PATHOLOGY - Cardiac Pathology Flashcards
What is heart failure?
Heart failure is when the heart is unable to pump enough blood around the body to meet the body’s demand
What are the six underlying mechanisms of heart failure?
Pump failure
Obstruction
Regurgitated blood flow
Shunted blood flow due to congenital disease
Heart/major blood vessel rupture
Cardiac conduction disorders (arrhythmias)
What are the three clinical signs of acute heart failure?
Intermittent weakness
Syncope
Sudden death
What is syncope?
Syncope is the loss of consciousness for short periods of time caused by cerebral hypoperfusion
What causes sudden death in acute heart failure?
Cardiogenic shock (cells don’t receive enough oxygenated blood leading to cell death) and acute pulmonary oedema
What is congestive heart failure?
Congestive heart failure is chronic heart failure which leads to congestion and consequential oedema around the body
What are the two classifications of heart failure based on pumping ability?
Systolic heart failure
Diastolic heart failure
What is systolic heart failure?
Systolic heart failure is a failure in ventricular contraction during systole
What is diastolic heart failure?
Diastolic heart failure is a failure in ventricular relaxation/ventricular filling during diastole
What are the three anatomical classifications of heart failure?
Left-sided heart failure
Right-sided heart failure
Biventricular heart failure
What are the consequences of left sided heart failure?
Left sided heart failure is when the left ventricle is unable to pump enough blood into the aorta, causing tissue hypoperfusion. In addition, left-sided heart failure can cause a backup of blood into the pulmonary veins and pulmonary circulation, causing pulmonary congestion, increasing hydorstatsic pressure, resulting in pulmonary oedema
What are the four main clinical signs of left-sided heart failure?
Tissue hypoperfusion
Pulmonary congestion/oedema
Dyspnoea
Coughing
What is a key histological sign of chronic left-sided heart failure?
Haemosiderin-laden macrophages (heart failure cells)
What are Haemosiderin-laden macrophages (heart failure cells)?
The pulmonary congestion caused by left-sided heart failure can cause erythrocytes and proteins to leave the blood vessels into the alveoli where they will be engulfed by alveolar macrophages, leading to the formation of haemosiderin-laden macrophages (heart failure cells)
How does left-sided heart failure initially cause left ventricular hypertrophy?
When there is decreased cardiac output, this triggers vasoconstriction and hypertension to maintain core tissue perfusion (heart and brain). However, this hypertension causes increased arterial pressure and thus increased afterload and increased cardiac workload, which can lead to hypertrophy of the left ventricle. Initially, this hypertrophy serves as a compensatory mechanism to maintain cardiac output
What are the long-term effects of left ventricular hypertrophy?
Over time, left ventricular hypertrophy will reduce the ability of the ventricle to relax leading to impaired ventricular filling and thus a decrease in stroke volume and cardiac output
How does the renin-angiotensin aldosterone system respond in response to left-sided heart failure?
When there is decreased perfusion of this kidneys, this will activates the renin-angiotensin aldosterone system. This will lead to sodium and water reabsorption and increased fluid retention, thus increasing the blood volume that is entering the left ventricle, increasing contractility, stroke volume and cardiac output
What is the harmful effect of renin-angiotensin aldosterone system activation in response to left-sided heart failure?
The renin-angiotensin aldosterone system increases blood volume which will increase the back up of blood into the pulmonary veins and pulmonary circulation, worsening the pulmonary congestion and oedema. Increasing the blood volume will also increase the central venous pressure and the preload
How does the sympathetic nervous system respond to left-sided heart failure?
The sympathetic nervous system causes an increase in the heart rate to increase cardiac output, causes vasoconstriction to redirect blood to core tissues (heart and brain) and activates the renin-angiotensin aldosterone system
What are the consequences of right sided heart failure?
Right sided heart failure is when the right ventricle is unable to pump enough blood into the pulmonary trunk, causing pulmonary hypoperfusion. In addition, right-sided heart failure can cause a backup of blood into the cranial and caudal vena cavae and systemic circulation, causing systemic congestion resulting in systemic oedema
What are the five main clinical signs of right-sided heart failure?
Pulmonary hypoperfusion
Jugular venous distension
Ascites
Hepatomegaly
Splenomegaly
What is ‘nutmeg’ liver?
‘Nutmeg’ liver is the mottled appearance of the liver as a result of chronic hepatic venous congestion
What is the term used to describe right-sided heart failure caused by respiratory disease or dysfunction?
Cor pulmonale
How can high altitude disease (brisket disease) cause cor pulmonale?
