Weimaraner dogs = Recurrent infections Border Collies = Hereditary neutropenia</p> Signup and view all the answers

    What is the main consequence of Vitamin K remaining inactive in coagulation?

    <p>Inability to activate coagulation factors</p> Signup and view all the answers

    Bleeding typically occurs earlier than 3 days after exposure to rat bait toxicity.

    <p>False</p> Signup and view all the answers

    List two factors that can increase rat bait toxicity.

    <p>High fat diet, drugs that inhibit haemostasis</p> Signup and view all the answers

    Vitamin K-dependent factors such as factor II, VII, IX, and X depend on __________ for activation.

    <p>Vitamin K</p> Signup and view all the answers

    Match the following conditions with their potential laboratory findings:

    <p>DIC = Increased PT and APTT Severe liver disease = Thrombocytopenia Rat bait toxicity = Increased APTT and PT Fibrinolysis = Increased FDP or D-dimers</p> Signup and view all the answers

    Which factor has the shortest half-life and runs out first after ingestion of rat bait?

    <p>Factor VII</p> Signup and view all the answers

    Dogs with DIC often present with spontaneous bleeding.

    <p>True</p> Signup and view all the answers

    What is the role of tissue plasminogen activator (t-PA) in fibrinolysis?

    <p>Converts plasminogen to plasmin</p> Signup and view all the answers

    The pathological activation of the coagulation system leading to generalized intravascular clotting is known as __________.

    <p>DIC</p> Signup and view all the answers

    Which of the following can impair the absorption of Vitamin K?

    <p>Liver disease</p> Signup and view all the answers

    Schistocytes can be found in a blood smear of a patient diagnosed with DIC.

    <p>True</p> Signup and view all the answers

    What is a common presentation of DIC in cats?

    <p>Clinical signs associated with the underlying disease</p> Signup and view all the answers

    The production of __________ factors is decreased in cases of cholestasis due to impaired intestinal absorption of Vitamin K.

    <p>vitamin K-dependent</p> Signup and view all the answers

    Match the following terms with their descriptions:

    <p>FDPs = Fibrin degradation products APTT = Activated Partial Thromboplastin Time PT = Prothrombin Time DIC = Disseminated Intravascular Coagulation</p> Signup and view all the answers

    What is a primary method for obtaining platelet counts?

    <p>Automated analyser count</p> Signup and view all the answers

    Splenomegaly increases the number of platelets in circulation.

    <p>False</p> Signup and view all the answers

    What are the two types of haematopoietic neoplasia?

    <p>Myeloproliferative and lymphoproliferative</p> Signup and view all the answers

    Platelet concentrations in dogs typically range from ______ to ______ x10^9/l.

    <p>200, 500</p> Signup and view all the answers

    Match the types of leukaemia with their characteristics:

    <p>Acute leukaemia = Immature blast cells; short clinical course Chronic leukaemia = More mature cells; long clinical course Leukaemic leukaemia = Many neoplastic cells in circulation Aleukaemic leukaemia = No malignant cells in circulation</p> Signup and view all the answers

    Which of the following is a method used to differentiate cell types in leukaemia?

    <p>Cytochemical staining</p> Signup and view all the answers

    Lymphoproliferative disorders always involve the bone marrow.

    <p>False</p> Signup and view all the answers

    What are the four key features that enable a diagnosis of plasma cell myeloma?

    <p>Increased plasma cell numbers, monoclonal immunoglobulin, lytic bone lesions, and renal failure.</p> Signup and view all the answers

    The term __________ refers to neoplastic disorders arising from haematogenous cells.

    <p>haematopoietic neoplasia</p> Signup and view all the answers

    Which cell type is primarily involved in myeloproliferative disorders?

    <p>Erythrocytes</p> Signup and view all the answers

    Automated analyser platelet counts can be unreliable if platelet clumping occurs.

    <p>True</p> Signup and view all the answers

    How does leukaemia typically present in terms of neoplastic cells in blood?

