Hemostatic and RBC Disease (STOLEN)

Blood components

Plasma, cellular components, and platelets

Blood function

Transport, regulate, defend

Hematopoiesis

Continuous production of all blood cells throughout life

Fetus hematopoiesis

Blood cell production in the liver and spleen

Newborn hematopoiesis

Blood cell production in the red bone marrow

Red bone marrow

Contains stem cells that produce red and white blood cells and platelets

Adult animal hematopoiesis

Red bone marrow sites vary by species

Hematopoietic stem cell

Primitive stem cell type from which all blood cells derive

Hematopoiesis types

Erythropoiesis, luekopoiesis, thrombopoiesis

Erythropoiesis

Process of creating red blood cells

Erythropoiesis process

Stem cells divide, lose nuclei, produce hemoglobin, and mature

Erythropoiesis timelines

1 week in dog, 4-5 days in cow, 36 hours in bird

Erythropoietin (EPO)

Hormone that controls erythropoiesis process

Hypoxia stimulates ______

Production of EPO

Lifespan of RBCs

Cats: 68 days, Dogs: 120 days, Cows: 160 days

Nucleated RBCs (nRBCs)

Immature RBCs produced in response to loss or destruction of RBCs

RBC structure

No nucleus, mitochondrion, or ribosomes; contains water, hemoglobin, and structural elements

Mature RBCs

Biconcave discs with thinner central zone

Thrombopoiesis

Differentiation of stem cells into megakaryocytes, releasing platelets

Thrombopoiesis timeline

Up to 7 days

Thrombopoietin

Hormone produced by the liver to stimulate platelet production

CBC tells us

a test that would evaluate primary hemostasis

coagulation panel tells us

a panel that tells us about PT and aPTT; evaluate secondary hemostasis by evaluating extrinsic, intrinsic, and common pathways of coagulation cascase

Clotting disorders (bleeding disorders)

Disorders that interfere with normal hemostatic process

Clotting disorder origins

Primary hemostasis (platelets), secondary hemostasis (coagulation cascade), blood vessel

Clinical signs of clotting disorders

Hemorrhage, hematomas, epistaxis, ecchymosis, hematuria, melena

Hematomas

Localized swelling filled with blood caused by a break in a blood vessel wall

Epistaxis

Nosebleed

Ecchymosis

Large bruised areas

Petechiae

Tiny red/purple spots of blood in skin or mucous membrane

Hematuria

Blood in urine

Melena

Dark blood in feces

Hyphema

Blood accumulation in the anterior portion of the eye

Thrombocytopenia

Deficiency in platelets in the blood

Thrombocytopenia causes

Decreased production, increased destruction, increased consumption, impaired function

Decreased platelet production

Thrombocytopenia due to damaged or suppressed bone marrow

Increased platelet destruction

Thrombocytopenia due to the body's destruction of its own platelets

Immune-mediated thrombocytopenia (ITP)

Type 2 hypersensitivity where antibodies are produced against platelets

Tick-borne ITPs

Ehrlichiosis, Anaplasma platys, A. phagocytophilum, Rocky Mountain spotted fever

Ehrlichiosis

Tick-borne bacterial infection causing fever, lymphadenopathy, and swelling

Anaplasma platys

Tick-borne bacteria causing mild to moderate thrombocytopenia

A. phagocytophilum

Tick-borne bacteria causing lameness, bleeding, and fever

Rocky Mountain Spotted Fever

Caused by Rickettsia rickettsia; fever, lethargy, epistaxis, hemorrhage, lameness, CNS signs, death

Drug-formed ITPs

Unexplained thrombocytopenia from certain medications

Increased platelet consumption

Thrombocytopenia due to deregulation of normal blood clotting/dissolving

Disseminated intravascular coagulation (DIC)

Extreme complications of life-threatening conditions leading to deregulation of blood clotting

DIC triggers

Heat stroke, shock, severe trauma, infection, cancer

DIC pathogenesis

Produces diffuse endothelial damage, platelet adhesion/activation, thrombus formation, and fatal bleeding

Impaired platelet function

Thrombocytopenia due to diseases and drugs affecting platelet adhesion and aggregation

NSAID effect on platelets

Aspirin inhibits cyclooxygenases, decreasing thromboxane, which supports platelet aggregation

Von Willebrand disease

Blood clotting disorder from deficiency or deficient quality of von Willebrand factor

Von Willebrand's factor

Protein complex that holds platelets together and onto the surface of a torn blood vessel

Von Willebrand disease breeds

Doberman pinschers, golden retrievers, shetland sheepdogs, rottweilers, mini schnauzers, german shepherds, german short-haired pointers, poodles, scottish terriers

