Canine Degenerative Valve Disease

Question 1

What is the most common cause of cardiac morbidity and mortality in dogs?

Answer 1

Degenerative mitral valve disease

Question 2

What is the most common signalment for degenerative valve disease in dogs?

Answer 2

Small to medium breeds
> 8 yrs old
Cavalier king charles, dachshunds

Question 3

Layers of the mitral valve:

Answer 3

Atrialis > spongiosa > fibrosa > ventricularis

Question 4

Pathology of DMVD:

Answer 4

edematous nodules of varying size and location > plaque like elevations>
thickened chordae tendinae (begins proximally then > generallized) > distortion and contraction of the valve leaflets

Question 5

What happens when the chordae tendineae rupture?

Answer 5

Hylalinization and disintegration of collagen bundles
LEads to MV prolapse and flail

Question 6

What can cause a jet lesion?

Answer 6

High velocity jet of regurgitation. Commone sequelae of left atrial tear

Question 7

Explain the pathophysiology of DMVD:

Answer 7

Mitral regurgitation > left sided volume overload (l eccentric hypertrophy) > left sided CHF

Question 8

Clinical signs of left sided CHF

Answer 8

Tachypnea/dyspnea
Cough
Syncope
Pulmonary hypertension (pulmonary edema)

Question 9

What kind of murmur do you expect to find on PE for DMVD?

Answer 9

Apical systolic murmur
PMI: mitral

Question 10

ACVIM CHF Stage A:

Answer 10

no audible heart murmur
At risk breeds (cavalier, dachshunds, mini and toy poodles)
No treatment other than regular evaluations

Question 11

ACVIM CHF Stage B1:

Answer 11

Audible heart murmur
Asymptomatic
MR not severe enough to meet criteria for medical treatment (but cna be some left sided enlargement)
Reevaluation every 6-12 months

Question 12

ACVIM Stage B2:

Answer 12

Audible heart murmur
Asymptomatic
MR severe enough to result in cardiac remodeling sufficient to recommend tx
Pimobendan +/- ACE-inhibitor (if hypertensive), +/- cough supressants
Diet: sodium restriction

Question 13

ACVIM Stage C

Answer 13

Disease severe enough to cause current or past clinical signs of heart failure
Acute: Furosemide, oxygen, pimobendan, sedation
Chronic: Diet, ACE-inhibitor, furosimide, spironolactone, pimobendan

Question 14

ACVIM Stage D:

Answer 14

Clinical signs of failure refractory to standard treatment
Consider switching from furosemide to torsemide (very potent loop diuretic)

Question 15

Prognosis for DMVD:

Answer 15

Usually slow, progressive
Can take years for some dogs to develop CHF, and some may never
Once pt progresses to left sided CHF > survival time is approx 12 mo