    <p>Increased numbers of neoplastic cells, but not always required for diagnosis.</p> Signup and view all the answers

    Myeloproliferative neoplasias originate primarily in the _______.

    <p>bone marrow</p> Signup and view all the answers

    Match the staining methods with their purposes:

    <p>Cytochemical staining = Identify cell types based on enzyme activity Immunophenotyping = Determine cell types using surface antigens Peripheral blood smear = Visualize overall blood cell population Bone marrow aspiration = Assess bone marrow architecture and cell types</p> Signup and view all the answers

    What condition is commonly responsible for severe thrombocytopenia due to increased platelet consumption?

    <p>Disseminated intravascular coagulation (DIC)</p> Signup and view all the answers

    Increased platelet destruction can result from immune-mediated thrombocytopenia (IMTP).

    <p>True</p> Signup and view all the answers

    What is the common infectious cause of thrombocytopenia in dogs?

    <p>Ehrlichiosis</p> Signup and view all the answers

    Vascular diseases resulting in bleeding disorders, such as polyarteritis nodosa, are __________ in animals.

    <p>rare</p> Signup and view all the answers

    Match the following types of thrombocytopenia with their descriptions:

    <p>Primary immune-mediated thrombocytopenia = Production of auto-antibodies against platelets Secondary immune-mediated thrombocytopenia = Induced by viruses or drugs affecting platelet surfaces Isoimmune thrombocytopenia = Sensitization of sows to foreign platelet antigens Vaccine-induced thrombocytopenia = Occurs post vaccination with modified live vaccines</p> Signup and view all the answers

    Which breed is most commonly associated with von Willebrand's disease?

    <p>Doberman</p> Signup and view all the answers

    Vitamin C deficiency can lead to weakened blood vessels due to impaired collagen synthesis.

    <p>True</p> Signup and view all the answers

    What is the primary function of Von Willebrand Factor (vWF)?

    <p>Glues platelets to exposed subendothelial collagen</p> Signup and view all the answers

    Type II BVD virus can cause platelet destruction in __________.

    <p>calves</p> Signup and view all the answers

    What is a common cause of mild thrombocytopenia after vaccination?

    <p>Vaccine-induced thrombocytopenia</p> Signup and view all the answers

    Secondary hemostasis is independent of primary hemostasis.

    <p>False</p> Signup and view all the answers

    What are megakaryocytes responsible for producing?

    <p>Platelets</p> Signup and view all the answers

    The presence of __________ can lead to prothrombotic states, increasing platelet consumption.

    <p>vasculitis</p> Signup and view all the answers

    Match the following thrombocytopenia types with their characteristics:

    <p>Immune mediated thrombocytopenia = Antibodies against platelets Vaccine-induced thrombocytopenia = After live vaccine administration Isoimmune thrombocytopenia = Colostrum sourced antibodies Ehrlichiosis = Infectious cause in dogs leading to platelet destruction</p> Signup and view all the answers

    Study Notes

    Blood Overview

    • Blood accounts for 5-10% of total body weight, varying by species (e.g., cats: 55 mL/kg; dogs: 70-100 mL/kg).
    • Blood undergoes characteristic alterations in disease states, aiding in clinical diagnosis.
    • Blood is the most frequently sampled organ in sick animals, reflecting their current health.

    Cellular Components of Blood

    • Three primary cell types in mammal blood:
      • Erythrocytes (red blood cells)
      • Leukocytes (white blood cells) including granulocytes (neutrophils, eosinophils, basophils), lymphocytes, and monocytes
      • Platelets (thrombocytes in birds)
    • Species differences exist in blood cellular components and responses to stimuli, impacting haematological data interpretation.

    Haematopoietic System

    • The haematopoietic system produces blood cells, involving organs like:
      • Bone Marrow: Main site of erythrocyte, granulocyte, monocyte, and thrombocyte production; stores iron; source of T and B-lymphocyte stem cells.
      • Liver: Major haematopoietic organ in embryonic life, stores iron, folic acid, vitamin B12; processes bilirubin; and produces erythropoietin precursor.
      • Lymph Nodes: Produce T and B-lymphocytes and plasma cells.
      • Spleen: Serves as a blood filter, stores erythrocytes and iron; involved in haematopoiesis.
      • Thymus: Differentiates stem cells into T-lymphocytes.
      • Macrophages: Phagocytize aged erythrocytes and degrade hemoglobin.
      • Gastrointestinal Tract: Absorbs dietary iron.
      • Kidneys: Produce erythropoietin in response to low oxygen levels.

