Canine Cardiomyopathies Flashcards
(31 cards)
What breeds tend to get dilated CMO?
Large/giant breeds. A high proportion of some breeds are affected
What CMO do boxers get?
Their own unique CMO –> Arrhythmias and sudden death, not necessarily with dilatation
CMOS can be secondary to …
Nutrition, toxic, infectious and endocrine issues.
Generally, your prognosis for a CMO is
Guarded to poor
Boxers get their own CMO, which is …
Arrhythmogenic right ventricular CMO of boxers (BOXER CMO)
Boxer CMO is distinct from DCM, but …
Some boxers will get common or garden DCM instead of boxer CMO
Outline the incidence of DCM in dogs.
Large to giant breeds
4-10 years of age
M>F
Rare in dogs
50% of the male of this breed, and 33% of the female of this breed, will eventually develop DCM
Doberman pinschers
Outline the aetiology of DCM
Idiopathic
Strong genetic predisposition in some breeds
Explain the understanding between genetic predispositions to DCM in Great Danes, Portuguese Water Dogs, and boxers
Great Danes - X linked recessive in some
Portuguese Water Dogs - Autosomal recessive
Boxers - Autosomal dominant
DCM most likely represents the end stage of a variety of pathological conditions
I should already fucking know this but I forgot
Briefly explain the pathophysiology of DCM
Decreased ventricular contractility - systolic dysfunction - low output HF
- weakness, syncope, cardiogenic shock
Progressive chamber enlargement, failure of valve leaflets to coast, eventual diastolic “stiffness:
- R & L sided CHF
Atrial fibrillation is a common pathological development in DCM dogs. The consequences of this are
Loss of the atrial kick, persistent tachycardia, lower cardiac output and disease progression
As well as atrial fibrilation, what other arrhythmia tends to develop in DCM dogs that can cause sudden death?
Ventricular tachyarrhythmias.
Thinking of a spectrum of conditions, with syncope, arrhythmias and sudden death (far left), and atrial fibrillation (right), place the breeds “boxer, Doberman, Great Dane and Irish wolfhound” on this spectrum. Think about where CHF fits into this picture as well.
Syncope. Atrial fibrillation
Arrhythmias
Sudden death.
Boxer. Doberman. Great Dane. Irish wolf hound
Age of dogs with CHF due to DCM (generally)? Male or females worse?
Generally 4 - 10
Males show clinical signs earlier
What stage often precedes the clinical stage of CMOs such as DCM? How can this be detected?
Prolonged occult stage.
Echocardiography
What are the clinical features of CMO dogs such as those with DCM
Exercise intolerance Weakness Lethargy Tachypnoea Dyspnoea Cough Anorexia Abdominal swelling Syncope Loss of muscle mass (marked)
Two major factors involved in your diagnosis are:
Compatible signalment and history
Systolic mitral and or tricuspid murmur (may be quiet/soft)
Why might the systolic mitral and or tricuspid murmur be quiet/soft in DCM dogs?
Weakened muscular contractions
List possible signs that may or may not be present in CMO dogs such as those with DCM
Gallop
Irregularly Irregular arrhythmia, pulse deficit
MMB pallor change with slow CRT, cold extremities and weak femoral pulses
Signs of CHF
What are the treatment principles for DCM dogs?
A diuretic to relieve congestion
A positive inotrope to support ventricular function
An ACEI to oppose RAAS, reduce salt and water retention and mildly vasodilation
Anti-arrhythmic drug(s) as needed
Do we treat during the occult stage? If so, how?
It is uncertain if this actually helps. May use an ACEI (enalapril), diuretic (spironolactone), Beta-blockers and anti-arrhythmic drugs.
How do we treat the overt stage of DCM?
Similar to CVHD with anti-arrhythmic therapy often needed EXERCISE RESTRICTION initially Frusemide (lowest effective dose) Pimobendan ACEI
