Acquired CV Disease in Dogs Flashcards
What is the signalment/predisposition for degenerative mitral valve disease?
Commonly affects older, smaller breeds of dog e.g. Cavalier King Charles Spaniels, Terriers, Poodles etc.
What is usually the initial findings of degenerative mitral valve disease (DMVD)? Is the disease progressive?
Usually a left apical systolic murmur (leak in the valve), which gets louder as the disease progresses. (Louder than grade III suggests dogs may be more advanced)
Do all dogs with DMVD die of cardiac disease or go into heart failure?
No, it has a slow progression. Dogs may never develop heart failure due to DMVD.
How can dogs with DMVD be classified into “classes” based on stages?
Class B1 - no cardiomegaly, no signs
Class B2 - cardiomegaly, no signs
Class C - signs of heart failure e.g. breathlessness, coughing.
Class A - Refractory signs of HF.
How is DMVD diagnosed?
You need to demonstrate mitral regurgitation. In many cases this is from a presumptive diagnoses on CS, and definitive diagnoses using imaging (doppler echocardiography) may not be sought.
As DMVD progresses, what might you see on imaging techniques that indicate the disease is progressing?
Progressive left sided cardiac enlargement (cardiomegaly). If in HF, it is usually left sided and can be diagnosed on radiographs from the presence of pulmonary congestion and oedema.
Should dogs with early DMVD recieve therapy?
There is no convincing evidence that dogs in this stage (without clinical signs or cardiomegaly, once has cardiomegaly this is controversial) there is no evidence to suggest that therapy benefits.
At what stages of DMVD is therapy proven to benefit the patient?
Once the patient has gone into heart failure (e.g. cardiomegaly and HF signs)
What is the ideal protocol for treating dogs with advanced stage DMVD causing heart failure? What drugs would you give?
Minimum give Furosemide and Pimobendan. May also give ACEi and/or spironolactone. Patient may be given up to all 4, but min the first 2, and then add others.
What is the signalment/predisposition for dilated cardiomyopathy (DCM)?
Usually affects large breed dogs >25kg. Commonly affected breeds include Boxers, Dobermans, Great Danes and Cocker Spaniels. Prevalence also increases with age. Males more succeptible.
What is usually the initial findings of DCM? Is the disease progressive? Is it likely to progress to heart failure?
More commonly associated with arrhythmias, may have a soft left apical systolic murmur (due to dilatation of the heart). The disease is progressive, and is likely to progress to HF.
How is DCM diagnosed?
A definitive diagnoses is made with Echocardiography showing dilatation of the heart (particularily left ventricle) and impaired systolic function.
How is the systolic function measured in DCM? How would DCM affect this?
Systolic function is measured by measuring fractional shortening (%) heart chamber using echocardiography. DCM decreases the fractional shortening percentage.
How often is a preclinical case of DCM seen? Why is this less than DMVD? Is there any therapy given to preclinical cases (i.e. before heart failure) DCM cases?
DCM is usually an arrhythmia rather than a murmur (DMVD), so it is much less likely to see a clinical case. There is some evidence that Pimobendan and ACEi may delay onset of clinical signs.
Once a dog with DCM has gone into heart failure, what is the protocol for therapy?
Similar to that of DMVD (i.e. Furosemide, Pimobendan, ACEi, may give Spironolactone also). Much more likely will need an anti-arrhythmic than in DMVD.