    Erythropoiesis (Erythrocyte Production)

    • Erythropoiesis occurs mainly in the bone marrow, taking about 7 days from stem cell stimulation to reticulocyte release.
    • erythroid stem cells undergo several stages to mature into erythrocytes, with EPO stimulating the process.
    • Erythrocytes are stored in three pools: bone marrow (precursors), blood (mature), and spleen (mature).

    Regulation of Erythropoiesis

    • Erythropoietin (EPO) from kidneys stimulates erythrocyte formation and hemoglobin synthesis.
    • Nutritional factors like vitamin B12, B6, folic acid, and minerals (iron, copper, cobalt) are crucial for erythropoiesis.
    • Hormonal influences: Androgens promote, while estrogens inhibit erythropoiesis.

    Erythrocyte Function and Metabolism

    • Erythrocytes deliver oxygen to tissues, relying on hemoglobin for reversible oxygen binding.
    • Glucose is their primary energy source, with four metabolic pathways ensuring functionality.
      • Glycolytic pathway: Produces ATP for maintaining cell integrity; defects cause fragility.
      • Hexose monophosphate shunt: Protects hemoglobin from oxidation.
      • Methaemoglobin reductase pathway: Maintains iron in a functional state.
      • 2,3-Diphosphoglycerate pathway: Regulates oxygen affinity of hemoglobin.

    Erythrocyte Destruction

    • Erythrocytes have a limited lifespan (e.g., dog: 120 days, cat: 70 days).
    • Extravascular haemolysis removes older cells via macrophages; hemoglobin is metabolized into bilirubin.
    • Intravascular haemolysis releases hemoglobin into plasma, leading to hemoglobinaemia and potential kidney issues.

    Iron Metabolism

    • Iron is stored in erythrocytes, macrophages, and other molecules; its continual supply is critical for hemoglobin synthesis.
    • Transferrin transports iron in the bloodstream; serum transferrin decreases in iron deficiency and can increase in hemolytic anemia.
    • Total iron-binding capacity (TIBC) assesses plasma's iron-carrying capacity.

    Complete Blood Count (CBC)

    • CBC evaluates blood's cellular components and indicates animal health.
    • Assessments include:
      • Hematocrit (Hct): Volume of erythrocytes vs. total blood volume.
      • Packed Cell Volume (PCV): Percentage of blood composed of erythrocytes.
      • Red Cell Count (RBC): Number of erythrocytes per blood unit.
      • Hemoglobin Concentration (Hb): Amount of hemoglobin in blood.

    Erythrocyte Indices

    • Help classify types of anemia using parameters such as mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC).
    • MCV indicates average RBC size; deviations can indicate conditions like iron deficiency anemia.
    • MCHC measures hemoglobin concentration in packed red blood cells; abnormalities can indicate types of anemia.
    • Reticulocytes indicate bone marrow response; assessment is crucial in diagnosing anemias, with reticulocyte count considered more reliable in dogs and cats.### Leukocyte and Platelet Assessment
    • White blood cell (WBC) morphology is evaluated through blood smears.
    • Total white cell count and differential leukocyte counts are essential parameters.
    • Key platelet assessment in CBC is the platelet count, essential for evaluating haemostasis.

    Erythrocyte Morphology Learning Objectives

    • Five focus points used to assess red blood cells (RBC) in blood smears include number, size, shape, color, and additional structures.
    • Recognition of differing erythrocyte morphological features is crucial for explaining their causes in various species.
    • Hallmarks of regeneration: Anisocytosis and polychromasia are indicators of responsive bone marrow in regenerative anaemia.
    • Bone marrow aspirates may be indicated for patients with non-regenerative anaemia, leukopenia, thrombocytopenia, atypical cells, and monoclonal gammopathies.