Increased altitude causes hypoxaemia leading to pulmonary vasoconstriction and pulmonary hypertension, increasing the arterial pressure and afterload, so the right side of the the heart has to contract more to overcome this resistance to eject blood into the pulmonary trunk and into the lungs
What is cardiac tamponade?
Cardiac tamponade is compression of the heart due to pericardial effusion
What is haemopericardium?
Haemopericardium is the accumulation of blood in the pericardium
List three possible causes of haemopericardium
Atrial rupture
Aortic rupture
Neoplasia (haemangiosarcoma)
What is hydropericardium?
Hydropericardium is transudate oedema in the pericardium
List five possible causes of hydropericardium
Congestive heart failure
Pulmonary hypertension
Renal failure
Hypoproteinaemia
Systemic diseases
What is pericarditis?
Inflammation of the pericardium
What is Traumatic reticulopericarditis (hardware disease)?
Traumatic reticulopericarditis (hardware disease) is damage to the reticular wall caused by the ingestion of wire, nails etc, allowing bacteria to enter the peritoneum and cause peritonitis which can progress to pericarditis
How can pericarditis be diagnosed?
Sample pericardial fluid for bacterial culture and viral PCR
What is a pericardial hernia?
A pericardial hernia is protrusion of the abdominal viscera through the diaphragm into the pericardium
What are the two main physiological changes seen in the myocardium?
Hypertrophy
Atrophy
What is a common physiological cause of myocardial hypertrophy?
Increased workload
What is a common physiological cause of myocardial atrophy?
Decreased workload
What is concentric myocardial hypertrophy?
Concentric myocardial hypertrophy is an increase in the cardiomyocyte width
What causes concentric myocardial hypertrophy?
Pressure overload of the myocardium
What is eccentric myocardial hypertrophy?
Eccentric myocardial hypertrophy is an increase in the cardiomyocyte length
What causes eccentric myocardial hypertrophy?
Volume overload of the myocardium
What is the key feature that is only seen in pathological myocardial hypertrophy?
Fibrosis
List four examples of myocardial disease
Myocardial degeneration
Myocardial necrosis
Myocarditis
Cardiomyopathy
What are the four possible causes of myocardial degeneration?
Myocardial lipofuscinosis
Fatty degeneration
Vacuolar degeneration
Myocytolysis
What is myocardial lipofuscinosis?
Myocardial lipofuscinosis is the accumulation of lipofuscin in the cardiomyocyte cytoplasm
What is fatty degeneration of the myocardium?
Fatty degeneration of the myocardium is lipid accumulation in the cardiomyocyte cytoplasm
What is vacuolar degeneration of the myocardium?
Vacuolar degeneration of the myocardium is water accumulation in the cardiomyocyte cytoplasm
What is myocytolysis?
Myocytolysis is lysis of the cardiomyocytes
What is the histological appearance of myocardial necrosis?
Hypereosinophilic muscle fibres
Pyknotic nuclei
How does myocardial necrosis decrease the contractility of the myocardium?
Necrosis causes inflammation and fibrosis which is non-functional and thus decreases contractility
List three biomarkers which can be used to identify myocardial necrosis
Creatine kinase
Cardiac troponin 1
Natriuretic enzymes
Why is creatine kinase an unreliable biomarker for myocardial necrosis?
Creatine kinase can also be elevated due to skeletal muscle injury and is thus not specific to the heart
What is myocarditis?
Myocarditis is inflammation of the myocardium
Give two examples of viruses which can cause myocarditis in dogs
Canine parvovirus 2
Canine distemper virus
Which key histological feature is indicative of viral myocarditis?
Intranuclear inclusion bodies
What is the most common cause of bacterial myocarditis in cats and dogs?
Bartonella bacterial infection
Which disease can progress to myocarditis?
Traumatic reticulopericarditis
What is cardiomyopathy?
Cardiomyopathy is a general term used to describe diseased or dysfunction of the myocardium
What is primary cardiomyopathy?
Primary cardiomyopathy is cardiomyopathy without an underlying pathological cause
What are the three classifications of primary cardiomyopathy?
Hypertrophic primary cardiomyopathy
Dilated primary cardiomyopathy
Restrictive primary cardiomyopathy
What is the key characteristic of hypertrophic primary cardiomyopathy?
The presence of myocardial hypertrophy
What is the key characteristic of dilated primary cardiomyopathy?
The presence of ventricular dilation
What is the key characteristic of restrictive primary cardiomyopathy?
