Lecture 20 9/27/24 Flashcards
What are the characteristics of feline idiopathic hypertrophic cardiomyopathy?
-common in all breeds
-most common in young adult males
-sudden death due to arrhythmia is common
Which cat breeds have inherited feline idiopathic HCM?
-Maine coons
-ragdoll
What are the necropsy findings in cats with feline idiopathic HCM?
-thickened intraventricular septum and left ventricular free wall
-dilated left atrium
What are the characteristics of an end-stage HCM heart?
-fibrotic and relatively thin-walled
-will still weigh more than a normal heart
What are the characteristics of HCM in canines?
-uncommon
-typically associated with an underlying cause
What are the characteristics of feline thyrotoxic cardiomegaly?
-seen in older cats
-associated with thyroid adenomatous hyperplasia/hyperthyroidism
-not the same as HCM which is a primary myocardial disease
What are the characteristics of feline endomyocarditis?
-LV endocardial fibrosis complex
-inflammatory stage most often occurs in young cats
-history typically includes a stressful event
-resp. distress is most common presentation
What are the necropsy findings in feline endomyocarditis?
-enlarged heart
-possible discoloration of aortic outflow tract
-LV hemorrhage and inflammation in acute cases
-LV endocardial fibrosis in chronic cases
Which bacteria is associated with feline endomyocarditis?
Bartonella spp.
What are the characteristics of endocardiosis?
-aka myxomatous mitral valve degeneration
-common aging change in dogs
-common cause of CHF in small dogs
-predisposed to chordae tendinae rupture and actue clinical decomp.
What is the gross lesion associated with endocardiosis?
smooth white-gray valvular nodules
What is the microscopic lesion associated with endocardiosis?
myxomatous nodules expanding valves
Which breed is endocardiosis most common in?
Cavalier King Charles spaniels
What is endocarditis?
inflammation of the endocardium that is typically bacterial and valvular
What are the characteristics of endocarditis in dogs?
-often seen in large breeds older than 5 years
-endocardiosis is NOT a predisposing factor
-left side is most affected
Which bacteria are associated with endocarditis in dogs?
-Bartonella; aortic
-Streptococcus; mitral/polyarthritis
-gram neg. bacteria; any valve
Where is endocarditis most common in different large animal species?
-horses: left side; aortic > mitral
-ruminants: right side; tricuspid > pulmonic
-camelids: right side; tricuspid > pulmonic
What is the gross lesion associated with endocarditis?
rough tan to red material adhered to valves
What is the microscopic lesion associated with endocarditis?
fibrin and bacteria
What are the consequences of endocarditis?
-56% mortality rate
-valvular insufficiency and CHF
-septic emboli and multi-organ infarcts
What are the characteristics of endocardial fibrosis?
-end-stage lesion of feline endomyocarditis
-secondary to chronic turbulence leads to diffuse opacity of endocardium
-associated with jet lesions
-occur in atria above AV valves with endocardiosis
What is a jet lesion?
-focal endocardial fibrosis secondary to turbulence
-raised plaque that is often linear
What are the characteristics of false tendons/excessive moderator bands?
-web-like network of fibrous strands in LV
-perpendicular to long axis of heart
-not attached to valve leaflets
-most common in cats
What are the characteristics of congenital hematomas?
-most common in ruminants
-filled with blood or serum
What are the characteristics of CHF?
-get pulmonary congestion and edema
-see liver congestion
-pulmonary hemosiderosis/brown coloring possible, esp. with heartworms
-brown color caused by hemosiderin within alveolar macrophages
What are the possible types of edema seen in CHF?
-ascites
-pericardial effusion
-pleural effusion
-dependent subcutaneous edema
-brisket edema
What is the pathogenesis of brisket edema?
-hypoxia results in exaggerated hypoxic pulmonary vasoconstriction
-vasoconstriction causes pulmonary hypertension
-hypertension leads to right ventricular hypertrophy and CHF
What are the characteristics of “nutmeg liver?”
-chronic passive congestion of liver
-see centrilobular distribution of dilated sinusoids
What is the pathogenesis of saddle thromboembolus?
-feline cardiomyopathy leads to turbulence in dilated left atrium
-turbulence results in formation of left atrial thrombus
-thrombus embolizes to aortic bifurcation/trifurcation
-ischemia and necrosis of hind limbs occurs
What are the characteristics of dirofilariasis?
-nematodes in pulmonary arteries and right heart
-huge worm load can cause vena caval syndrome
-pulmonary artery endothelium roughens; proliferative endarteritis
-lungs can be brown due to hemosiderosis
What are the characteristics of Strongylus vulgaris larval migration in horses?
-thrombosis in cranial mesenteric artery results in ischemia of intestines and colic
-aneurysm occurs due to weakening of vessel wall by larvae and inflammation