    Blood Smear Examination

    • Abnormalities in erythrocyte morphology reveal causes of anaemia and bone marrow responsiveness.
    • Familiarity with species-specific normal erythrocyte morphology is critical.
    • Categories for assessing erythrocytes include:
      • Number (assessed via RBC indices or packed cell volume, PCV)
      • Size (anisocytosis, microcytosis, macrocytosis)
      • Shape (poikilocytosis indicates abnormal shapes)
      • Color (hypochromasia indicates lower hemoglobin content)

    Erythrocyte Characteristics

    • Size:
      • Microcytosis: small erythrocytes.
      • Macrocytosis: larger erythrocytes.
    • Color:
      • Hypochromasia presents as increased central pallor.
      • Polychromasia indicates a mix of mature cells and reticulocytes.
    • Shape:
      • Acanthocytes (spur cells) are indicative of underlying diseases like hepatic lipidosis.
      • Echinocytes (crenated cells) often result from artefacts of the smear or underlying renal issues.
      • Schistocytes arise from intravascular trauma or fragmentation.
      • Keratocytes (helmet cells) form due to oxidative or fragmentation injury.

    Erythrocyte Structures and Arrangements

    • Structures on Erythrocytes:
      • Basophilic stippling suggests lead poisoning or regenerative anaemia.
      • Heinz bodies indicate oxidative damage, commonly seen in cats.
      • Howell-Jolly bodies are remnants of nuclei, usually during regenerative responses or splenic dysfunction.
    • Arrangements:
      • Agglutination points to immune-mediated haemolytic anaemia.
      • Rouleaux formation appears as stacked erythrocytes and varies with plasma protein levels.

    Erythrocytosis

    • Defined as an increase in PCV, RBC count, or hemoglobin beyond normal levels, leading to tissue oxygenation changes.
    • Relative Erythrocytosis: Normal red cell mass with reduced plasma volume, often due to dehydration.
    • Physiologic Erythrocytosis: Temporary increase from splenic contraction during fight or flight response.
    • Absolute Erythrocytosis: True increase in red cell mass; can be primary (autonomous erythropoiesis) or secondary (response to increased erythropoietin).

    Anaemia

    • Characterized by reduced erythrocyte numbers leading to decreased oxygen delivery, indicated by clinical signs like pale mucous membranes, lethargy, and increased heart rate.
    • Classifies into:
      • Regenerative: active bone marrow response indicated by changes like reticulocytosis, anisocytosis, and polychromasia.
      • Non-regenerative: insufficient erythroid response, often requiring bone marrow evaluation for cause determination.
    • The diagnostic plan should differentiate causes based on CBC data and the nature of bone marrow response.### Non-Regenerative Anaemia
    • Non-regenerative anaemia results when the bone marrow fails to produce adequate erythrocytes to replace those lost naturally.
    • Causes may include deficiencies in erythropoietic factors, toxic bone marrow inhibition, infections, neoplasms, defective maturation of erythrocytes, or a lack of erythropoietic stem cells.
    • Repeating a CBC after 3-5 days can help differentiate non-regenerative from regenerative anaemia by observing changes in reticulocyte levels.

    Classification of Anaemias

    • Anaemias are classified based on erythrocyte size (MCV) and haemoglobin concentration (MCHC): normocytic, macrocytic, microcytic, normochromic, or hypochromic.
    • Microcytic anaemias predominantly indicate iron deficiency; they can also occur in certain breeds (e.g., Akita, Shiba) or conditions like portocaval vascular shunts.
    • Macrocytic anaemia may indicate regeneration and occurs in poodles and cats with feline leukaemia virus, as well as in horses.
    • Immune-mediated haemolytic anaemia can artifactually elevate MCV due to agglutinated red blood cells.