Von Willebrand disease signs

Bleeding with minor injury or surgery, spontaneous bleeding, recurring epistaxis, hematuria, melena

Coagulation factor disorders

Disorders that interfere with the coagulation cascade and affect clotting

Coagulation factor disorder causes

Clotting factor deficiency, decreased production, increased consumption

Clotting factor deficiency example

Hemophilia A (factor VIII deficiency)

Hemophilia A clinical signs

Prolonged bleeding, hemorrhage, spontaneous bleeding resulting in lameness, death

Decreased clotting factor production examples

Liver disease, toxins

Liver disease

Disease that affects the liver, decreasing production of clotting proteins

Infectious canine hepatitis (canine adenovirus 1)

Viral liver infection that affects young dogs

Canine adenovirus 1 clinical signs

Fever, vomiting, anorexia, CNS signs; sometimes hemostatic abnormalities or liver cirrhosis, vasculitis, icterus, corneal cloudiness

Leptospirosis

Zoonotic bacterial liver infection that leads to kidney failure with liver failure

Leptospirosis clinical signs

Lethargy, polyuria, polydipsia, oliguria, anuria, anorexia, vomiting; sometimes hemostatic abnormalities or thrombocytopenia

Coccidioidomycosis (valley fever)

Fungal liver infection spread through inhaled dust

Coccidioidomycosis clinical signs

Abscesses in lungs and joints in dogs, skin lesions in cats; rarely ascites, icterus, hepatomegaly

Histoplasmosis

Fungal liver infection spread through inhaled spores

Histoplasmosis clinical signs

Respiratory or disseminated infection, cough, lethargy, anorexia

Canine chronic hepatitis

Acute hepatitis turned chronic

Canine chronic hepatitis etiologies

Adenovirus 1, lepto, drug-associated, copper storage hepatopathy, immune-mediated, idiopathic

Cholangiohepatitis

Inflammation in the liver/biliary tract preventing bile from passing

Cholangiohepatitis etiologies

Immune-mediated, bacterial

Hepatic lipidosis in cats

Triglycerides accumulate within liver cells and affect function

Anticoagulant rodenticides

Poisons used to kill rodents

Rodenticide toxin behavior

Interferes with the ability of the liver to recycle vitamin K1

Rodenticide toxin clinical signs

Spontaneous bleeding, lethargy

Rodenticide treatment

Induce emesis, give activated charcoal, administer vitamin K1, monitor PT or PIVKA, FFP or whole blood if actively bleeding

Increased clotting factor consumption example

DIC, snake bites, spider bites

Snake bite clinical signs

Tissue discoloration, dark fluid oozing, neuro signs, tachypnea, dyspnea, renal failure

Brown recluse spider bite signs

Blister followed by necrotic skin, vomiting, fever, lethargy, bleeding disorders, organ damage

Endothelial bleeding issues

Bleeding secondary to endothelial injury; congenital vascular defect, trauma, tumors, vasculitis

Congenital vascular defect

Collagen defect leading to weak structural support of blood vessels

Tumor-induced bleeding

Tumors growing into neighboring blood vessels and causing bleeding

Vasculitis

Inflammation of blood vessels causing thickening, scarring, weakening

Thrombus

Abnormal aggregation of platelets and fibrin under abnormal conditions

Thromboembolism

Thrombus traveling in the bloodstream and getting stuck in a small vessel

Ischemia

Inadequate blood supply causing shortage of O2 and glucose for cellular metabolism

Infarction

Irreversible tissue death due to inadequate blood supply

Hypertrophic cardiomyopathy (HCM)

Most common form of feline heart disease

Feline aortic thromboembolism

Thrombus formation in the left atrium, traveling to the aorta and lodging at the aortic bifurcation

Anemia

Decreased hematocrit and total red cell count

Regenerative anemia

Bone marrow responds appropriately to decreased RBCs by increasing production

Non-regenerative anemia

Bone marrow responds inadequately to increased need

Anemia clinical signs

Pale mm, depression, weakness, dyspnea, exercise intolerance, heart murmurs, icterus

Icterus

Yellow pigment of skin, tissues, fluids caused by deposition of bile pigments

Anemia causes

RBC loss, destruction, or decreased production in bone marrow

Anemia via blood loss

Hemorrhage

Anemia via RBC destruction

Hemolysis, immune-mediated hemolytic anemia (IMHA)

Hemolysis

Destruction of RBCs within the body

IMHA

Type 2 hypersensitivity where antibodies are produced against RBCs