Stiffness of the ventricles
Which two breeds of cat are predisposed to feline hypertrophic primary cardiomyopathy?
Maine Coon
Rag Doll
Why are Maine Coon and Rag Doll cats predisposed to Feline hypertrophic primary cardiomyopathy?
Maine Coon and Rag Doll cats have a mutation in the gene encoding for the cardiac myosin-binding protein C (MYBPC)
Which species is most likely to suffer from dilated primary cardiomyopathy?
Dogs
What are the two forms of canine dilated primary cardiomyopathy?
Fatty infiltrative degenerative dilated cardiomyopathy
Attenuated wavy fibre dilated cardiomyopathy
Which two breeds of dog commonly suffer from fatty infiltrative degenerative dilated cardiomyopathy?
Boxers
Dobermans
What is secondary cardiomyopathy?
Secondary cardiomyopathy is cardiomyopathy with an underlying pathological cause
What are the two most common underlying causes of secondary cardiomyopathy in cats?
Hyperthyroidism
Taurine deficiency
What are the seven forms of heart valve disease?
Valve haemocysts
Valve lymphocysts
Valve calcification
Valve mineralisation
Endocardiosis (Myxomatous valvular degeneration)
Endocarditis
Chordae tendinae rupture
What are heart valve haemocysts?
Heart valve haemocysts are blood filled cysts on the valve cusps
What are heart valve lymphocysts?
Heart valve lymphocysts are lymph filled cysts on the valve cusps
What is endocardiosis (myxomatous valvular degeneration)?
Degenerative valve disease characterised by myxomatous degeneration where elastin and collagen are disrupted leading to proteoglycan deposition resulting in valve cusp and chordae tendinae thickening
Which valve is most likely to have endocardiosis?
Mitral valve
Which breed of dog is predisposed to mitral myxomatous valvular degeneration (endocardiosis)?
Cavalier King Charles Spaniels
What is endocarditis?
Inflammation of the endocardium and the heart valves
Which valve is most likely to have endocarditis?
Tricuspid valve
Describe the pathogenesis of infective endocarditis
Trauma to the endocardium and/or heart valves causes fibrin and platelet deposition and aggregation known as non-bacterial thrombotic vegetation (NBTV). Damage to bacterial colonised tissues in the body can cause transient bacteraemia and circulating bacteria can aggregate and colonise non-bacterial thrombotic vegetation, stimulating the inflammatory response leading to more platelet aggregation and fibrin deposition, causing propagation of the vegetation resulting in infectious endocarditis
How does the host immune system usually defend against infective bacteraemia if there is no prior trauma to the endothelium/heart valves?
Normally the endothelium and heart valves would be resistant to bacteraemia due to the bacteriacidal proteins produced by platelets knows as thrombocidins
What allows circulating bacteria to adhere to non-bacterial thrombotic vegetation (NBTV)?
Circulating bacteria with microbial surface components that recognise adhesive matrix molecules (MSCRAMM) can adhere to non-bacterial thrombotic vegetation (NBTV)
What are the four main consequences of infective endocarditis?
Persistent bacteraemia
Heart valve damage
Septic emboli
Antigen-antibody complex deposition
(T/F) Endocarditis is mostly caused by Gram+ (G+) bacteria
TRUE.
List five examples of Gram+ (G+) bacteria which can cause endocarditis in dogs
Streptococcus
Staphylococcus
Enterococcus
Corynebacterium
Bartonella
Which bacteria most commonly causes endocarditis in cattle?
Arcanobacterium pyogenes
Which bacteria most commonly causes endocarditis in pigs?
Erysipelothrix rhusiopathiae
Which G- bacteria is most likely to cause endocarditis?
E. coli
What are the eight clinical signs of infective endocarditis?
New heart murmur
Congestive heart failure
Bacteraemia
Septic embolisation
Organ infarction
Glomerulonephritis
Uveitis
Polyarthritis
How does infective endocarditis cause a heart murmur?
Bacteria causing infective endocarditis produce proteinase enzymes which can cause structural damage to the heart valves, resulting in the inability of the valves to close properly resulting in the backflow, regurgitation and turbulence of blood, causing a heart murmur
How does infective endocarditis cause organ infarction?
Fragments of the infected vegetation can enter the bloodstream resulting in septic embolisation which can cause blockage of blood vessels causing infarction of the organs which are supplied by those blood vessels
How does infective endocarditis cause glomerulonephritis, uveitis and/or polyarthritis?