    Laboratory Assessment

    • Plasma protein estimation is recommended to help classify anaemia, indicating whether it is regenerative due to blood loss or haemolysis.
    • Coombs tests are useful for diagnosing immune-mediated haemolytic anaemia but are not advisable when autoagglutination is present.
    • In cases of microcytic anaemia, checking faeces for blood may identify chronic gastrointestinal blood loss, a common cause of iron deficiency.

    Regenerative Anaemias Overview

    • Regenerative anaemias arise from increased erythrocyte loss (haemorrhage) or destruction (haemolysis).

    Haemorrhagic Anaemia

    • Acute Blood Loss: Initial erythrocyte parameters (PCV, RBC, Hb, MCV, MCHC) remain normal; clinical signs evolve over hours as the blood volume is restored.
    • Causes include trauma, surgery, gastrointestinal ulcers, coagulation defects, thrombocytopenia, and bleeding tumours.
    • Chronic Blood Loss: Anaemia develops slowly; regenerative response may lessen over time due to iron depletion, causing microcytic and hypochromic characteristics.

    Haemolytic Anaemia

    • Haemolysis involves the destruction of erythrocytes; it becomes a problem when destruction outpaces production.
    • Intravascular Haemolysis: Occurs within blood vessels, causing haemoglobinaemia and haemoglobinuria, often due to mechanisms like oxidative injury or complement-mediated lysis.
    • Extravascular Haemolysis: Occurs in macrophages in the spleen, often results in splenomegaly, and usually does not present with haemoglobinaemia.

    Examples of Regenerative Anaemias

    • Immune-Mediated Haemolytic Anaemia (IMHA): Accelerated erythrocyte destruction caused by immune reactions; common in dogs, less frequent in cats and horses.

      • Characterized by severe reticulocytosis, spherocytosis, and possible autoagglutination.

    • Neonatal Isoerythrolysis: IMHA in newborns due to maternal antibodies against foetal RBC antigens; diagnosis confirmed through Coombs tests.

    Specific Types of Anemia

    • Iron Deficiency Anaemia: Commonly due to chronic blood loss or in newborns with low milk iron; leads to microcytic and hypochromic red blood cells.

    • Sporidesmin Toxicity: Causes acute haemolytic anemia in cattle, associated with impaired liver function during facial eczema season.

    • Leptospirosis: Can lead to acute haemolytic crises, particularly in young animals infected by L.pomona, causing significant RBC destruction.

    • Chronic Copper Toxicity: Causes intravascular haemolysis and is especially problematic in sheep due to their sensitivity to copper accumulation.

    Monocytes

    • Mature monocytes are larger than neutrophils with dark blue cytoplasm containing vacuoles.
    • Their nuclei vary in shape: oval, bean, horseshoe, or highly-indented.
    • Macrophages, derived from monocytes, are phagocytic and crucial for defense against facultative intracellular bacteria and fungi.
    • They remove aged cells, process antigens for lymphocyte presentation, store iron, and synthesize critical substances.
    • Close interaction between macrophages and lymphocytes is essential for antibody production and cell-mediated immunity.
    • Monocytes are produced in bone marrow and undergo a shorter maturation than neutrophils, circulating briefly in blood before becoming macrophages in tissues.
    • Macrophages can be mobile or fixed in tissues and may survive for weeks to months, multiplying and developing specific functions.
    • Different types of tissue macrophages include Kupffer cells in the liver and microglial cells in the CNS.

    Monocytosis and Monocytopenia

    • Monocytosis is an increase in blood monocyte numbers, often due to inflammation or corticosteroid response.
    • Significant inflammation, such as tissue necrosis, can lead to increased monocytes for debris clearance.
    • Corticosteroid-induced monocytosis can occur in conditions like Cushing’s disease in dogs.
    • Monocytopenia, a decrease in monocytes, is generally not clinically significant due to their low baseline levels.

