Pathology of Vascular Disease

Question 1

endocardium

Answer 1

innermost layer of the heart; surrounds the walls of the chambers and the valves

Question 2

mural vs valvular endocardial disease

Answer 2

mural: disease of ventricular wall endocardium (uncommon)

valvular: disease of valve endocardium (common)

Question 3

valvular endocarditis

Answer 3

inflammation of the valve endocardium caused by bacterial infection

Question 4

white spotted kidney disease

Answer 4

septicemia spread to the kidneys via valvular endocarditis (bacteria breaks off –> travels in capillaries –> reaches glomeruli in kidneys)

lesion: white spots around kidneys

Question 5

what bacteria causes white spotted kidney disease in cattle vs horses

Answer 5

cattle: e. coli
horses: actinobacillus equuli

Question 6

diamond skin disease

Answer 6

septicemia spread to the skin via embolization of valvular endocarditis in PIGS

causes vasculitis and thrombosis of dermal vessels –> regions of infarct and necrosis

Question 7

what bacteria causes diamond skin disease in pigs

Answer 7

E. rhusiopathiae

Question 8

pericardium

Answer 8

serous sac surrounding the heart; should have a very small amount of fluid in health

Question 9

pericardial disease

Answer 9

pericardial effusion causes the heart to be unable to expand

causes a diastolic dysfunction

Question 10

cardiac tamponade

Answer 10

severe, rapid decrease in cardiac output secondary to pericardial effusion

if slow decrease in CO –> pericardial sac may stretch and get compensation

if rapid –> can’t compensate

Question 11

traumatic reticule-pericarditis (TRP)

Answer 11

hardware disease

caused by ruminant ingestion of a nail –> travels to rumen and reticulum –> punctures through reticulum into the heart –> spreads bacteria into pericardial sac

lesion: fibrinous/exudative infiltrate in pericardium

sequela: right sided heart failure

Question 12

what is the most common primary cardiac neoplasia in dogs

Answer 12

hemangiosarcoma

Question 13

where does hemangiosarcoma usually affect the heart

Answer 13

right auricle

Question 14

is hemangiosarcoma benign or malignant

Answer 14

highly malignant; often metastasizes to lungs

Question 15

how does hemangiosarcoma cause death

Answer 15

acute death from ruptured HSA –> blood fills pericardium –> diastolic dysfunction –> rapid loss of CO –> cardiac tamponade –> death

Question 16

what is the most common metastatic tumor to the heart

Answer 16

lymphoma; can be primary but rare

Question 17

examples of primary cardiac lymphoma

Answer 17

cattle: bovine leukemia virus (BLV, retrovirus); causes B cell lymphoma

chickens: Marek’s disease; galled herpesvirus-2 causes T cell lymphoma

Question 18

atherosclerosis

Answer 18

formation of a plaque of macrophages + LDL/cholesterol

degenerative disease causing vessel wall thickening and narrowing of the lumen (subintimal - located in the wall)

NOT common in domestic animals; if in a dog then sub clinical in a mini schnauzer

Question 19

arteriolosclerosis

Answer 19

smooth muscle proliferation and collagen deposition in the vessel wall

degenerative disease causing vessel wall thickening and narrowing of lumen

associated with hypertension

VERY common in domestic animals

Question 20

vasculitis

Answer 20

inflammation within the vessel wall - infectious or non infectious

causes destruction of the vessel leaving it vulnerable to thrombosis

Question 21

what is the top sign of aspergillus vasculitis

Answer 21

epistaxis (nose bleed)

Question 22

what causes caval disease in cows

Answer 22

mycotic rumenitis from zygomyces infection

Question 23

caval disease in cows mechanism

Answer 23

grain overload –> rumen acidosis –> kills commensal bacteria and damages epithelium –> zygomyces proliferation –> invades damaged epithelium –> invades vessels

travels from rumen to liver to heart to lungs
- rumen
- portal vein
- liver
- caudal vena cava
- RA (tricuspid valve endocarditis)
- RV
- PA
- lungs –> lung hemorrhage

Question 24

lesions of caval disease in cattle

Answer 24

rumen acidosis
liver abscesses
tricuspid valve endocarditis
pulmonary hemorrhage

Question 25

what causes caval disease in dogs

Answer 25

dirofilaria immitis (parasitic) infection

Question 26

mechanism of caval disease in dogs

Answer 26

adults live in the pulmonary arteries and travel to RA when no more room

parasites shed foreign antibodies/proteins causing pulmonary hypertension

leads to R sided heart failure

R-HF: obstruction of CVC –> portal hypertension –> hepatomegaly –> ascites

Question 27

immune mediated vascular disease

Answer 27

type III hypersensitivity caused by immune complexes that deposit in the vascular wall and activate complement, which leads to vascular necrosis

Question 28

purpura hemorrhagica

Answer 28

type III hypersensitivity reaction affecting small capillaries in HORSES

caused by STREP. EQUI vaccine or infection
- bacteria resembles endothelium
- immune response targets strep and endothelium

lesions: vasculitis –> EDEMA + HEMORRHAGE

can be fatal