CVS Pathology Image-Based Learning

Heartworm (Dirofilaria immitis)

Heartworm microfilaria from canine blood

Mosquitos (culex pipiens pipiens and stegomyia)

Heartworm - Dirofilaria immitis "Vena Cava Syndrome"

Worms in the RHS of the heart and vena cava leading to tricuspid valve problems and blood flow obstruction

Heartworm (Dirofilaria immitis)

Schistosoma (blood fluke)

Granuloma formation with calcification and fibrosis due to schistoma egg accumulation in tissues

Dilation

Concentric hypertrophy of the heart

Eccentric hypertrophy of the heart

Patent ductus arteriosus

Atrial septal defect - Systemic to pulmonary shunting (left to right)

Continuous washing machine murmur, basil

Ventricular septal defect

Systemic to pulmonary shunting (left to right)

Right apical to basilar systolic, the smaller the defect, the louder the murmur

Pulmonic stenosis

Pulmonic stenosis

Post stenotic dilation

Aortic and subaortic stenosis (SAS)

Pressure overload in LV → concentric hypertrophy

AV valve dysplasia

Shortening, rolling and thickening of leaflets

Incomplete separation of valve components from ventricular wall

Elongation, shortening, fusion, thickening of chordae tendineae

Direct insertion of the vale edges into papillary muscle

Atrophy, fusion, mal-position of papillary muscles and chordae tendineae

Tetralogy of Fallot (Partial Transposition)

Persistent right aortic arch where the aorta forms from right 4th aortic arch instead of left

Megaoesophagus (E)

Aspiration pneumonia

Peritoneal pericardium diaphragmatic hernia

Left - lymphocyst of the heart

Right - haemocyst of the heart

Ectopia cordis

Dilated (DCM) Primary Cardiomyopathy

Dilation of atria and ventricles, increased annulus circumference, eccentric hypertrophy of ventricles, papillary muscles often flattened/ atrophic

Hypertrophic (HCM) Primary Cardiomyopathy

Asymmetrical septal hypertrophy to symmetrical hypertrophy of the LV, replacement fibrosis

Saddle thrombus at the aortic trifurcation (cat)

Restrictive Primary Cardiomyopathy

Endomyocardial fibrosis → heart unable to expand, excessive moderator bands of fibrosis in cats, dilated atria with normal ventricular size

Arrhythmogenic right ventricular cardiomyopathy (Primary)

+/- RV hypertrophy, RA dilation, fibro-fatty replacement of cardiomyocytes

Myocardial Necrosis (Brain-heart syndrome)

Multifocal myocardial necrosis associated with neurological disease of diverse origin; cardiomyocyte mineralisation, fragmentation and loss of cross striations

White muscle disease (Vitamin E/ selenium deficiency)

Myocyte necrosis and mineralisation (white muscle) → death via ventricular arrhythmia

Mulberry heart disease (Vitamin E/ selenium deficiency)

Myocyte necrosis and mineralisation (white muscle) → death via ventricular arrhythmia

Multifocal necrosis with widespread epicardial and myocardial haemorrhage, fibrinoid arteriolar necrosis, hepatosis dietetica

Hydropericardium

Secondary myocardial disease (taurine deficiency)

Dilated Cardiomyopathy-like phenotype

Secondary myocardial disease (taurine deficiency)

Masson’s Trichrome stain - Dilated Cardiomyopathy-like phenotype

(pink = myocytes, blue = collagen)

Cardiomyocyte loss, replacement fibrosis, compensatory hypertrophy

Endocardial mineralisation

Myxomatous valve degeneration (MVD)/ Endocardiosis

Thickened (nodular) and shortened valves with smooth endocardial surface, ‘Jet lesions’ / endocardial fibrosis in the left atrium, myofibroblastic proliferation, deposition of acid mucopolysaccharides within valvular stroma

Valvular insufficiency (regurgitation)

Endocardial (endothelial) injury == “jet lesions”

Bacterial vegetative valvular endocarditis (Truperella pyogenes)

Mammary gland; mitral valve. Necrosuppurative mastitis and chronic endocarditis with endocardial plaques, pus

Heart; inflammation of the valve

Bacterial vegetative valvular endocarditis

Ox, tricuspid valve endocarditis

Friable, yellow-to-grey-to-red masses of fibrin (vegetations), fibrotic with chronicity

Bacterial vegetative valvular endocarditis

Horse, aortic valve. Chronic aortic valve endocarditis with endocardial plaques; friable, yellow-to-grey-to-red masses of fibrin (vegetations), fibrotic with chronicity

Bacterial vegetative valvular endocarditis

Mitral valve. Chronic bacterial endocarditis

Lamellar fibrin, mixed leukocytes, granulation tissue (chronic), +/- bacterial colonies

Endocardiosis

Smooth in appearance

Endocarditis

Rough in appearance

Areas of haemorrhage, fibrosis, bacteria

Hydropericardium

Goat kid, hydropericardium. Secondary to CHF. Tricavitary effusion present.