The bacteraemia caused by infective endocarditis stimulates the host immune system to form antigen-antibody complexes which can be deposited into the glomerulus (glomerulonephritis), eyes (uveitis) and/or joints (polyarthritis)
Why is hypoproteinaemia and hyperproteinuria often seen with infective endocarditis?
The immune response to infective endocarditis can cause glomerulonephritis resulting in protein loss from the bloodstream into the urine
What are the three major criteria required to diagnose infective endocarditis?
Echocardiogram positive for endocarditis
Valvular insufficiency
Positive blood culture result
What is the most common cause of a negative blood culture result in an animal with infective endocarditis?
Due to the initiation of antibiotic treatment prior to the culture
How should infectious endocarditis be treated?
Infectious endocarditis should be treated with high dose bactericidal antibiotics over a long duration (usually for six weeks or more)
Why is infectious endocarditis so difficult to treat with antibiotics?
The vegetations will become densely packed with bacteria interlocked within a biofilm which creates a mechanical barrier limiting antibiotic penetration
What are conduction disorders?
Conduction disorders are abnormalities in the electrical conduction system of the heart
What is an arrhythmia?
An arrhythmia is a variation from the normal cardiac rhythm
What are inherited arrhythmias?
Inherited arrhythmias are a genetically abnormal heart rhythm
What is a primary arrhythmia?
An abnormal heart rhythm caused by an inherent dysfunction in the heart’s electrical conduction system
What is a secondary arrhythmia?
An abnormal heart rhythm caused by external factors
What is Sick Sinus Syndrome?
Sick Sinus Syndrome is a general term for dysfunction of the sinoartial (SA) node
How can Sick Sinus Syndrome be life threatening?
Sick Sinus Syndrome can cause ventricular standstill and paroxysmal supraventricular tachycardia which can both lead to syncope and sudden death
What is paroxysmal supraventricular tachycardia?
Paroxysmal supraventricular tachycardia is the sudden increase in heart rate leading to rapid ventricular contraction
Which breed of dog is predisposed to paroxysmal supraventricular tachycardia?
Female Miniature Schnauzers
What are heart blocks?
Heart blocks are disruptions in the heart’s electrical conduction system leading to an abnormal cardiac rhythm (arrhythmia)
What is a first degree heart block?
A first degree heart block is a delay in the electrical impulse as it travels through the atrioventricular (AV) node
What is a second degree heart block?
A second degree heart block is an intermittent blockage in the electrical impulse as it travels through the atrioventricular (AV) node
What is a third degree heart block?
A third degree heart block is a complete blockage of the electrical impulse as it travels through the atrioventricular (AV) node
What are the four classifications of congenital heart defects?
Failure of closure of foetal structures
Septal defects
Endocardial cushion defects
Great vessel defects
Which three foetal structures can fail to close resulting in congenital disease?
Foramen ovale
Ductus venosus
Ductus arteriosus
What are the consequences of a patent ductus venosus at birth?
A patent ductus venosus will cause blood from the hepatic portal system to bypass the liver and enter the systemic circulation without being detoxified
What is the key clinical sign of a patent ductus venosus?
Hepatic encephalopathy
How does a patent ductus arteriosus cause pulmonary hypertension?
A patent ductus arteriosus will cause abnormal blood flow between the aorta and the pulmonary trunk. The pressure in the left side of the heart is greater than the right side of the heart and thus blood flowing through the aorta will move from high to low pressure into the pulmonary trunk via the patent ductus arteriosus, which will increase the blood flow to the lungs causing a volume overload in the pulmonary circulation resulting in pulmonary hypertension
How does a patent ductus arteriosus cause right ventricular concentric hypertrophy?
Pulmonary hypertension will lead to an increased afterload due to the increased arterial pressure which will result in concentric hypertrophy of the right ventricle to compensate
How does a patent ductus arteriosus cause left ventricular eccentric hypertrophy?
Because there is an excess of blood flowing into the pulmonary circulation, more blood will return from the lungs to the left side of the heart, causing a volume overload and eccentric hypertrophy of the left ventricle
What is the ligamentum arteriosum?
The ligamentum arteriosum is a ligamentous foetal remnant of the ductus arteriosus connecting the pulmonary trunk to the aorta
What are septal defects?
Septal defects are a congenital defect in which there is an opening in the cardiac septa which divide the heart chambers
What is an atrial septal defect?
An atrial septal defect is an opening in the interatrial septum which divides the left and right atria
Patent foramen ovale also classified as atrial septal defect
What are the initial consequences of an atrial septal defect?
