Haematological & Cardiac Diseases Flashcards
Haemolytic Anaemia Aetiology?
-immune mediated
-some drugs, toxaemia, incompatible blood transfusion
Haemolytic Anaemia Pathophysiology?
-destruction of red blood cells by the animals immune system or due to parasites or toxin eventually leading to reduced circulating red cell volume
What does the bone marrow attempt to do in response to the destruction of RBC’s?
-bone marrow attempts to respond by producing a regenerative anaemia releasing immature cells from bone marrow
What does haemolysis lead to in some cases?
-increased bilirubin in the animals blood
What are the clinical signs of anaemia?
-pale mucous membranes
(due to lack of RBC/oxygen)
-weakness
(lack of oxygen going to body tissues)
-murmur
(due to changes in the blood flow)
-tachycardia
(due to heart working harder)
-dyspnoea
-inappetent
-petechiation (small red bruises)
How can anaemia be diagnosed?
-history and clinical signs
-packed cell volume test
-blood smears
-mean cell volume
-Coombs test
What does the Coombs test do?
-detects the presence of antibodies against circulating red blood cells in the body, which induce haemolysis
What is the difference between direct and indirect Coombs test?
Direct looks for antibodies that are stuck to red blood cells
Indirect looks for antibodies floating in the liquid part of the blood, called serum
Dilated cardiomyopathy aetiology?
-idiopathic
-may be related to genetic biochemical defects
-some cats affected is idiopathic
Dilated cardiomyopathy pathophysiology?
-progressive thinning of the myocardium which impairs the efficiency of the heart contraction
-eventually AV valve stretch leading to regurgitation of blood and atrial enlargement
What happens to the atria and the heart wall?
Atria becomes enlarged
Heart wall stretches becoming ballooned
What does this lead to?
-may lead to abnormalities in the heart rate and rhythm
-eventually falling CO leads to signs of congestive heart failure
Dilated cardiomyopathy clinical signs?
-lethargy
-depression
-anorexia
-exercise intolerance
-cough
-murmur
-sudden death
Dilated cardiomyopathy diagnosis?
-history and clinical signs
-chest radiographs (see size of heart)
-ECG (listen to heart rhythm)
-blood pressure measurements
-ECHO cardiography
-thoracic auscultation (to grade murmurs)
Hypertrophic cardiomyopathy aetiology?
-idiopathic
-can be genetic
-often secondary to hyperthyroidism
Hypertrophic cardiomyopathy pathophysiology?
-progressive thickening of the ventricular muscle
-enlarged heart and thickened walls
-reduced cardiac output, back pressure and atrial enlargement
What happens to the chambers in this condition?
-chambers become narrowed reducing chamber volume
Are signs of heart failure commonly seen?
-May only be seen in advanced stages of the disease
Hypertrophic cardiomyopathy clinical signs?
-murmur
-lethargy
-depression
-anorexia
Leads to heart failure, dyspnoea and tachypnoea
Is hypertrophic cardiomyopathy commonly diagnosed?
Has a long silent phase
-cardiac ultrasound van be used to visualise the heart
What is aortic thrombo-embolism?
Common complication of hypertrophic cardiomyopathy
Aortic thrombo-embolism pathophysiology?
-thrombus leaves the heart and lodges in the caudal aorta obstructing blood flow
-thrombi develop due to poor blood flow through the heart leading to stagnation of blood causing blood clots
Aortic thrombo-embolism clinical signs?
-acute paralysis of the hindlimbs
-no arterial pulse in the affected limbs
-limbs cold to touch
-pain
Mitral valve disease aetiology?
-malformation of the mitral or tricuspid valve
Mitral valve disease pathophysiology?
-blood regurgitates into the atria
-increased workload leading to enlargement
-congestion
-right sided tricuspid heart failure
-left sided mitral heart failure
Mitral valve disease clinical signs?
-May or may not show signs
-heart murmur
-present with heart failure
Why are pale mucous membranes seen (anaemia)?
-reduction in RBC flowing to the gums
-decreased erythrocytes
Why is an exercise intolerance seen (anaemia)?
-reduced oxygen flow to the tissues in the body
-causes stress to the systems
Why is the patient tachycardic (anaemia)?
-heart is overworking to increase the oxygen flow in the blood
Why might a patient be jaundiced (anaemia)?
-due to haemolytic anaemia which causes the breakdown of RBC’s
-bilirubin breaking down the RBC generating a yellow pigment
What is a PCV test, why is it chosen (anaemia)?
-measures the total number of erythrocytes as a percentage of total blood volume
-by centrifuge
-can be done in house, cheap, quick, easy
What is a blood smear, why is it used (anaemia)?
-whole blood sample evaluated under a microscope
-allows evaluation of morphology of blood cells as well as cell counts
-quick, simple, can be done in house
What is a combs test, why is it used (anaemia)?
-lab test that detects the presence of anti-erythrocyte antibodies in plasma
-definitive test for autoimmune haemolytic anaemia
What is snap tests, why is it used (anaemia)?
-elisa tests blood for antigen or antibodies to viruses as some can cause anaemia
-simple and rapid results
Why does hypertrophic cardiomyopathy cause the following signs; murmurs, tachycardia, dyspnoea?
-due to the blood flow being disrupted
-heart overworking due to trying to get as much blood out due to reduced C02 levels
-due to organs not working properly
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Why does dilated cardiomyopathy cause the following signs; murmur, dyspnoea, syncope?
-due to regurgitation of blood
-due to enlargement of heart which causes pressure in the thorax
-due to irregular heart rate, might not get enough blood to the brain causing fainting
How is mitral valve disease diagnosed?
-radiographs to look at heart
-ultrasound to show function of heart and visualise valves
