6. Myxomatous Mitral Valve Diseases In Dogs

Question 1

Valvular disease

Answer 1

Most common acquired disease
Small breeds
Male> female
King Charles cavalier, dachshund, poodle

Mitral valve involvement - increase pulmonary pressure - cardiogenic pulmonary oedema

Tricuspid valve involvement - incr. venous pressure - signs of rs chf

Question 2

Compensatory mechanisms

Answer 2

Valvular interstitial cells transformed- remodeling
Ecm expands - alteration and loss of valvular collagen - malfunction of valves
RASS- Na and h2o retention - incr. blood vol. - ventricular enlargement

Question 3

Lesions and consequences

Answer 3

Thickening of valve leaflets
Knotting
Ruptured chordae tendinae
Dialated mitral ring

Mitral valve prolapse
Mitral insufficiency
LA and LV dilation

Question 4

Dx

Answer 4

Physical exam - systolic heart murmur + ls/rs chf signs

Echocardiography
See regurgitation of blood
Thickening of valves
Dilation

Radiography - enlarged chambers

Question 5

Grading

Answer 5

A- high risk patient, no identifiable cardiac disorder
B1- asymptomatic, no evidence of cardiac remodeling
B2- asymptomatic, with cardiac remodeling
C- past/current cs of heart failure
D- cs of Herat failure. End stage

Question 6

Treatment

Answer 6

B2- Pimobendan
Ace inhibitors- enapril
Avoid high salt foods

C- treatment of chf 
Oxygen 
Furosemide 
Pimobendan 
Spironolactone (ace inhib)

Question 7

Endocarditis

Answer 7

Large breed
Bacterial infection - staph, strep, ecoli, bartonella
Aortic stenosis