    Eosinophils

    • Eosinophils have a multi-lobed nucleus with pale blue cytoplasm and prominent pink granules that vary by species.
    • Cats have rod-shaped granules, dogs have round pink granules, horses have plump spherical granules, and ruminants have numerous small, uniform round granules.
    • Functionally, eosinophils are involved in hypersensitivity, allergic reactions, and defense against parasites.
    • They are present more in tissues than in blood, with a ratio of approximately 300:1.
    • Eosinophilia is an increase in eosinophils, often linked to hypersensitivity disorders, parasitism, and other rare causes.
    • Eosinopenia, a decrease in eosinophils, may not be clinically significant and is primarily caused by corticosteroids or acute inflammatory conditions.

    Basophils

    • Basophils contain lavender to purple granules and are similar in appearance to eosinophils.
    • Their function is poorly understood, and changes in basophil numbers are rare.
    • Basophilia, an increase in basophils, is uncommon and often linked to allergies, parasites, or neoplastic diseases.
    • Routine blood counts may show no basophils, and basopenia is generally not clinically significant.

    Stress Leukogram

    • A "stress" or corticosteroid-induced leukogram occurs due to increased endogenous or exogenous glucocorticoids.
    • Common components include mature neutrophilia, lymphopenia, eosinopenia, and monocytosis (acronym: SMILED).
    • Not all components are always present; neutrophilia and lymphopenia are the most consistent findings.
    • Animals with Addison’s disease may lack a stress leukogram and can show an anti-stress leukogram.

    Disorders of Leukocytes

    • A variety of leukocyte disorders, often inherited and rare, can arise in humans and animals.
    • Bovine Leukocyte Adhesion Deficiency (BLAD) leads to recurrent infections due to neutrophil migration defects.
    • Canine Leukocyte Adhesion Deficiency (CLAD) presents similar clinical signs and leads to early mortality.
    • Pelger Huet anomaly results in hypo-segmented neutrophils while retaining normal eosinophil and basophil segmentation.
    • Canine cyclic neutropenia causes cyclic fluctuations in neutrophil numbers, leading to infections.

    Leukocyte Inclusions

    • Rarely detected in circulating neutrophils of patients with bacteremia.
    • Distemper virus infection can cause intracytoplasmic inclusions in various leukocytes.
    • Inclusions may also appear in inherited disorders such as Chediak-Higashi syndrome and hereditary anomalies of neutrophil granulation.

    Platelets

    • Platelets (thrombocytes) appear as small eosinophilic blobs in blood smears and play a vital role in hemostasis.
    • Produced from megakaryocytes in the bone marrow, which have a high number of nuclei and abundant granular cytoplasm.
    • Platelet lifespan in circulation is about 8-12 days; they are mostly destroyed while maintaining vascular integrity.
    • Normal platelet counts in dogs range from 200-500 x10^9/L, with automated counts being more accurate than manual counts.

    Haematopoietic Neoplasia

    • Neoplasia of hematogenous cells is classified into myeloproliferative and lymphoproliferative disorders.
    • Myeloproliferative disorders involve neoplasms of non-lymphoid blood cells, while lymphoproliferative disorders come from lymphoid cells.
    • Leukaemia is characterized by neoplastic proliferation in the bone marrow, confirmed by the presence of neoplastic cells.
    • Diagnosis involves cytochemical staining and immunophenotyping to differentiate cell types and assess prognosis.

    Classification and Diagnosis of Leukaemias

    • Leukaemia can be classified by maturity (acute with blast cells vs. chronic with mature cells) and the number of cells in circulation.
    • Accurate classification aids in treatment decisions and prognosis; distinguishing acute and chronic leukaemias is critical for treatment approaches.### Leukaemia Types
    • Leukaemic leukaemia: Characterized by numerous neoplastic cells in circulation, resulting in a significantly increased nucleated cell count.
    • Subleukaemic leukaemia: Displays a small number of malignant cells in the bloodstream, with normal or slightly elevated nucleated cell counts.
    • Aleukaemic leukaemia: None of the malignant cells are found in circulation.

    Changes in Complete Blood Count (CBC)

    • Hematological abnormalities can arise with haematopoietic neoplasia, dependent on disease stage and bone marrow involvement.
    • Advanced disease may show an increased number of large blast forms transferred into circulation.
    • Myelopthisis occurs when the bone marrow is primarily replaced by malignant blast cells, leading to non-regenerative anaemia and thrombocytopenia.