Excess clear fluid within the pericardial cavity

Haemopericardium

Secondary to ruptured RA hemangiosarcoma

Pure blood in the pericardial cavity

Serous atrophy of fat (SAF)

Lipid replaced by proteinaceous fluid - gelatinous and translucent

Goat, fibrinous pleuropneumonia and pericarditis. Mannheimia haemolytica

Traumatic reticulopericarditis (TRP)/ Hardware disease

Wire penetration through the reticulum wall, diaphragm, pericardium

Seeding of bacteria in the pericardium (bacterial pericarditis); fibrosis - leading to constrictive pericarditis, right sided heart failure

Epicardium covered in a thick mat of fibrin

Left sided congestive heart failure - pulmonary congestion and oedema

Diffusely wet and heavy lungs which feel rubbery, ooze fluid on cut surface

Right sided congestive heart failure - Liver

Chronically congested and enlarged nutmeg liver, central veins congested first, atrophy of zone 3 sinusoids (central vein area) → fibrosis and loss of hepatocytes

Right sided congestive heart failure - subcutaneous oedema

Haemangiosarcoma

Endothelial cells, right atrium and auricle

Paraganglioma (chemodectoma)/ aortic body tumour

Concentric hypertrophy

Lymphoma

Gross: Multifocal to coalescing pale tan to white nodules, varied demarcation

Histological: Sheets of neoplastic cells with disruption of the surrounding myocardium

Histiocytic sarcoma

Fibrinoid vascular necrosis

Endothelial damage characterised by accumulation of serum proteins and polymerised fibrin within the vessel wall

Homogenous eosinophilic material within the vessel wall which obscures cellular detail

Arteriosclerosis of vessels

Hardening of the arteries and loss of elasticity, mineralisation of the tunica media, arterial wall thickening and luminal narrowing

Atherosclerosis

Prominent pale tan vessels, fibrofatty plaque, arterial wall thickening and luminal narrowing

Atherosclerosis of vessels

Atheromas (fibrofatty plaque), arterial wall thickening and luminal narrowing

Medial hypertrophy and hyperplasia of vessels

Pulmonary arteries; myofibroblast proliferation and hypertrophy within the tunica media as a result of hypertension and hyperperfusion - hypoxia

High Altitude disease: Medial hypertrophy and hyperplasia/ Brisket disease

Concentric hypertrophy of the RHS of the heart → right-sided heart failure and increased hydrostatic pressure

Aortic rupture

Equine viral arteritis virus

Gross: oedema, congestion, haemorrhage, abortion

Histopathology: fibrinoid vascular necrosis, lymphocytic vasculitis

Orbivirus infection

Cardiac and pulmonary presentations - alveolar oedema, widespread haemorrhages, massive pulmonary oedema with frothiness

Bluetongue virus - Viral vasculitis

Oral oedema with blue tongue (cyanosis and hypoxia), coronary band alopecia and ulceration, oral peticiations, oro-nasal discharge (muco-purulent)

Fibrinoid necrotising arteriolitis (Swine haemorrhagic viruses)

Rickettsia - Ehrlichia ruminantium (Heartwater/ cowdriosis)

Gross pathology: hydropericardium, hydrothorax, splenomegaly

Histopathology: small vessel degeneration +/- vasculitis, colonies of bacterial within endothelial cytoplasm

Rickettsia - Rocky mountain fever (Rickettsia rickettsiii)

Gross pathology: oedema of ears and muzzle, petechiation of mucous membranes and skin, lymphadenomegaly with haemorrhage, haemorrhagic colitis

Histopathology: necrotising vasculitis of small veins, capillaries and arterioles, perivascular mononuclear inflammation

Mycotic abomastitis and rumenitis

Gross pathology: multifocal ulcers with necrosis which can be transmural and lead to peritonitis, can spread to the liver (multifocal necrotising hepatitis)

Histopathology: necrotising vasculitis with venous thrombi, fungal hyphae within vessel walls

Parasitic (verminous) vasculitis

Gross pathology: adult nematodes in pulmonary arteries and right ventricle, right ventricle concentric hypertrophy

Histopathology: Pulmonary arteries and right ventricle endocardium: intimal proliferation, medial hypertrophy and arteritis/ endocarditis (lymphoplasmacytic or eosinophilic), circulating microfilariae seen within alveoli of lungs

Verminous vascultiits

Dog heart, pulmonary artery thrombus, infarction, multiple pulmonary embolisms

Treated for heartworm 3 years prior - right sided heart failure

Ecchymosis, haemorrhage, infarction of the tongue, vasculitis

Leukocytoclastic vasculitis

Glomerular; basophilic stippling

Feline infectious peritonitis - Coronavirus

Phlebitis

Feline infectious peritonitis

Lymphoedema

Intestinal Lymphangiectasia

A. Intestinal villi are expanded by ectasia of the lymphatic vessels (raised white areas). Lymphangiectasia can be a congenital developmental disorder of the lymphatic vessels, or it can be acquired secondary to lymph vessel obstruction caused by granulomatous or neoplastic diseases.

B. Lacteals are dilated (asterisks), thus resulting in diminished lymph absorption by lacteals in the lamina propria and subsequent loss of protein (hypoproteinemia) and other nutrients into the intestinal lumen. H&E stain. PBVD

Lymphangiectasia

Granulomatous inflammation

Lymphangitis

Granulomatous lymphangitis in Johne's disease in a cow

Epizootic lymphangitis (horses and mules)

Histoplasma capsulatum vs histoplasma farcinonosum (HCF)

Pyogranulomatous ulcerative dermatitis and lymphangitis

Chylothorax

Chyle leakage or rupture into the thorax

Gross: opaque, thin, white fluid with lipid droplets filling thorax

Lymphangiosarcoma - ventral abdomen

Gross: ill defined area of soft, gelantinous skin with bruised appearance

Histopathology: channels contain few, if any blood cells (VERY similar to haemangiosarcoma)