The pressure in the left side of the heart is greater than the right side of the heart and this blood from the left atrium will flow from high to low pressure into the right atrium, which will increase the blood flow into the right ventricle and into the pulmonary trunk and to the lungs, causing volume overload in the pulmonary circulation resulting in pulmonary hypertension
What can happen if pulmonary hypertension caused by an atrial septal defect progresses?
Severe pulmonary hypertension will cause increased resistance and this an increased afterload, increasing the pressure within the right side of the heart until the pressure in the right side of the heart surpasses the pressure in the left side of the heart. This will cause the deoxygenated blood from the right side of the heart to shunt into the left side of the heart and enter the systemic circulation, bypassing the lungs. This will cause hypoxia and cyanosis
What is the endocardial cushion?
The endocardial cushion is an embryological structure involved in the formation of the cardiac septa and valves
Which heart structures are affected by an endocardial cushion defect?
Heart valves
List four common blood vessel congenital defects
Dysplasia
Stenosis
Malposition
Transposition
What is blood vessel stenosis?
Blood vessel stenosis is a narrowing of the blood vessel lumen
What are three classifications of stenosis?
Valvular stenosis
Subvalvular stenosis
Infundibular stenosis
What is infundibular stenosis?
Infundibular stenosis is a narrowing of the right ventricle itself
What is the transposition of the great vessels?
Transposition of the great vessels is a congenital defect where the pulmonary trunk and aorta are swapped around
Give an example of a malpositioned congenital blood vessel defects
Persistent right aortic arch
What are the consequences of a persistent right aortic arch?
If the aortic arch develops from the right rather than the left fourth aortic arch, the abnormal positioning can cause the ligamentum arteriosum can form a ring like structure around the oesophagus, causing constriction
What is a key clinical sign of a persistent right aortic arch?
Regurgitation of food due to the constriction of the oesophagus
What is the Tetralogy of Fallot?
The Tetralogy of Fallot is a congenital heart defect resulting is a right to left shunt due to four collective defects
What are the four collective heart defects that cause the Tetralogy of Fallot?
Pulmonic stenosis
Over-riding aorta
Ventricular septal defect
Right ventricular hypertrophy
Which heart defect seen in Tetralogy of Fallot determines the severity of clinical disease?
Pulmonic stenosis determines the severity of clinical disease seen in Tetralogy of Fallot
What is an over-riding aorta?
An overriding aorta is a congenital heart defect where the aorta is positioned directly over both the left and right ventricle
List three examples of congenital pericardial defects
Agenesis
Peritoneopericardial diaphragmatic hernias
Intrapericardial cysts
What is agenesis of the pericardium?
Agenesis is the partial or complete absence of the pericardium
What are peritoneopericardial diaphragmatic hernias?
A peritoneopericardial diaphragmatic hernia is the herniation of the abdominal contents into the pericardium due to the defective separation of the liver from the septum transversum during development
What are intrapericardial cysts?
Intrapericardial cysts are encapsulated haemorrhagic adipose tissue in the pericardium
Which three congenital defects are dogs most prone to?
Patent ductus arteriosus
Pulmonic stenosis
Subaortic stenosis
Which congenital defect are cats most prone to?
Mitral valve dysplasia
Which three congenital defects are cattle most prone to?
Atrial septal defect
Ventricular septal defects
Transposition of great vessels
Which congenital defect are pigs most prone to?
Subaortic stenosis
Which congenital defects are horses most prone to?
It is uncommon for horses to have cardiac congenital defects
What is oedema?
Oedema is excess fluid in the interstitial space
What are the four mechanisms of oedema formation?
Increased vascular permeability
Increased intravascular hydrostatic pressure
Decreased intravascular oncotic pressure
Decreased lymphatic drainage
What are the two main causes of decreased intravascular oncotic pressure?
Failure of albumin production
Loss of albumin
What commonly causes a failure in albumin production resulting in decreased intravascular oncotic pressure?
Hepatic disease
Which two diseases can cause a loss of albumin resulting in decreased intravascular oncotic pressure?
Intestinal malabsorption
Protein losing nephropathy
What is a thrombus?
A thrombus is a solid mass of fibrin with entrapped cells and proteins which form within blood vessels when normal haemostasis is disrupted
What are the three causes of thrombosis?
Endothelial cell damage
Abnormal blood flow
Hypercoagulability
What are the four possible consequences of thrombus formation?
Dissolution of the thrombus
Organisation and re-canalisation
Organisation and aneurysm
Thromboembolism
What is organisation and re-canalisation of a thrombus?