    Secondary Tumours

    • Lymph nodes are frequent sites for metastasis, notably from carcinomas, which can completely replace the nodes.
    • Epithelial cells in lymph node aspirates indicate malignancy; however, care is needed to avoid contamination from nearby tissues.
    • The spleen is less common for carcinoma metastasis but is often involved in lymphoid, histiocytic, or myeloid tumours.

    Lymphoproliferative Disorders

    • Neoplasms from lymphocytes or plasma cells are termed lymphoproliferative neoplasms and are more prevalent than myeloproliferative neoplasms.
    • Lymphoma refers to neoplastic masses, while "lymphoid leukaemia" indicates lymphoid malignancies in bone marrow and blood.

    Lymphoid Leukaemia

    • Primary Lymphoid Leukaemia: Arises in bone marrow, commonly classified as acute lymphoblastic leukaemia (ALL) or chronic lymphocytic leukaemia (CLL).
    • ALL: Contains large, immature lymphoblasts, leading to lymphocytosis, anaemia, and thrombocytopenia. Prognosis is poor with usual short survival; temporary remission possible with chemotherapy.
    • CLL: Features small, well-differentiated lymphocytes, indicating a substantial lymphocytosis in CBC. Diagnosis is aided by recognizing the greater magnitude of lymphocytosis and the increased lymphocyte proportion in the bone marrow. Prognosis for treated cases averages around 450 days, offering a better outlook than ALL.

    Lymphoma Overview

    • Lymphoma is highly significant in domestic animals, always malignant despite the "-oma" suffix.
    • Lymphoid neoplasia can evolve into leukaemia but usually occurs independently.
    • Classification includes sporadic vs. viral-associated forms and distinction based on lesion distribution and tissue architecture.
    • Immunophenotyping helps identify specific T- or B-cells, influencing chemotherapy response rates, with B-cell lymphomas typically showing better responses.

    Feline Lymphoma

    • The most common neoplasm in cats, with forms including multicentric, alimentary, thymic, and leukaemic involvement.
    • Anorexia, weight loss, and gastrointestinal signs are typical.
    • Retrovirus-associated lymphoma, often linked to feline leukaemia virus (FeLV), tends to affect younger cats.

    Thrombocytes and Disorders

    • Thrombocytosis: Increased platelet numbers are usually reactive and associated with other conditions like inflammation or neoplasia.
    • Thrombocytopenia: A common finding, spontaneous bleeding can occur with counts below 25 x 10^9/L, though it may happen at higher levels due to acute demand.
    • Artefactual thrombocytopenia: Can arise from sample processing errors.
    • True thrombocytopenia causes: Include decreased production, increased consumption, increased destruction, or sequestration.

    Platelet Disorders

    • Increased Production Issues: May stem from bone marrow diseases, infectious agents, or exposure to certain drugs or toxins.
    • Consumption: Notable in trauma, surgery, or disseminated intravascular coagulation (DIC).
    • Sequestration: Occurs in conditions like splenomegaly leading to mild thrombocytopenia.
    • Destruction: Immune-mediated thrombocytopenia (IMTP) is a significant cause, with antibodies targeting platelets leading to their phagocytosis.

    Von Willebrand's Disease (vWD)

    • Occurs due to a deficiency or functional defect in von Willebrand factor, essential for platelet adhesion.
    • Common in breeds like Dobermans, Welsh Corgis, and others, it can manifest with diverse bleeding severity.

    Secondary Haemostasis

    • Involves the formation of fibrin to stabilize the platelet plug through a cascade of enzymatic reactions.
    • Coagulation factors are primarily synthesised by the liver, necessitating normal liver function for effective haemostasis.
    • Intrinsic and extrinsic pathways converge at the activation of Factor X, leading to thrombin formation, which further promotes the coagulation cascade.### Coagulation and Clotting Mechanisms
    • All components must be functional for effective clotting; it is a self-perpetuating process with interconnections between various pathways.
    • Calcium is essential for clotting and links different coagulation factors; tubes with calcium chelators (EDTA, citrate, oxalate) prevent clotting in blood samples.
    • Vitamin K is required as a cofactor for binding coagulation factors II, VII, IX, and X, which are necessary for clotting.
    • Factors VII and IX are located on the X chromosome, making them sex-linked.
    • Fibrin clot formation is confined to platelet surfaces, as certain coagulation reactions occur on phospholipid layers of platelets.