Organisation and re-canalisation of a thrombus is the replacement of the thrombus with fibrous tissue and the formation of new channels to allow for blood flow through the fibrous tissue
What is a thromboembolism?
A thromboembolism is a circulating thrombus which will travel though the bloodstream and cause the blockage of a blood vessel
Which disease commonly causes an aortic thromboembolism in cats?
Aortic thromboembolism can be caused secondary to hypertrophic primary cardiomyopathy in cats
How can hypertrophic primary cardiomyopathy cause a secondary aortic thromboembolism?
The hypertrophy of the myocardium causes blood flow within the heart to become turbulent which can stimulate thrombosis. These thrombi can travel through the blood stream and block the aorta
What is a saddle thrombus?
Saddle thrombus is embolisation of a thrombus at the aortic trifurcation
Which disease commonly causes a pulmonary thromboembolism in dogs?
Pulmonary thromboembolism can be caused secondary to heart worm in dogs
How can heart worm cause a secondary pulmonary thromboembolism?
Adult dirofilaria immitis can reside within the pulmonary trunk stimulating inflammation and abnormal blood flow which can trigger thrombosis. These thrombi can travel through the blood stream and block the pulmonary artery
What is a common iatrogenic cause of venous thrombosis?
Venous catheterisation
What is caudal vena caval thrombosis disease in cattle?
Caudal vena caval thrombosis disease in cattle is thrombosis of the caudal vena cava caused by the erosion of hepatic abscesses into the caudal vena cava
What is an aneurysm?
An aneurysm is an abnormal swelling of the blood vessel wall
What is a dissecting aneurysm?
A dissecting aneurysm is the leakage of blood between the layers of the blood vessel wall caused by damage to the tunica intima
What is a pseudoaneurysm?
A pseudoaneurysm is a localised haematoma outside of a blood vessel caused by damage to the blood vessel wall
What is vascular torsion?
Vascular torsion is the twisting or rotation of blood vessels
(T/F) Vascular torsion is more common in veins
TRUE. Vascular torsion is more common in veins as they are lower pressure vessels compared to arteries
How can vascular torsion cause tissue necrosis?
Vascular torsion will decrease or cutoff the blood supply to the tissues supplied by those vessels resulting in hypoxia and eventually tissue necrosis
(T/F) Vascular rupture is more common in veins
FALSE. Vascular rupture is more common in arteries due to their high pressure
What are the three possible causes of an arterial rupture?
Trauma
Erosion
Spontaneous
Which disease can cause an erosive arterial rupture?
Guttural pouch mycosis
Which species is most prone to a spontaneous vascular rupture?
Race horses
Which species are most prone to aortic and carotid arterial ruptures?
Horses
Which breed of horse is particularly susceptible to an aortic rupture?
Friesian horses
Where along the aorta is a rupture most likely to occur in Friesian horses?
Aortic arch
What is arteriosclerosis?
Arteriosclerosis is the thickening and stiffening of blood vessels resulting in the narrowing of the blood vessel lumen and loss of elasticity
What are the two main causes of arteriosclerosis?
Ageing
Hypertension
Which two species are susceptible to arteriosclerosis?
Cats
Rabbits
What is atherosclerosis?
Atherosclerosis is the thickening and stiffening of the blood vessels caused by fat deposition
Which two underlying conditions can cause atherosclerosis in dogs?
Hypothyroidism
Diabetes mellitus
What are the two key histological features of atherosclerosis?
Cholesterol clefts
Fatty plaques
What is vasculitis?
Inflammation of the blood vessels
Which virus is a common cause of vasculitis?
Feline infectious peritonitis (FIP)
What is omphalophlebitis (naval ill)?
Omphalophlebitis (naval ill) is the inflammation of the umbilical vein
What is vena caval syndrome?
Vena caval syndrome is partial or complete occlusion of the vena cava
List three examples of lymphatic disease
Lymphangiectasis
Lymphatic rupture
Lymphangitis
What is lymphangiectasis?
Lymphagiectasis is the dilation of the lymphatic vessels
Which two species are most susceptible to a thoracic duct rupture?
Dogs
Cats
What kind of effusion would result from the rupture of a lymphatic vessel?
Chylous effusion
What is a chylothorax?
A chylothorax is the accumulation of lymphatic fluid within the thoracic cavity
What is a chylous ascites?
A chylous ascites is the accumulation of lymphatic fluid in the peritoneum
What is lymphangitis?
Lymphangitis is inflammation of the lymphatic vessels