    Testing Secondary Haemostasis

    • Prothrombin Time (PT) measures the time for fibrin clot formation in citrated plasma after adding factor VII activator; prolonged PT indicates defects in the extrinsic or common pathways.
    • Activated Partial Thromboplastin Time (APTT) assesses clotting time in citrated plasma with a factor XII activator; a prolonged APTT indicates intrinsic or common pathway issues.
    • Thrombin Time (TT) evaluates fibrin formation in plasma after adding thrombin; it reflects fibrinogen levels, not the common pathway.
    • A coagulation profile includes PT, APTT, TT, platelet count, and fibrinogen concentration.

    Sample Handling for Accurate Results

    • Blood must be collected in a light blue vacutainer with sodium citrate to ensure appropriate anticoagulation.
    • Accurate blood-to-anticoagulant ratio and gentle mixing are crucial to prevent hemolysis.
    • Samples must be discarded if clotted or hemolyzed; proper venipuncture is essential to avoid platelet clumping.
    • Plasma should be separated within 30 minutes of collection to reduce clotting factor loss.

    Activated Coagulation Time (ACT)

    • ACT is an in-clinic test assessing clotting time in fresh whole blood, with normal values being 60-95 seconds for dogs and 50-75 seconds for cats.
    • Prolonged ACT indicates defects in the intrinsic or common pathways, similar to APTT.
    • The test must be conducted at 37°C for valid results.

    Disorders of Secondary Haemostasis

    • Bleeding disorders can arise from deficiencies in intrinsic, extrinsic, or common pathways; they often manifest as significant hemorrhages in organs or body cavities.
    • Inherited deficiencies, while rare, can include Hemophilia A (factor VIII deficiency) and Hemophilia B (factor IX deficiency).

    Vitamin K Deficiency and Coumarin Toxicity

    • Vitamin K is crucial for activating coagulation factors II, VII, IX, and X; its inactivation leads to impaired coagulation.
    • Coumarin ingestion can prevent vitamin K reactivation, resulting in bleeding 3-7 days post-exposure.
    • Increased PT indicates toxicity, especially following ingestion of rat bait; factors such as diet and drug interactions can exacerbate toxicity.

    Impact of Severe Liver Disease on Coagulation

    • The liver synthesizes most clotting factors, and liver dysfunction may impede coagulation.
    • Cholestasis can decrease vitamin K absorption, affecting levels of vitamin K-dependent factors; increased APTT and PT may occur.
    • Balance of clotting factors and inhibitors determines bleeding tendency in affected animals.

    Disseminated Intravascular Coagulation (DIC)

    • DIC involves pathological activation of coagulation that leads to extensive clotting within blood vessels, often triggered by various disorders.
    • Symptoms of DIC may include spontaneous bleeding, organ dysfunction, and signs of anemia, especially in dogs.
    • Laboratory findings can reveal thrombocytopenia, increased PT and APTT, decreased fibrinogen, and increased fibrin degradation products.

    Fibrinolysis and Coagulation Regulation

    • Fibrinolysis counteracts coagulation, breaking down fibrin clots via the activation of plasmin from plasminogen.
    • Endothelial cells help regulate coagulation by maintaining physical separation of platelets and collagen, producing anticoagulants like thrombomodulin, and activating fibrinolysis via tissue plasminogen activator.
    • Injury to the endothelium removes these regulatory functions, promoting clot formation.

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    Test your knowledge on animal physiology and blood composition with this quiz. Explore concepts like the percentage of body weight that blood makes up, types of blood cells, and the origins of erythrocytes. Perfect for students studying veterinary medicine or biology.

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